:Could someone tell me where I can find the alignment data for a Packard Bell model 36?
:Thanks
:Steve
:
:

:Steve,
:I found this here on NA under resourcces
:http://www.nostalgiaair.org/Resources/869/M0012869.htm
:Does that match your tube lineup?
:Jeff
:
::Could someone tell me where I can find the alignment data for a Packard Bell model 36?
::Thanks
::Steve
::
::
:

Once you have that done the front end can be aligned on each band. The two 35 pF capacitors below the 2F7 adjust where stations come in on the dial, one for short wave the other for AM, standard broadcast. Adjust these so stations come in at the proper point. A good point for AM is 14ooKHz, for Short Wave, try 12MHz.
After that adjust the two 35pF capacitors above the 2F7 for peak. FOr AM a good point is around 600KHz. For Short wave I would try around 7MHz.

If stations come in with birdies, it usually means the IF is oscillating. You would then need to detune the IF. On each If transformer turn one screw by 1/8 clockwise, the other by 1/8 turn counter clockwise. That should take the birdie out.

Best Regards,

Bill Grimm

:Hi Steve,
: To align the IFs set your signal generator to 460 KHz, modulation on. Turn the band switch to Short wave and to a place on the dial without signal.
: Inject the modulated 460KHz from the signal generator on to the grid of the 2F7, ground to chassis. The modulated signal should be heard from the speaker. The volume control should be about 1/4 of full range. Adjust the signal generator so the sound is at a comfortable level.
: Attach an AC meter to the speaker terminals. Adjust the IFs for maximum signal. As you tune the IFs keep cutting back on the signal generator signal level so the sound does not get too loud. This is not just to be easy on your ears, but it also prevents AGC action from messing up the alignment.
:
: Once you have that done the front end can be aligned on each band. The two 35 pF capacitors below the 2F7 adjust where stations come in on the dial, one for short wave the other for AM, standard broadcast. Adjust these so stations come in at the proper point. A good point for AM is 14ooKHz, for Short Wave, try 12MHz.
: After that adjust the two 35pF capacitors above the 2F7 for peak. FOr AM a good point is around 600KHz. For Short wave I would try around 7MHz.
:
: If stations come in with birdies, it usually means the IF is oscillating. You would then need to detune the IF. On each If transformer turn one screw by 1/8 clockwise, the other by 1/8 turn counter clockwise. That should take the birdie out.
:
:Best Regards,
:
:Bill Grimm
:
:

:Thanks for the information. As soon as I change the capacitors I try your alignment procedure.
:Thanks
:Steve
:
::Hi Steve,
:: To align the IFs set your signal generator to 460 KHz, modulation on. Turn the band switch to Short wave and to a place on the dial without signal.
:: Inject the modulated 460KHz from the signal generator on to the grid of the 2F7, ground to chassis. The modulated signal should be heard from the speaker. The volume control should be about 1/4 of full range. Adjust the signal generator so the sound is at a comfortable level.
:: Attach an AC meter to the speaker terminals. Adjust the IFs for maximum signal. As you tune the IFs keep cutting back on the signal generator signal level so the sound does not get too loud. This is not just to be easy on your ears, but it also prevents AGC action from messing up the alignment.
::
:: Once you have that done the front end can be aligned on each band. The two 35 pF capacitors below the 2F7 adjust where stations come in on the dial, one for short wave the other for AM, standard broadcast. Adjust these so stations come in at the proper point. A good point for AM is 14ooKHz, for Short Wave, try 12MHz.
:: After that adjust the two 35pF capacitors above the 2F7 for peak. FOr AM a good point is around 600KHz. For Short wave I would try around 7MHz.
::
:: If stations come in with birdies, it usually means the IF is oscillating. You would then need to detune the IF. On each If transformer turn one screw by 1/8 clockwise, the other by 1/8 turn counter clockwise. That should take the birdie out.
::
::Best Regards,
::
::Bill Grimm
::
::
:

Hi Steve,

Something seems odd. You mention that your short wave band does not work. The 35-Late radio has two short wave bands. Also, when I look up 35-late I find the schematics for two radios. One has 7 tubes, the other 5.

The alignment works for many radios. The injection point for tuning IFs is the mixer grid, which could be 2F7, 6A7 or 6A8.

Best Regards,

Bill

Hi Bill
The way I looked at the schematic for the 35(late)was the top schematic was for a model 47M and the bottom schematic was for the 35(late). The bottom schematic is the one that matches the chassis that I have. I have done the AM alignment but I'm not sure of the shortwave alignment.
Thanks
Steve
:

http://www.nostalgiaair.org/PagesByModel/863/M0012863.pdf.
vs
http://www.nostalgiaair.org/PagesByModel/869/M0012869.pdf

The schematic is different. However the alignment process is probably similar to the one given for model 56. I am sure Bill or someone can step through the differences. I see there is an OSC pad adjustment.

:After looking over the schematic for this radio I find that a model 36 is a six tube radio. This radio is a five tube radio. I’m fairly sure what I have is a model 35(late) chassis with the dial changed to the model 36 in a model 36 case. The model 35(late) schematic, chassis layout, and tube lineup matches the chassis I have. I need to replace the antenna coil as a mouse has chewed off some of the wires. I spliced it back together the best I could. The radio works on the AM band but not on the shortwave band. I’ve ordered some 4 lug Packard Bell antenna coils from Play Things Of The Past. Hopefully one of them will be correct. Did the factory sometimes use up the old chassis at the start of a model change? Does anyone have the alignment data for a 35(late)?
:Thanks
:Steve
:
:
::Thanks for the information. As soon as I change the capacitors I try your alignment procedure.
::Thanks
::Steve
::
:::Hi Steve,
::: To align the IFs set your signal generator to 460 KHz, modulation on. Turn the band switch to Short wave and to a place on the dial without signal.
::: Inject the modulated 460KHz from the signal generator on to the grid of the 2F7, ground to chassis. The modulated signal should be heard from the speaker. The volume control should be about 1/4 of full range. Adjust the signal generator so the sound is at a comfortable level.
::: Attach an AC meter to the speaker terminals. Adjust the IFs for maximum signal. As you tune the IFs keep cutting back on the signal generator signal level so the sound does not get too loud. This is not just to be easy on your ears, but it also prevents AGC action from messing up the alignment.
:::
::: Once you have that done the front end can be aligned on each band. The two 35 pF capacitors below the 2F7 adjust where stations come in on the dial, one for short wave the other for AM, standard broadcast. Adjust these so stations come in at the proper point. A good point for AM is 14ooKHz, for Short Wave, try 12MHz.
::: After that adjust the two 35pF capacitors above the 2F7 for peak. FOr AM a good point is around 600KHz. For Short wave I would try around 7MHz.
:::
::: If stations come in with birdies, it usually means the IF is oscillating. You would then need to detune the IF. On each If transformer turn one screw by 1/8 clockwise, the other by 1/8 turn counter clockwise. That should take the birdie out.
:::
:::Best Regards,
:::
:::Bill Grimm
:::
:::
::
:

That is one nice and detailed piece of work! I am sure Steve will appreciate it.

