thanks for the help
Tom
Do you have the same problem on shortwave as well as broadcast?
Check the resistances of the antenna xfmr windings and make sure something isn't open. Check out the antenna ckt between the antenna terminal and the grid of the 6A8, including the contacts on the bandswitch. Lift a lead on the cap #3 and measure the resistance across it - should be infinite.
Doug
:I have been working on a Philco 37-61 and it does not perform like I think it should. when alignment is done I have a problem adjusting the ant. transformer compensating cap. It needs to be adjusted ALL the way out to get the strongest signal. This can't be right can it? It needs to be out untill no spring tension is on the screw. When I connect the antenna the the grid of the first tube 6A8G I get very good performance. If you look at the schematic the cap I'm adjusting is #3
:thanks for the help
:Tom
tom
:Tom: Here is the schematic: http://www.nostalgiaair.org/PagesByModel/208/M0013208.pdf
:
:Do you have the same problem on shortwave as well as broadcast?
:
:Check the resistances of the antenna xfmr windings and make sure something isn't open. Check out the antenna ckt between the antenna terminal and the grid of the 6A8, including the contacts on the bandswitch. Lift a lead on the cap #3 and measure the resistance across it - should be infinite.
:Doug
:
::I have been working on a Philco 37-61 and it does not perform like I think it should. when alignment is done I have a problem adjusting the ant. transformer compensating cap. It needs to be adjusted ALL the way out to get the strongest signal. This can't be right can it? It needs to be out untill no spring tension is on the screw. When I connect the antenna the the grid of the first tube 6A8G I get very good performance. If you look at the schematic the cap I'm adjusting is #3
::thanks for the help
::Tom
:Doug, Thanks for the responce. No I do not have the same problem on S.W. Yes ,I have the copy of the schematic, I checked all the restance of the coil ,primary and secondary... tried new tube no help, After just turing screws, not following the alignment instructions I got the dial to track better and now the problem is mainly down at 800kc and lower.. This means that no improvment with antenna at grid of 6a8 than with antenna at the correct terminal, but at lower than about 800kc it will make a big differance. antenna trimmer screw is still all the way out. I will check the grid lead resistance and get back shortly
:tom
:
::Tom: Here is the schematic: http://www.nostalgiaair.org/PagesByModel/208/M0013208.pdf
::
::Do you have the same problem on shortwave as well as broadcast?
::
::Check the resistances of the antenna xfmr windings and make sure something isn't open. Check out the antenna ckt between the antenna terminal and the grid of the 6A8, including the contacts on the bandswitch. Lift a lead on the cap #3 and measure the resistance across it - should be infinite.
::Doug
::
:::I have been working on a Philco 37-61 and it does not perform like I think it should. when alignment is done I have a problem adjusting the ant. transformer compensating cap. It needs to be adjusted ALL the way out to get the strongest signal. This can't be right can it? It needs to be out untill no spring tension is on the screw. When I connect the antenna the the grid of the first tube 6A8G I get very good performance. If you look at the schematic the cap I'm adjusting is #3
:::thanks for the help
:::Tom
Tom
:Grid checked out fine 0 restance back through bandswitch etc.. max restance from grid to ground
:
:
:
:
::Doug, Thanks for the responce. No I do not have the same problem on S.W. Yes ,I have the copy of the schematic, I checked all the restance of the coil ,primary and secondary... tried new tube no help, After just turing screws, not following the alignment instructions I got the dial to track better and now the problem is mainly down at 800kc and lower.. This means that no improvment with antenna at grid of 6a8 than with antenna at the correct terminal, but at lower than about 800kc it will make a big differance. antenna trimmer screw is still all the way out. I will check the grid lead resistance and get back shortly
::tom
::
:::Tom: Here is the schematic: http://www.nostalgiaair.org/PagesByModel/208/M0013208.pdf
:::
:::Do you have the same problem on shortwave as well as broadcast?
:::
:::Check the resistances of the antenna xfmr windings and make sure something isn't open. Check out the antenna ckt between the antenna terminal and the grid of the 6A8, including the contacts on the bandswitch. Lift a lead on the cap #3 and measure the resistance across it - should be infinite.
:::Doug
:::
::::I have been working on a Philco 37-61 and it does not perform like I think it should. when alignment is done I have a problem adjusting the ant. transformer compensating cap. It needs to be adjusted ALL the way out to get the strongest signal. This can't be right can it? It needs to be out untill no spring tension is on the screw. When I connect the antenna the the grid of the first tube 6A8G I get very good performance. If you look at the schematic the cap I'm adjusting is #3
::::thanks for the help
::::Tom
With your forthcoming info, sounds like the BCB ant coil is wanting to be of less inductive in its value if #3 trimmer is wanting to be set to that low of a capacitive value to enhance low BCB reception. OR. . .the possibility of the I.F.'s not collectively being aligned closely enough to
acquire the precise 470 kc tracking differential.
Hows about trying a check on them, by evaluating with a minimum input condition, akin to such as you would be subjecting them to in the reception of a weak DX BCB station.
This is considering the possibility that the initial alignment RF input level had swamped out the adjustments somewhat, making the I.F. peaking a bit broad in its adjustment, and wavering from tuned circuit to tuned circuit in the I.F. strip.
What I do is confirm that my un modulated signal generator is right on by using a freq counter or use of its reception by a Digital receiver or the poor man's option of a simple tuning in of the sig gen to ~470 and use another receiver and tune in to a BCB station on 940 Kc and listen for the heterodyning of the 2nd harmonic of the 470 sig gen signal and trim in the sig gen freq to get a zero beat.
My RG coax from the sig gen is terminated with an alligator clip so I just clip on to any cotton / plastic wiring on any portion of the common wiring connections between the ant coil, tuning condenser stator of the RF section or even the wiring running up to the mixer grid cap. That gets a weak "gimmick" coupled level of RF signal into the front end.
The 400 Cycle mod is then turned on and the tuning condenser swung to the max open position and then the RF level of the sig generator is brought up until the signals tone can just be heard.
Initially, the final IF winding at the detector stage is peaked and then the sequential IF tuned circuits working towards the plate of the mixer are peaked. That should be sufficient, unless the gain and sound level has come up enough such that you might want to do again using the minimum level of sig gen mod RF possible.
My logic is to replicate the strips same weak levels as is experienced on trying to pull in weak DX BCB stations.
Then, with your strip aligned in that manner, go back and do the RF alignment of that RF trimmers adjustment and even the osc trimmer, IF it seems to be required.
ZUJ'ing
73's de Edd
:
:
:
:
:
:
:
:
:
:With your forthcoming info, sounds like the BCB ant coil is wanting to be of less inductive in its value if #3 trimmer is wanting to be set to that low of a capacitive value to enhance low BCB reception. OR. . .the possibility of the I.F.'s not collectively being aligned closely enough to
:acquire the precise 470 kc tracking differential.
:
:
:Hows about trying a check on them, by evaluating with a minimum input condition, akin to such as you would be subjecting them to in the reception of a weak DX BCB station.
:
:
:
:This is considering the possibility that the initial alignment RF input level had swamped out the adjustments somewhat, making the I.F. peaking a bit broad in its adjustment, and wavering from tuned circuit to tuned circuit in the I.F. strip.
:
:
:
:What I do is confirm that my un modulated signal generator is right on by using a freq counter or use of its reception by a Digital receiver or the poor man's option of a simple tuning in of the sig gen to ~470 and use another receiver and tune in to a BCB station on 940 Kc and listen for the heterodyning of the 2nd harmonic of the 470 sig gen signal and trim in the sig gen freq to get a zero beat.
:
:
:
:My RG coax from the sig gen is terminated with an alligator clip so I just clip on to any cotton / plastic wiring on any portion of the common wiring connections between the ant coil, tuning condenser stator of the RF section or even the wiring running up to the mixer grid cap. That gets a weak "gimmick" coupled level of RF signal into the front end.
:
:
:
:The 400 Cycle mod is then turned on and the tuning condenser swung to the max open position and then the RF level of the sig generator is brought up until the signals tone can just be heard.
:Initially, the final IF winding at the detector stage is peaked and then the sequential IF tuned circuits working towards the plate of the mixer are peaked. That should be sufficient, unless the gain and sound level has come up enough such that you might want to do again using the minimum level of sig gen mod RF possible.