Jeff

:
:

: : : : : : : :Sir Steve. . . . . : : : : :An initial referencing of the schematic for your set reveals it to just be of limited use in the FULL info actually needed for :the alignment of that set of yours. A quick check of the page before and after in the Red Ryders manual also reveals that :there was no further dedicated info that might have also been placed there, being solely relevant to the sets alignment :procedure. : : :A check of ALL of the other Plastered Bells also reveals only schematics being provided. : : :Therefore, I have made up a mark-up referencing of only half of the schematic, including only the relevant RF section :to the left side. : : :In that manner, the unit can be kept as a page width, but with quick referencing access being available. : : :In associating the initial points of interest with their mark-ups, initially, there will be the tuning condensers ANTENNA RF :section " A " [BLUE] and its companion the OSCILLATOR section " B " [RED]. : : :The " A " tuning condenser section performs the ANT tuning action with its associative " C " [YELLOW] BCB ANTENNA :coil /transformer and the " D " [AQUA] SW ANTENNA coil /transformer. : : :The " B " tuning condenser section performs the OSC tuning action with its associative " C " [YELLOW] BCB :OSCILLATOR coil /transformer and the " D " [AQUA] SW OSCILLATOR coil /transformer. : : :With that old of a set, one might suspect that they will be paired up as separate antenna mounted and oscillator :coils, but will be sharing their typical 1 in diameter coil forms. : : :You can differentiate between the ANTENNA BCB and SW portions by the BCB utilizing waaaaaay more turns in its :coil winding than the SW coil; also I would suspect the antenna link windings to be incorporating but a few turns, :wound atop the end /edge of each antenna coil winding. : : :On the oscillator it consist of a complete tuned secondary winding for the BCB function, but the SW portion is a tap off :with its fewer turns. : : :As per THEIR identification, we are seeing that the " E " [ORANGE] is the BCB OSCILLATOR secondary coil and the :" F " [GRAY] is the SW OSCILLATOR coil tap off point, with its fewer turns. : : : : :Now as per alignment, they have given you only four adjustments: : : :In the RF antenna section there is . . . : : :K . . .The BCB / SW ANTENNA RF trimmer which is a shared between bands adjustment and is peaked for reception :on SW with the set tuned to the 15-16 Mhz end of the band or on the BCB in the 1500-1600 Khz end of the band. : : :( ( (See NOTE X at very end.) ) ) : : : :G . . . The BCB and SW OSCILLATOR trimmer which is, also a shared adjustment and is adjusted for dial scale :calibration accuracy at the 15 Mhz end of the SW band, or 1500 Khz on the BCB band, as well as having decent reception. : : :J . . . The BCB and SW OSCILLATOR padder condenser, which compresses/expands/shifts the dial scale calibration, :to acquire accuracy at ~ the 8 Mhz lower end of the SW band or 800 Khz on the BCB. : : :(As for the radios dial scale calibration "accuracy", with its small scales and cramped frequency plots, none of the : : :units qualify as being into " four place micrometer / caliper " accuracies.) : : : :I.F. Alignment: : : :The BCB band would be the band to start with, and I see that Sir Bill G has come back with some rough alignment :procedure, so I might as well slip in a few extras between the lines. : : :Figuring that you have a RF sig generator on the IF alignment, I place the tuning condenser at its fully meshed :condition and place a jumper between the osc setions rotor and stator section to kill the local oscillator. :Then the modulated tone from the signal generator being set at ~ 460 Kc is then only having its output RF attenuator :being brought up only enough to be able to weakly hear its modulated tone in the speaker. : : :You can either initially go by ear or later tie in AC metering across the AF output transformer OR use a series isolative :.05 cap from the plate of the AF output and then meter the high level audio present there, as being referenced to ground. : : :Start with the final IF transformer II secondary winding and work forward and then follow up and replicate all over :again. If you then want a final hair splitting alignment acccuracy you then monitor the AVC buss with a VTVM or else, :marginally utilize a 20 kOhm sensitivity, or greater, VOM. : : :The voltage expected will be an incrementally rising NEGATIVE voltage as referenced against ground. The stronger :the radio station OR the alignment adjustment peaking, the greater will be the negative voltage reading. : : :And then . . if you want to enact an even greater, final " Cow pee 'de grass " upon the unit, note the 2 meg isolation/ : drop resistor located at the botttom of the secondary winding of the II I.F. transformer. You then shift your metering :point from that multipointed basic AVC buss [ GREEN] up to the top side of that 2 meg resistor [2 green dots] and take :a jumper lead and then ground the bottom side of that 2 meg resistor [1 green dot] . : : :That is then getting the frontal RF tubes running at maximum unthrottled gain. : : :You then bring down the input 460 signal to the point where you still just have just enough signal to get a workable :reading from and go thru the full setting of all of the IF adjustments again. : : :BCB adjustments: : : :1 . . . . . " K " ANT trimmer : : :Initially, I would expect " K " ANT BCB / SW trimmer for the BCB high end RF adjustment to be built right into the :tuning condenser antenna sections framework. : : :It is to be adjusted for the optimal reception of a signal coming in at ~ 1600Khz. : : :2 . . . . . " G " OSC trimmer : : :The " G " OSC BCB / SW trimmer sets the accuracy of a station near the high end 1600 Khz portion of the dial . :It is to be adjusted for the optimal dial accuracy of a signal coming in at ~ 1600Khz : : :3 . . . . ." H " OSC Padder : : :This padder condenser is placing its value in series with the OSC tuned circuitry and its adjusted value is able to either :compress or s t r e t c h out the dial scale logging, most noticably at the low end of the dial scale. : : :Pick out a station . . . or sig gen frequency . . . on the 600-800 range and then trim " H " until the dial scale agrees. :SINCE this can also effect the high end of the dial scale slightly, go back to G and see if it needs any slight correction. :Eventually the two adjustments should get overall dial "spread" calibration optimal. : : : : :Preps for SW adjustment: : : :This will be harder if you are depending upon a received off the air signal on that 6-18 Mhz spectrum as those :stations vary in their optimal reception times all across the times of day, along with a HEALTHY length of antenna :wire also being needed. A handy evaluation antenna is a 50 -100 ft extension cord all strung out and as high as possible, :with the male plug end providing connections for a clip lead. : : :Once you are sucessfull in the reception of SW stations you can then possibly scale back in ant length if possible, :as well as learning the time of day that certain frequencies come in. : : :I even experience SELECT TIMES OF THE DAY , that I am even able to receive our ultra accurate WWV frequency :standards . .of which the tic-tic-tic / plus time announcement on the minute, could be applicable on 10 and 15 Mhz :for this receivers band coverage. : : : One could also fill in with the additional CHU Canadian time/frequencies of 7.335 and 14.670 kHz . With that 7.335 :fitting in nicely with a low end of the SW band check point, and either of the 15 of WWV or the 14670 of CHU in :Ottowa, filling in fine for a high end of the band reference point. : : :SW adjustment: : : :Unfortunately, the SW adjustment controls are the VERY same ones that were used for the BCB, so go thru the SW :procedure as was done with the BCB. : : :With K used at about 15-16 Mhz : : :With G used at about 15-16 Mhz : : :With H used for checking of dial scale accuracy at about 6 Mhz.(7.335)p> :Now you will have to evaluate performance and decide if you are wanting to leave these controls optimized for SW :or for BCB if there is some disparity in the performance between the two bands. : : : : :ADJUNCT . . . F.Y.I : : :Should anyone else be taking in this info, one can do some SUPER alignment accuracy by merely :using their basic inlellegentia and BCB stations. : : : : :Worst case: : : :Back at the IF alignment procedure you can go thru the simplest possibility of setting the signal generator to the dial :point where you assume that it is hopefully / correctly designating 455(460) KHZ, usually being interpolated in between :some vague hash marks. : : : : :Intermediate case: : : :The stepping up to the necessity of having a frequency counter, to additionally confirm the REAL frequency output :of the signal generator setting. : : : : :Alternate case: : : :The use of a second working receiver to receive an AM station operating on 910(920) Kc and then the radiating of :the signal from the generator via a loose wire "aerial ", and then the tuning of the sig generator to 455(460) where you :will initially hear a decreasing tone and then a zero beat and then the reversal of the tone when passing past 455(460). : : :You move back to the point of the "silent" zero beat and then, by that procedure, you are confirming your signal gens :second harmonic is being EXACTLY in congruence with the 910(920)Khz broadcast standard, therefore your 455(460) Khz setting is RIGHT ON to 455(460). : : : :PRECISE 455(460) Khz direct I.F. alignment using a Broadcast station for the freq standard . . .NO signal generator required: : : : :You tune in to a BCB station that is operating on 910 Khz or(920 Khz for a 460 Khz IF).(Possibly, nite time reception will be required . . .wherever and whenever a 910(920) Khz stations reception is possible.) : : You then initially trim in the set to be aligned by using its tuning condenser in setting to the :station, such that the reception is at its very strongest and then leave it placed at that setting. :If you will now tune in the II and I I.F.'s using the afore mentioned first Tune II then Tune I sequence, you will find :them now peaking , by virtue of 455(460) Khz being a 1/2 sub harmonic of 910 (920) Khz. : : :The same, further I.F. alignment ENHANCEMENT, is also possible via the additional use of the metering the AVC buss, :for being able to see a tangible level differentiation. : : :When you are aligned up this way, you are within thousands of cycles of the tightly FCC regulated BCB's operational :frequency's margin of error. : : :In my location, I happen to be lucky to have a station that is operating locally on 910 so I am always set up for an easy and precise :alignment of a 455/456 I.F. strip. Just a bit of tuning in to the station and a bit of initial listening for a couple of :HAIL MARY's . . .being thrown about. . . ( Local Catholic Network afilliate)and I then know that I am tuned in to the right station. : : :As per the 455/456 auspices . . . well, I just say . . . Po-Tay-Toe----Puh-Tah-Toe /Tum-May-Toe----Tum-Mah-Toe. :I frankly think the 455 / 456 situation might have been one manufacturer coming out with a carbon copy of another :receiver, but then countering with, BUT my receiver is NOT the same, it is COMPLETELY different, see, my unit amplifies :the signal at 456 KC ! : : : : :ASIDE: : : :And an even rarer second situation I once experienced, in a hotel as a kid, that in the days of radio being THE entertainment. :I frequently would hear a brief squealing tone / whistle coming from our receiver. : : :(Which years later . . . after some Edd-ication . . . I then associated that noise with being a heterodyne effect on our receiver : from a close by neighbors sets local oscillator , {which must have been a real brute}, as he was scanning across the dial. ) : : :One specific night, there was the situation of the neighbors selection of a station, such that their receivers local :oscillator happened to "collide" just about on top of our received signal of Amos and Andy. :Nothing then was present but a low gutteral tone, disrupting most of the sets audio, fortunately the movement of the radio :revealed a certain position where that the tone was minimal. : : :Then . . . the station came rolling in again . . . . Wit a "Holy Mackeral 'deah Andy ", and the full shenanigans going back into play, :down at the Lodge of the Mystic Knights of the Sea. : : : : :NOTE X: : : :On this receivers design, it is quite limiting in its alignment capabilities, by virtue of the K ant trimmer having to serve :for BOTH the SW and BCB ANT coil adjustments. : : :Should you want to improve upon that aspect, you could open up the K trimmer on the set , to its very min capacitance :position. : : :Then you mount a separate 3-35 pf mica compression trimmer across each, the BCB and SW coils, that remedying :situation will then let you have optimal alignment adjustment potential of the separate switched in BCB and SW ANT :coils. : : : : : : : : :73's de Edd : : : :

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: : : :HALF-PAGE SCHEMATIC R.F. REFERENCING of the #35 51/64ths . . . PLASTERED BELL : : : : : : : : :

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:

: : : : : : : :Sir Steve. . . . . : : : : :An initial referencing of the schematic for your set reveals it to just be of limited use in the FULL info actually needed for :the alignment of that set of yours. A quick check of the page before and after in the Red Ryders manual also reveals that :there was no further dedicated info that might have also been placed there, being solely relevant to the sets alignment :procedure. : : :A check of ALL of the other Plastered Bells also reveals only schematics being provided. : : :Therefore, I have made up a mark-up referencing of only half of the schematic, including only the relevant RF section :to the left side. : : :In that manner, the unit can be kept as a page width, but with quick referencing access being available. : : :In associating the initial points of interest with their mark-ups, initially, there will be the tuning condensers ANTENNA RF :section " A " [BLUE] and its companion the OSCILLATOR section " B " [RED]. : : :The " A " tuning condenser section performs the ANT tuning action with its associative " C " [YELLOW] BCB ANTENNA :coil /transformer and the " D " [AQUA] SW ANTENNA coil /transformer. : : :The " B " tuning condenser section performs the OSC tuning action with its associative " C " [YELLOW] BCB :OSCILLATOR coil /transformer and the " D " [AQUA] SW OSCILLATOR coil /transformer. : : :With that old of a set, one might suspect that they will be paired up as separate antenna mounted and oscillator :coils, but will be sharing their typical 1 in diameter coil forms. : : :You can differentiate between the ANTENNA BCB and SW portions by the BCB utilizing waaaaaay more turns in its :coil winding than the SW coil; also I would suspect the antenna link windings to be incorporating but a few turns, :wound atop the end /edge of each antenna coil winding. : : :On the oscillator it consist of a complete tuned secondary winding for the BCB function, but the SW portion is a tap off :with its fewer turns. : : :As per THEIR identification, we are seeing that the " E " [ORANGE] is the BCB OSCILLATOR secondary coil and the :" F " [GRAY] is the SW OSCILLATOR coil tap off point, with its fewer turns. : : : : :Now as per alignment, they have given you only four adjustments: : : :In the RF antenna section there is . . . : : :K . . .The BCB / SW ANTENNA RF trimmer which is a shared between bands adjustment and is peaked for reception :on SW with the set tuned to the 15-16 Mhz end of the band or on the BCB in the 1500-1600 Khz end of the band. : : :( ( (See NOTE X at very end.) ) ) : : : :G . . . The BCB and SW OSCILLATOR trimmer which is, also a shared adjustment and is adjusted for dial scale :calibration accuracy at the 15 Mhz end of the SW band, or 1500 Khz on the BCB band, as well as having decent reception. : : :J . . . The BCB and SW OSCILLATOR padder condenser, which compresses/expands/shifts the dial scale calibration, :to acquire accuracy at ~ the 8 Mhz lower end of the SW band or 800 Khz on the BCB. : : :(As for the radios dial scale calibration "accuracy", with its small scales and cramped frequency plots, none of the : : :units qualify as being into " four place micrometer / caliper " accuracies.) : : : :I.F. Alignment: : : :The BCB band would be the band to start with, and I see that Sir Bill G has come back with some rough alignment :procedure, so I might as well slip in a few extras between the lines. : : :Figuring that you have a RF sig generator on the IF alignment, I place the tuning condenser at its fully meshed :condition and place a jumper between the osc setions rotor and stator section to kill the local oscillator. :Then the modulated tone from the signal generator being set at ~ 460 Kc is then only having its output RF attenuator :being brought up only enough to be able to weakly hear its modulated tone in the speaker. : : :You can either initially go by ear or later tie in AC metering across the AF output transformer OR use a series isolative :.05 cap from the plate of the AF output and then meter the high level audio present there, as being referenced to ground. : : :Start with the final IF transformer II secondary winding and work forward and then follow up and replicate all over :again. If you then want a final hair splitting alignment acccuracy you then monitor the AVC buss with a VTVM or else, :marginally utilize a 20 kOhm sensitivity, or greater, VOM. : : :The voltage expected will be an incrementally rising NEGATIVE voltage as referenced against ground. The stronger :the radio station OR the alignment adjustment peaking, the greater will be the negative voltage reading. : : :And then . . if you want to enact an even greater, final " Cow pee 'de grass " upon the unit, note the 2 meg isolation/ : drop resistor located at the botttom of the secondary winding of the II I.F. transformer. You then shift your metering :point from that multipointed basic AVC buss [ GREEN] up to the top side of that 2 meg resistor [2 green dots] and take :a jumper lead and then ground the bottom side of that 2 meg resistor [1 green dot] . : : :That is then getting the frontal RF tubes running at maximum unthrottled gain. : : :You then bring down the input 460 signal to the point where you still just have just enough signal to get a workable :reading from and go thru the full setting of all of the IF adjustments again. : : :BCB adjustments: : : :1 . . . . . " K " ANT trimmer : : :Initially, I would expect " K " ANT BCB / SW trimmer for the BCB high end RF adjustment to be built right into the :tuning condenser antenna sections framework. : : :It is to be adjusted for the optimal reception of a signal coming in at ~ 1600Khz. : : :2 . . . . . " G " OSC trimmer : : :The " G " OSC BCB / SW trimmer sets the accuracy of a station near the high end 1600 Khz portion of the dial . :It is to be adjusted for the optimal dial accuracy of a signal coming in at ~ 1600Khz : : :3 . . . . ." H " OSC Padder : : :This padder condenser is placing its value in series with the OSC tuned circuitry and its adjusted value is able to either :compress or s t r e t c h out the dial scale logging, most noticably at the low end of the dial scale. : : :Pick out a station . . . or sig gen frequency . . . on the 600-800 range and then trim " H " until the dial scale agrees. :SINCE this can also effect the high end of the dial scale slightly, go back to G and see if it needs any slight correction. :Eventually the two