:
:
:
:My logic is to replicate the strips same weak levels as is experienced on trying to pull in weak DX BCB stations.
:
:
:
:Then, with your strip aligned in that manner, go back and do the RF alignment of that RF trimmers adjustment and even the osc trimmer, IF it seems to be required.
:
:
:
:Edd, I think you may be on to something, as I know that I do the alignment with way too much power/input. I guess I never thought that it made that much difference. I don't use an output meter,,just listen to the speaker. How about I give that a try tomorrow, and I'll let you know how it goes. Edd, thank you very much for the help
:73's de Edd
:
:
:
:
:
:
If I just bypass the antenna coil by connecting the antenna to the grid of #1 tube the radio would work ok. Now if the radio works better not using the antenna coil, why did Philco put it in?
Thanks for the help,
Tom
::
::
::
::
::
::
::
::
::
::
::With your forthcoming info, sounds like the BCB ant coil is wanting to be of less inductive in its value if #3 trimmer is wanting to be set to that low of a capacitive value to enhance low BCB reception. OR. . .the possibility of the I.F.'s not collectively being aligned closely enough to
::acquire the precise 470 kc tracking differential.
::
::
::Hows about trying a check on them, by evaluating with a minimum input condition, akin to such as you would be subjecting them to in the reception of a weak DX BCB station.
::
::
::
::This is considering the possibility that the initial alignment RF input level had swamped out the adjustments somewhat, making the I.F. peaking a bit broad in its adjustment, and wavering from tuned circuit to tuned circuit in the I.F. strip.
::
::
::
::What I do is confirm that my un modulated signal generator is right on by using a freq counter or use of its reception by a Digital receiver or the poor man's option of a simple tuning in of the sig gen to ~470 and use another receiver and tune in to a BCB station on 940 Kc and listen for the heterodyning of the 2nd harmonic of the 470 sig gen signal and trim in the sig gen freq to get a zero beat.
::
::
::
::My RG coax from the sig gen is terminated with an alligator clip so I just clip on to any cotton / plastic wiring on any portion of the common wiring connections between the ant coil, tuning condenser stator of the RF section or even the wiring running up to the mixer grid cap. That gets a weak "gimmick" coupled level of RF signal into the front end.
::
::
::
::The 400 Cycle mod is then turned on and the tuning condenser swung to the max open position and then the RF level of the sig generator is brought up until the signals tone can just be heard.
::Initially, the final IF winding at the detector stage is peaked and then the sequential IF tuned circuits working towards the plate of the mixer are peaked. That should be sufficient, unless the gain and sound level has come up enough such that you might want to do again using the minimum level of sig gen mod RF possible.
::
::
::
::My logic is to replicate the strips same weak levels as is experienced on trying to pull in weak DX BCB stations.
::
::
::
::Then, with your strip aligned in that manner, go back and do the RF alignment of that RF trimmers adjustment and even the osc trimmer, IF it seems to be required.
::
::
::
::Edd, I think you may be on to something, as I know that I do the alignment with way too much power/input. I guess I never thought that it made that much difference. I don't use an output meter,,just listen to the speaker. How about I give that a try tomorrow, and I'll let you know how it goes. Edd, thank you very much for the help
:
:
:
::73's de Edd
::
::
::
::
::
::
:
:If I just bypass the antenna coil by connecting the antenna to the grid of #1 tube the radio would work ok. Now if the radio works better not using the antenna coil, why did Philco put it in?
:
:Thanks for the help,
:Tom
:
:
:
:
:
:
:
:::
:::
:::
:::
:::
:::
:::
:::
:::
:::
:::With your forthcoming info, sounds like the BCB ant coil is wanting to be of less inductive in its value if #3 trimmer is wanting to be set to that low of a capacitive value to enhance low BCB reception. OR. . .the possibility of the I.F.'s not collectively being aligned closely enough to
:::acquire the precise 470 kc tracking differential.
:::
:::
:::Hows about trying a check on them, by evaluating with a minimum input condition, akin to such as you would be subjecting them to in the reception of a weak DX BCB station.
:::
:::
:::
:::This is considering the possibility that the initial alignment RF input level had swamped out the adjustments somewhat, making the I.F. peaking a bit broad in its adjustment, and wavering from tuned circuit to tuned circuit in the I.F. strip.