adjustments should get overall dial "spread" calibration optimal. : : : : :Preps for SW adjustment: : : :This will be harder if you are depending upon a received off the air signal on that 6-18 Mhz spectrum as those :stations vary in their optimal reception times all across the times of day, along with a HEALTHY length of antenna :wire also being needed. A handy evaluation antenna is a 50 -100 ft extension cord all strung out and as high as possible, :with the male plug end providing connections for a clip lead. : : :Once you are sucessfull in the reception of SW stations you can then possibly scale back in ant length if possible, :as well as learning the time of day that certain frequencies come in. : : :I even experience SELECT TIMES OF THE DAY , that I am even able to receive our ultra accurate WWV frequency :standards . .of which the tic-tic-tic / plus time announcement on the minute, could be applicable on 10 and 15 Mhz :for this receivers band coverage. : : : One could also fill in with the additional CHU Canadian time/frequencies of 7.335 and 14.670 kHz . With that 7.335 :fitting in nicely with a low end of the SW band check point, and either of the 15 of WWV or the 14670 of CHU in :Ottowa, filling in fine for a high end of the band reference point. : : :SW adjustment: : : :Unfortunately, the SW adjustment controls are the VERY same ones that were used for the BCB, so go thru the SW :procedure as was done with the BCB. : : :With K used at about 15-16 Mhz : : :With G used at about 15-16 Mhz : : :With H used for checking of dial scale accuracy at about 6 Mhz.(7.335)p> :Now you will have to evaluate performance and decide if you are wanting to leave these controls optimized for SW :or for BCB if there is some disparity in the performance between the two bands. : : : : :ADJUNCT . . . F.Y.I : : :Should anyone else be taking in this info, one can do some SUPER alignment accuracy by merely :using their basic inlellegentia and BCB stations. : : : : :Worst case: : : :Back at the IF alignment procedure you can go thru the simplest possibility of setting the signal generator to the dial :point where you assume that it is hopefully / correctly designating 455(460) KHZ, usually being interpolated in between :some vague hash marks. : : : : :Intermediate case: : : :The stepping up to the necessity of having a frequency counter, to additionally confirm the REAL frequency output :of the signal generator setting. : : : : :Alternate case: : : :The use of a second working receiver to receive an AM station operating on 910(920) Kc and then the radiating of :the signal from the generator via a loose wire "aerial ", and then the tuning of the sig generator to 455(460) where you :will initially hear a decreasing tone and then a zero beat and then the reversal of the tone when passing past 455(460). : : :You move back to the point of the "silent" zero beat and then, by that procedure, you are confirming your signal gens :second harmonic is being EXACTLY in congruence with the 910(920)Khz broadcast standard, therefore your 455(460) Khz setting is RIGHT ON to 455(460). : : : :PRECISE 455(460) Khz direct I.F. alignment using a Broadcast station for the freq standard . . .NO signal generator required: : : : :You tune in to a BCB station that is operating on 910 Khz or(920 Khz for a 460 Khz IF).(Possibly, nite time reception will be required . . .wherever and whenever a 910(920) Khz stations reception is possible.) : : You then initially trim in the set to be aligned by using its tuning condenser in setting to the :station, such that the reception is at its very strongest and then leave it placed at that setting. :If you will now tune in the II and I I.F.'s using the afore mentioned first Tune II then Tune I sequence, you will find :them now peaking , by virtue of 455(460) Khz being a 1/2 sub harmonic of 910 (920) Khz. : : :The same, further I.F. alignment ENHANCEMENT, is also possible via the additional use of the metering the AVC buss, :for being able to see a tangible level differentiation. : : :When you are aligned up this way, you are within thousands of cycles of the tightly FCC regulated BCB's operational :frequency's margin of error. : : :In my location, I happen to be lucky to have a station that is operating locally on 910 so I am always set up for an easy and precise :alignment of a 455/456 I.F. strip. Just a bit of tuning in to the station and a bit of initial listening for a couple of :HAIL MARY's . . .being thrown about. . . ( Local Catholic Network afilliate)and I then know that I am tuned in to the right station. : : :As per the 455/456 auspices . . . well, I just say . . . Po-Tay-Toe----Puh-Tah-Toe /Tum-May-Toe----Tum-Mah-Toe. :I frankly think the 455 / 456 situation might have been one manufacturer coming out with a carbon copy of another :receiver, but then countering with, BUT my receiver is NOT the same, it is COMPLETELY different, see, my unit amplifies :the signal at 456 KC ! : : : : :ASIDE: : : :And an even rarer second situation I once experienced, in a hotel as a kid, that in the days of radio being THE entertainment. :I frequently would hear a brief squealing tone / whistle coming from our receiver. : : :(Which years later . . . after some Edd-ication . . . I then associated that noise with being a heterodyne effect on our receiver : from a close by neighbors sets local oscillator , {which must have been a real brute}, as he was scanning across the dial. ) : : :One specific night, there was the situation of the neighbors selection of a station, such that their receivers local :oscillator happened to "collide" just about on top of our received signal of Amos and Andy. :Nothing then was present but a low gutteral tone, disrupting most of the sets audio, fortunately the movement of the radio :revealed a certain position where that the tone was minimal. : : :Then . . . the station came rolling in again . . . . Wit a "Holy Mackeral 'deah Andy ", and the full shenanigans going back into play, :down at the Lodge of the Mystic Knights of the Sea. : : : : :NOTE X: : : :On this receivers design, it is quite limiting in its alignment capabilities, by virtue of the K ant trimmer having to serve :for BOTH the SW and BCB ANT coil adjustments. : : :Should you want to improve upon that aspect, you could open up the K trimmer on the set , to its very min capacitance :position. : : :Then you mount a separate 3-35 pf mica compression trimmer across each, the BCB and SW coils, that remedying :situation will then let you have optimal alignment adjustment potential of the separate switched in BCB and SW ANT :coils. : : : : : : : : :73's de Edd : : : :

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: : : :HALF-PAGE SCHEMATIC R.F. REFERENCING of the #35 51/64ths . . . PLASTERED BELL : : : : : : : : :

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: : : : : : : :Sir Steve. . . . . : : : : :An initial referencing of the schematic for your set reveals it to just be of limited use in the FULL info actually needed for :the alignment of that set of yours. A quick check of the page before and after in the Red Ryders manual also reveals that :there was no further dedicated info that might have also been placed there, being solely relevant to the sets alignment :procedure. : : :A check of ALL of the other Plastered Bells also reveals only schematics being provided. : : :Therefore, I have made up a mark-up referencing of only half of the schematic, including only the relevant RF section :to the left side. : : :In that manner, the unit can be kept as a page width, but with quick referencing access being available. : : :In associating the initial points of interest with their mark-ups, initially, there will be the tuning condensers ANTENNA RF :section " A " [BLUE] and its companion the OSCILLATOR section " B " [RED]. : : :The " A " tuning condenser section performs the ANT tuning action with its associative " C " [YELLOW] BCB ANTENNA :coil /transformer and the " D " [AQUA] SW ANTENNA coil /transformer. : : :The " B " tuning condenser section performs the OSC tuning action with its associative " C " [YELLOW] BCB :OSCILLATOR coil /transformer and the " D " [AQUA] SW OSCILLATOR coil /transformer. : : :With that old of a set, one might suspect that they will be paired up as separate antenna mounted and oscillator :coils, but will be sharing their typical 1 in diameter coil forms. : : :You can differentiate between the ANTENNA BCB and SW portions by the BCB utilizing waaaaaay more turns in its :coil winding than the SW coil; also I would suspect the antenna link windings to be incorporating but a few turns, :wound atop the end /edge of each antenna coil winding. : : :On the oscillator it consist of a complete tuned secondary winding for the BCB function, but the SW portion is a tap off :with its fewer turns. : : :As per THEIR identification, we are seeing that the " E " [ORANGE] is the BCB OSCILLATOR secondary coil and the :" F " [GRAY] is the SW OSCILLATOR coil tap off point, with its fewer turns. : : : : :Now as per alignment, they have given you only four adjustments: : : :In the RF antenna section there is . . . : : :K . . .The BCB / SW ANTENNA RF trimmer which is a shared between bands adjustment and is peaked for reception :on SW with the set tuned to the 15-16 Mhz end of the band or on the BCB in the 1500-1600 Khz end of the band. : : :( ( (See NOTE X at very end.) ) ) : : : :G . . . The BCB and SW OSCILLATOR trimmer which is, also a shared adjustment and is adjusted for dial scale :calibration accuracy at the 15 Mhz end of the SW band, or 1500 Khz on the BCB band, as well as having decent reception. : : :J . . . The BCB and SW OSCILLATOR padder condenser, which compresses/expands/shifts the dial scale calibration, :to acquire accuracy at ~ the 8 Mhz lower end of the SW band or 800 Khz on the BCB. : : :(As for the radios dial scale calibration "accuracy", with its small scales and cramped frequency plots, none of the : : :units qualify as being into " four place micrometer / caliper " accuracies.) : : : :I.F. Alignment: : : :The BCB band would be the band to start with, and I see that Sir Bill G has come back with some rough alignment :procedure, so I might as well slip in a few extras between the lines. : : :Figuring that you have a RF sig generator on the IF alignment, I place the tuning condenser at its fully meshed :condition and place a jumper between the osc setions rotor and stator section to kill the local oscillator. :Then the modulated tone from the signal generator being set at ~ 460 Kc is then only having its output RF attenuator :being brought up only enough to be able to weakly hear its modulated tone in the speaker. : : :You can either initially go by ear or later tie in AC metering across the AF output transformer OR use a series isolative :.05 cap from the plate of the AF output and then meter the high level audio present there, as being referenced to ground. : : :Start with the final IF transformer II secondary winding and work forward and then follow up and replicate all over :again. If you then want a final hair splitting alignment acccuracy you then monitor the AVC buss with a VTVM or else, :marginally utilize a 20 kOhm sensitivity, or greater, VOM. : : :The voltage expected will be an incrementally rising NEGATIVE voltage as referenced against ground. The stronger :the radio station OR the alignment adjustment peaking, the greater will be the negative voltage reading. : : :And then . . if you want to enact an even greater, final " Cow pee 'de grass " upon the unit, note the 2 meg isolation/ : drop resistor located at the botttom of the secondary winding of the II I.F. transformer. You then shift your metering :point from that multipointed basic AVC buss [ GREEN] up to the top side of that 2 meg resistor [2 green dots] and take :a jumper lead and then ground the bottom side of that 2 meg resistor [1 green dot] . : : :That is then getting the frontal RF tubes running at maximum unthrottled gain. : : :You then bring down the input 460 signal to the point where you still just have just enough signal to get a workable :reading from and go thru the full setting of all of the IF adjustments again. : : :BCB adjustments: : : :1 . . . . . " K " ANT trimmer : : :Initially, I would expect " K " ANT BCB / SW trimmer for the BCB high end RF adjustment to be built right into the :tuning condenser antenna sections framework. : : :It is to be adjusted for the optimal reception of a signal coming in at ~ 1600Khz. : : :2 . . . . . " G " OSC trimmer : : :The " G " OSC BCB / SW trimmer sets the accuracy of a station near the high end 1600 Khz portion of the dial . :It is to be adjusted for the optimal dial accuracy of a signal coming in at ~ 1600Khz : : :3 . . . . ." H " OSC Padder : : :This padder condenser is placing its value in series with the OSC tuned circuitry and its adjusted value is able to either :compress or s t r e t c h out the dial scale logging, most noticably at the low end of the dial scale. : : :Pick out a station . . . or sig gen frequency . . . on the 600-800 range and then trim " H " until the dial scale agrees. :SINCE this can also effect the high end of the dial scale slightly, go back to G and see if it needs any slight correction. :Eventually the two adjustments should get overall dial "spread" calibration optimal. : : : : :Preps for SW adjustment: : : :This will be harder if you are depending upon a received off the air signal on that 6-18 Mhz spectrum as those :stations vary in their optimal reception times all across the times of day, along with a HEALTHY length of antenna :wire also being needed. A handy evaluation antenna is a 50 -100 ft extension cord all strung out and as high as possible, :with the male plug end providing connections for a clip lead. : : :Once you are sucessfull in the reception of SW stations you can then possibly scale back in ant length if possible, :as well as learning the time of day that certain frequencies come in. : : :I even experience SELECT TIMES OF THE DAY , that I am even able to receive our ultra accurate WWV frequency :standards . .of which the tic-tic-tic / plus time announcement on the minute, could be applicable on 10 and 15 Mhz :for this receivers band coverage. : : : One could also fill in with the additional CHU Canadian time/frequencies of 7.335 and 14.670 kHz . With that 7.335 :fitting in nicely with a low end of the SW band check point, and either of the 15 of WWV or the 14670 of CHU in :Ottowa, filling in fine for a high end of the band reference point. : : :SW adjustment: : : :Unfortunately, the SW adjustment controls are the VERY same ones that were used for the BCB, so go thru the SW :procedure as was done with the BCB. : : :With K used at about 15-16 Mhz : : :With G used at about 15-16 Mhz : : :With H used for checking of dial scale accuracy at about 6 Mhz.(7.335)p> :Now you will have to evaluate performance and decide if you are wanting to leave these controls optimized for SW :or for BCB if there is some disparity in the performance between the two bands. : : : : :ADJUNCT . . . F.Y.I : : :Should anyone else be taking in this info, one can do some SUPER alignment accuracy by merely :using their basic inlellegentia and BCB stations. : : : : :Worst case: : : :Back at the IF alignment procedure you can go thru the simplest possibility of setting the signal generator to the dial :point where you assume that it is hopefully / correctly designating 455(460) KHZ, usually being interpolated in between :some vague hash marks. : : : : :Intermediate case: : : :The stepping up to the necessity of having a frequency counter, to additionally confirm the REAL frequency output :of the signal generator setting. : : : : :Alternate case: : : :The use of a second working receiver to receive an AM station operating on 910(920) Kc and then the radiating of :the signal from the generator via a loose wire "aerial ", and then the tuning of the sig generator to 455(460) where you :will initially hear a decreasing tone and then a zero beat and then the reversal of the tone when passing past 455(460). : : :You move back to the point of the "silent" zero beat and then, by that procedure, you are confirming your signal gens :second harmonic is being EXACTLY in congruence with the 910(920)Khz broadcast standard, therefore your 455(460) Khz setting is RIGHT ON to 455(460). : : : :PRECISE 455(460) Khz direct I.F. alignment using a Broadcast station for the freq standard . . .NO signal generator required: : : : :You tune in to a BCB station that is operating on 910 Khz or(920 Khz for a 460 Khz IF).(Possibly, nite time reception will be required . . .wherever and whenever a 910(920) Khz stations reception is possible.) : : You then initially trim in the set to be aligned by using its tuning condenser in setting to the :station, such that the reception is at its very strongest and then leave it placed at that setting. :If you will now tune in the II and I I.F.'s using the afore mentioned first Tune II then Tune I sequence, you will find :them now peaking , by virtue of 455(460) Khz being a 1/2 sub harmonic of 910 (920) Khz. : : :The same, further I.F. alignment ENHANCEMENT, is also possible via the additional use of the metering the AVC buss, :for being able to see a tangible level differentiation. : : :When you are aligned up this way, you are within thousands of cycles of the tightly FCC regulated BCB's operational :frequency's margin of error. : : :In my location, I happen to be lucky to have a station that is operating locally on 910 so I am always set up for an easy and precise :alignment of a 455/456 I.F. strip. Just a bit of tuning in to the station and a bit of initial listening for a couple of :HAIL MARY's . . .being thrown about. . . ( Local Catholic Network afilliate)and I then know that I am tuned in to the right station. : : :As per the 455/456 auspices . . . well, I just say . . . Po-Tay-Toe----Puh-Tah-Toe /Tum-May-Toe----Tum-Mah-Toe. :I frankly think the 455 / 456 situation might have been one manufacturer coming out with a carbon copy of another :receiver, but then countering with, BUT my receiver is NOT the same, it is COMPLETELY different, see, my unit amplifies :the signal at 456 KC ! : : : : :ASIDE: : : :And an even rarer second situation I once experienced, in a hotel as a kid, that in the days of radio being THE entertainment. :I frequently would hear a brief squealing tone / whistle coming from our receiver. : : :(Which years later . . . after some Edd-ication . . . I then associated that noise with being a heterodyne effect on our receiver : from a close by neighbors sets local oscillator , {which must have been a real brute}, as he was scanning across the dial. ) : : :One specific night, there was the situation of the neighbors selection of a station, such that their receivers local :oscillator happened to "collide" just about on top of our received signal of Amos and Andy. :Nothing then was present but a low gutteral tone, disrupting most of the sets audio, fortunately the movement of the radio :revealed a certain position where that the tone was minimal. : : :Then . . . the station came rolling in again . . . . Wit a "Holy Mackeral 'deah Andy ", and the full shenanigans going back into play, :down at the Lodge of the Mystic Knights of the Sea. : : : : :NOTE X: : : :On this receivers design, it is quite limiting in its alignment capabilities, by virtue of the K ant trimmer having to serve :for BOTH the SW and BCB ANT coil adjustments. : : :Should you want to improve upon that aspect, you could open up the K trimmer on the set , to its very min capacitance :position. : : :Then you mount a separate 3-35 pf mica compression trimmer across each, the BCB and SW coils, that remedying :situation will then let you have optimal alignment adjustment potential of the separate switched in BCB and SW ANT :coils. : : : : : : : : :73's de Edd : : : :

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: : : :HALF-PAGE SCHEMATIC R.F. REFERENCING of the #35 51/64ths . . . PLASTERED BELL : : : : : : : : :

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: : : : : : : :Sir Steve . . . . . : : : :Ah . . yes . . GOOD SHOW so far ! : : :In striving on, for yet greater perfection, now lets consider the "botor moating" aspect of its operation, attacking it in three manners. : : :Initially I don't know if electrolytics are new and their transition with time to having taken on unacceptable ESR levels. : : :Even, your having used units with less than effective attributes in their replacements. : : :Sooo initially shunt the electrolytic filters one at a time with an additional 5-10 ufd unit one at a time. : : :In this manner . . . . have the set doing its bad thing by the tuning in to SW and tuning condenser mesh until that condition onsets. : : :Power down the set and pull out a 5-10 ufd tubular electrolytic and jumper clip connect across one of the power electrolytics :and then turn on the set and let B+ develop and have the set working to see if there was any affectation, specifically the complete loss of the problem or a rate of speed change of the problem. : : :If any doubt on the speed change , leave powered up and break one INSULATED clip connetion to the electrolytic and then listen and touch the connection back to see if there was any change. : : :(In that manner there will be no initial sparky-sparky due to the electrolytic having already been at full charge potential.) : : :If no difference, power down and move the same electrolytic regalia over to the other electrolytic and test in the same manner. : : :That covers the low Z aspect of electrolytic decoupling, so now lets move on the effective RF decoupling aspects of those units. : : :To do that we need to rely upon the ultra low ESR characteristics and superb RF decoupling and bypassing that are exhibited by use of the common disc ceramic type of capacitor, when being utilized in the RF spectrum. : : :So, locate yourself an .01 ufd (or higher ) capacitance disc ceramic capacitor, if you just happen to have one of the proper HV rating, as is to be found on the sets B+ line. : : :In this testing I usually just hand grip the cap between thumb and forefinger to be able to manipulate its 2 connections. This is one time when a clipped lead unit will suffice, as it merely has to bridge between the test point and ground. If YOU are a bit antsy in finger handling the insulated ceramic casing, put on your glove . . . . . toboggin and scarf. : : :This time, have the set doing its BAAAAD thing and then bypass each filter condenser with that additional RF bypassing element to see if there is a change in the situation. : : :If no correction of the fault, then lets move further on the bypass testing aspect . . .since we are on a ro l l l l l l. : : :Now consult the schematic and look at your two IF transformers and see that on their primaries that they are getting connected to the plates of the mixer and IF amplifier . . . that the low end of the windings that recieve the B+ . . . are dependent upon the somewhat remoted position of the elecrtolytics for their RF bypassing. : : :Additianally take note of the screens of those 2 tubes and that they are receiving their subbed down B+ level thru that adjunct 15K resistor and then sharing a common decoupling capacitor in the form of that .1 ufd COMMON paper capacitor. : : :Lets get the set powered up again and doing its" thang" and then move our ceramic test capacitor in to explore 4 test positions. : : :The first two would be the sequential placing of the cap RIGHT at the screen grid connection of each of the socket pins of the mixer tube and then the IF tube to ground . . . and the bare chassis itself should suffice unless oxidized over. : : :Any cessation, or decline of the effect in that manner ? : : :Next move to the testing of the B+ supply into the IF transformers, somehow in that old of a receiver I visualise cotton covered wires coming out of the transformers versus the having of dedicated terminal lugs, as were on newer units. : : :BUT that wire is of limited length, so do your capacitor bypassing of that wire to ground , at the first connection point that it has to make. you will be doing the same on the other IF transformers B+ supply. : : :Have we had any effect ? : : : : :Shifting now into another mode: : : :The next aspect would be the checking of the 4 IF trimmer capacitor adjustments, you might already have some "tic" mark references made on the slot of a trimmer adjustment screw heads slot to the fixed housing shroud beside it. If not, do so now on all 4. : : :Th e e e n you fire up the set and have it BAAAAD and proceed to test each individual adjustment a wee bit by the variance of each trimmer 1/8 of a turn in both CW and then CCW direction FROM their initial positions. Moving the adjustment back before moving on to another . If this had effect on one , try the touchy one 1/4 turn CW -CCW . : : :Standing by for feedback . . . . . : : : : : : : : :73's de Edd : : : :

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:Does your 6D6 have a shield on it? I think it should have one if it does not. Be sure the shield has a good ground to the chassis. An Emerson BJ-200 did kind of the same thing. I did solder the shield to a lug on the chassis. Works perfect now.
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: : : : : : : :Sir Steve . . . . . : : : :Ah . . yes . . GOOD SHOW so far ! : : :In striving on, for yet greater perfection, now lets consider the "botor moating" aspect of its operation, attacking it in three manners. : : :Initially I don't know if electrolytics are new and their transition with time to having taken on unacceptable ESR levels. : : :Even, your having used units with less than effective attributes in their replacements. : : :Sooo initially shunt the electrolytic filters one at a time with an additional 5-10 ufd unit one at a time. : : :In this manner . . . . have the set doing its bad thing by the tuning in to SW and tuning condenser mesh until that condition onsets. : : :Power down the set and pull out a 5-10 ufd tubular electrolytic and jumper clip connect across one of the power electrolytics :and then turn on the set and let B+ develop and have the set working to see if there was any affectation, specifically the complete loss of the problem or a rate of speed change of the problem. : : :If any doubt on the speed change , leave powered up and break one INSULATED clip connetion to the electrolytic and then listen and touch the connection back to see if there was any change. : : :(In that manner there will be no initial sparky-sparky due to the electrolytic having already been at full charge potential.) : : :If no difference, power down and move the same electrolytic regalia over to the other electrolytic and test in the same manner. : : :That covers the low Z aspect of electrolytic decoupling, so now lets move on the effective RF decoupling aspects of those units. : : :To do that we need to rely upon the ultra low ESR characteristics and superb RF decoupling and bypassing that are exhibited by use of the common disc ceramic type of capacitor, when being utilized in the RF spectrum. : : :So, locate yourself an .01 ufd (or higher ) capacitance disc ceramic capacitor, if you just happen to have one of the proper HV rating, as is to be found on the sets B+ line. : : :In this testing I usually just hand grip the cap between thumb and forefinger to be able to manipulate its 2 connections. This is one time when a clipped lead unit will suffice, as it merely has to bridge between the test point and ground. If YOU are a bit antsy in finger handling the insulated ceramic casing, put on your glove . . . . . toboggin and scarf. : : :This time, have the set doing its BAAAAD thing and then bypass each filter condenser with that additional RF bypassing element to see if there is a change in the situation. : : :If no correction of the fault, then lets move further on the bypass testing aspect . . .since we are on a ro l l l l l l. : : :Now consult the schematic and look at your two IF transformers and see that on their primaries that they are getting connected to the plates of the mixer and IF amplifier . . . that the low end of the windings that recieve the B+ . . . are dependent upon the somewhat remoted position of the elecrtolytics for their RF bypassing. : : :Additianally take note of the screens of those 2 tubes and that they are receiving their subbed down B+ level thru that adjunct 15K resistor and then sharing a common decoupling capacitor in the form of that .1 ufd COMMON paper capacitor. : : :Lets get the set powered up again and doing its" thang" and then move our ceramic test capacitor in to explore 4 test positions. : : :The first two would be the sequential placing of the cap RIGHT at the screen grid connection of each of the socket pins of the mixer tube and then the IF tube to ground . . . and the bare chassis itself should suffice unless oxidized over. : : :Any cessation, or decline of the effect in that manner ? : : :Next move to the testing of the B+ supply into the IF transformers, somehow in that old of a receiver I visualise cotton covered wires coming out of the transformers versus the having of dedicated terminal lugs, as were on newer units. : : :BUT that wire is of limited length, so do your capacitor bypassing of that wire to ground , at the first connection point that it has to make. you will be doing the same on the other IF transformers B+ supply. : : :Have we had any effect ? : : : : :Shifting now into another mode: : : :The next aspect would be the checking of the 4 IF trimmer capacitor adjustments, you might already have some "tic" mark references made on the slot of a trimmer adjustment screw heads slot to the fixed housing shroud beside it. If not, do so now on all 4. : : :Th e e e n you fire up the set and have it BAAAAD and proceed to test each individual adjustment a wee bit by the variance of each trimmer 1/8 of a turn in both CW and then CCW direction FROM their initial positions. Moving the adjustment back before moving on to another . If this had effect on one , try the touchy one 1/4 turn CW -CCW . : : :Standing by for feedback . . . . . : : : : : : : : :73's de Edd : : : :

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Sir Steve . . . . . Looks like I got all tied up, only able to come back until just now, but you have advanced forward, almost to completion. By order of procedure, I just initially wanted to positively confirm that the oscillation /feedback path cause was not due to interstage feedback in a low frequency mode thru the electrolytics of the set or in the RF mode thru the mentioned RF bypassing points. You could never work around one of those particular conditions unless they are initially rooted out. The next step in order was the "borrowing" of one of "mammas" rubber gloves and a carresssing and fondling of the wiring and components used in the Mixer and IF stages . . to see if a shift in that problematic low pulsation frequency was caused in any one area. And . . . it looks like that 6D6's wiring should have certainly sounded off. Now, that thickness of a rubber / vinyl glove is about right . . . as a surgical glove, I certainly would be squeamish about in 2-300V areas. While, a linemans glove is a bit overkill, and you KNOWS I would not steer you towards Sir Lancelots chain mail mesh glove. Hi Hi . Once finding the touchy area I usually then shift to using a plastic rod or orange stick for moving wires, etc.about. And yes, in that IF area, I have certainly found my share of tube shield grounding integrity on those old S profile tubes. With that 1st grid connection being on top, I can certainly hope that the set happened to NOT have the grid caps wiring having to run down ALL the way to the chassis and then be routed a bit of distance under there until FINALLY making its circuit connection. I have certainly solved problems at times by the mechanical replication of the procedure that some sets use by having the Mixer outputs lead passing thru a hole in the top of the 1st IF transformer can, such that the lead exposure is absolute minimal until connecting to the 1st grid of the IF tube. Looks like you are home safe now in the spurious oscillations department. Only two further optimizing operations things that I can think of now, one would be the use of the two separate trimmer capacitors mentioned, them being placed across the Antenna coil windings of the BCB and SW bands. The other aspect would be the assurance of a precise and optimal 460 Khz output across the most of the dial spread as is possible. Not wanting to overload you on the the info situation on the initial adjustments of the local oscillator, you might now check the adjustments of the oscillator padder to see if a slight variance might up the sets sensitivity performanece, yet a bit more. With thatadjustment having to serve for both BCB . . . AND . . . SW modes, its your call on the band of desired optimization. That adjustment is the final check out of the optimum tracking of the tuning condenser in the producing of an optimal 460 sig out to the IF stage. I initially depicted the affectation of each of the TRIMMER and the PADDER of the Oscillator adjustments as being relevant to dial scale calibration rough in. A misadjusted PADDER can REALLY throw things askew, but you apparently are tuned in pretty close now. What you might further explore now is to tune in to either a marginally weak signal at the low end of the BCB . .or SW band, be it either from your signal generator or a stable strength, received off the air radio signal. The frequency of interest would be at about a 2/3 from being fully meshed condition of the tuning condensers plates, which usually is being at ~ 600 Khz. The idea now is to see if the sensitivity can be upped in that region of the BCB by confirming if the "460" IF output is being optimal in its setting (a.k.a. tracking). To ascertain that, one takes an aural note of the strength of that incoming signal , then initially place a "tic" mark aside the slot in the padder condenser so that the starting point can be referenced back to in the future. Start your tuning from being tuned RIGHT ON to that signal, to first tuning just above the signal till losing it and then back onto the station and off of the station to a lower frequency and then losing it and then RAPIDLY and repetetively keep repeating that tuning action procedure. ASSIST . . . in some situations where there is minimal "gear" loading of the dial drive mechanism, it is easier to just grab ahold of the tuning condenser's pulley drum and rotate it, instead of having the the slower gear down effect that would experienced in using the tuning knob proper for trying to accomplish that rapid of a back and forth, repetetive tuning action. Then you start a very slow movement of the padder adjustment in one direction, all of the time while rapidly varing the tuning condenser. At some point you will realize " Hey, that signal is starting to get weaker ! You then tic mark the padder condensers position. Then you bring the padder setting back to your starting mark and start the same procedure, but with the moving of the padder in the other direction. At the pount where the reception level has diminished a like amount, you then make another tic mark for that adjustment setting and then end up interpolating between the two padder positions extremes and making the placement of the final padder setting to be half way between those markings. That's it, with the exception of going back to the ANTENNA trimmer adjustment again and peaking it at the high end of the band. The only other refinement would be the use of the separate padders across each of the BCB and SW antenna coil propers. I see that some surplus . .cheep . . . units are still available at: > > > CHEEP VARIABLE TRIMMER CAPACITORS . . Ltd < < < Listed as his 1107-022 at 40 cents a copy and its 5-85 pf range, with the lower 5pf certainly being in order, but with the 85 value being quite a bit on up from the usual 35 pf, but just don't expect the need to EVER compress it on up to that full 85 value. Thassit . . . . 73's de Edd

:Hi Edd
:I had this old Packard Bell work great except that I had to place the grid wire on the 6D6 on the backside of the tube to stop the motor boating. Yesterday I received the antenna coils I had ordered. One of the coils looked correct for this radio so I removed old coil which I had tried to repair and installed the new coil. I went through your alignment procedure again and now no more motor boating no matter where I move the grid wire. The SW band also has a little more volume. The BCB still works great. I now consider this radio done. Thanks Edd and everyone else that helped me restore this radio.
:Steve
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:: :: :: :: :: :: :: ::Sir Steve . . . . . :: :: :: ::Ah . . yes . . GOOD SHOW so far ! :: :: ::In striving on, for yet greater perfection, now lets consider the "botor moating" aspect of its operation, attacking it in three manners. :: :: ::Initially I don't know if electrolytics are new and their transition with time to having taken on unacceptable ESR levels. :: :: ::Even, your having used units with less than effective attributes in their replacements. :: :: ::Sooo initially shunt the electrolytic filters one at a time with an additional 5-10 ufd unit one at a time. :: :: ::In this manner . . . . have the set doing its bad thing by the tuning in to SW and tuning condenser mesh until that condition onsets. :: :: ::Power down the set and pull out a 5-10 ufd tubular electrolytic and jumper clip connect across one of the power electrolytics ::and then turn on the set and let B+ develop and have the set working to see if there was any affectation, specifically the complete loss of the problem or a rate of speed change of the problem. :: :: ::If any doubt on the speed change , leave powered up and break one INSULATED clip connetion to the electrolytic and then listen and touch the connection back to see if there was any change. :: :: ::(In that manner there will be no initial sparky-sparky due to the electrolytic having already been at full charge potential.) :: :: ::If no difference, power down and move the same electrolytic regalia over to the other electrolytic and test in the same manner. :: :: ::That covers the low Z aspect of electrolytic decoupling, so now lets move on the effective RF decoupling aspects of those units. :: :: ::To do that we need to rely upon the ultra low ESR characteristics and superb RF decoupling and bypassing that are exhibited by use of the common disc ceramic type of capacitor, when being utilized in the RF spectrum. :: :: ::So, locate yourself an .01 ufd (or higher ) capacitance disc ceramic capacitor, if you just happen to have one of the proper HV rating, as is to be found on the sets B+ line. :: :: ::In this testing I usually just hand grip the cap between thumb and forefinger to be able to manipulate its 2 connections. This is one time when a clipped lead unit will suffice, as it merely has to bridge between the test point and ground. If YOU are a bit antsy in finger handling the insulated ceramic casing, put on your glove . . . . . toboggin and scarf. :: :: ::This time, have the set doing its BAAAAD thing and then bypass each filter condenser with that additional RF bypassing element to see if there is a change in the situation. :: :: ::If no correction of the fault, then lets move further on the bypass testing aspect . . .since we are on a ro l l l l l l. :: :: ::Now consult the schematic and look at your two IF transformers and see that on their primaries that they are getting connected to the plates of the mixer and IF amplifier . . . that the low end of the windings that recieve the B+ . . . are dependent upon the somewhat remoted position of the elecrtolytics for their RF bypassing. :: :: ::Additianally take note of the screens of those 2 tubes and that they are receiving their subbed down B+ level thru that adjunct 15K resistor and then sharing a common decoupling capacitor in the form of that .1 ufd COMMON paper capacitor. :: :: ::Lets get the set powered up again and doing its" thang" and then move our ceramic test capacitor in to explore 4 test positions. :: :: ::The first two would be the sequential placing of the cap RIGHT at the screen grid connection of each of the socket pins of the mixer tube and then the IF tube to ground . . . and the bare chassis itself should suffice unless oxidized over. :: :: ::Any cessation, or decline of the effect in that manner ? :: :: ::Next move to the testing of the B+ supply into the IF transformers, somehow in that old of a receiver I visualise cotton covered wires coming out of the transformers versus the having of dedicated terminal lugs, as were on newer units. :: :: ::BUT that wire is of limited length, so do your capacitor bypassing of that wire to ground , at the first connection point that it has to make. you will be doing the same on the other IF transformers B+ supply. :: :: ::Have we had any effect ? :: :: :: :: ::Shifting now into another mode: :: :: ::The next aspect would be the checking of the 4 IF trimmer capacitor adjustments, you might already have some "tic" mark references made on the slot of a trimmer adjustment screw heads slot to the fixed housing shroud beside it. If not, do so now on all 4. :: :: ::Th e e e n you fire up the set and have it BAAAAD and proceed to test each individual adjustment a wee bit by the variance of each trimmer 1/8 of a turn in both CW and then CCW direction FROM their initial positions. Moving the adjustment back before moving on to another . If this had effect on one , try the touchy one 1/4 turn CW -CCW . :: :: ::Standing by for feedback . . . . . :: :: :: :: :: :: :: :: ::73's de Edd :: :: :: ::

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