:::
:::
:::
:::What I do is confirm that my un modulated signal generator is right on by using a freq counter or use of its reception by a Digital receiver or the poor man's option of a simple tuning in of the sig gen to ~470 and use another receiver and tune in to a BCB station on 940 Kc and listen for the heterodyning of the 2nd harmonic of the 470 sig gen signal and trim in the sig gen freq to get a zero beat.
:::
:::
:::
:::My RG coax from the sig gen is terminated with an alligator clip so I just clip on to any cotton / plastic wiring on any portion of the common wiring connections between the ant coil, tuning condenser stator of the RF section or even the wiring running up to the mixer grid cap. That gets a weak "gimmick" coupled level of RF signal into the front end.
:::
:::
:::
:::The 400 Cycle mod is then turned on and the tuning condenser swung to the max open position and then the RF level of the sig generator is brought up until the signals tone can just be heard.
:::Initially, the final IF winding at the detector stage is peaked and then the sequential IF tuned circuits working towards the plate of the mixer are peaked. That should be sufficient, unless the gain and sound level has come up enough such that you might want to do again using the minimum level of sig gen mod RF possible.
:::
:::
:::
:::My logic is to replicate the strips same weak levels as is experienced on trying to pull in weak DX BCB stations.
:::
:::
:::
:::Then, with your strip aligned in that manner, go back and do the RF alignment of that RF trimmers adjustment and even the osc trimmer, IF it seems to be required.
:::
:::
:::
:::Edd, I think you may be on to something, as I know that I do the alignment with way too much power/input. I guess I never thought that it made that much difference. I don't use an output meter,,just listen to the speaker. How about I give that a try tomorrow, and I'll let you know how it goes. Edd, thank you very much for the help
::
::
::
:
:
:
:
:
:
:
:
:
:
:
:
:::73's de Edd
:::
:::
:::
:::
:::
:::
do you need a longer antenna?
::
::If I just bypass the antenna coil by connecting the antenna to the grid of #1 tube the radio would work ok. Now if the radio works better not using the antenna coil, why did Philco put it in?
::
::Thanks for the help,
::Tom
::
::
::
::
::
::
::
::::
::::
::::
::::
::::
::::
::::
::::
::::
::::
::::With your forthcoming info, sounds like the BCB ant coil is wanting to be of less inductive in its value if #3 trimmer is wanting to be set to that low of a capacitive value to enhance low BCB reception. OR. . .the possibility of the I.F.'s not collectively being aligned closely enough to
::::acquire the precise 470 kc tracking differential.
::::
::::
::::Hows about trying a check on them, by evaluating with a minimum input condition, akin to such as you would be subjecting them to in the reception of a weak DX BCB station.
::::
::::
::::
::::This is considering the possibility that the initial alignment RF input level had swamped out the adjustments somewhat, making the I.F. peaking a bit broad in its adjustment, and wavering from tuned circuit to tuned circuit in the I.F. strip.
::::
::::
::::
::::What I do is confirm that my un modulated signal generator is right on by using a freq counter or use of its reception by a Digital receiver or the poor man's option of a simple tuning in of the sig gen to ~470 and use another receiver and tune in to a BCB station on 940 Kc and listen for the heterodyning of the 2nd harmonic of the 470 sig gen signal and trim in the sig gen freq to get a zero beat.
::::
::::
::::
::::My RG coax from the sig gen is terminated with an alligator clip so I just clip on to any cotton / plastic wiring on any portion of the common wiring connections between the ant coil, tuning condenser stator of the RF section or even the wiring running up to the mixer grid cap. That gets a weak "gimmick" coupled level of RF signal into the front end.
::::
::::
::::
::::The 400 Cycle mod is then turned on and the tuning condenser swung to the max open position and then the RF level of the sig generator is brought up until the signals tone can just be heard.
::::Initially, the final IF winding at the detector stage is peaked and then the sequential IF tuned circuits working towards the plate of the mixer are peaked. That should be sufficient, unless the gain and sound level has come up enough such that you might want to do again using the minimum level of sig gen mod RF possible.
::::
::::
::::
::::My logic is to replicate the strips same weak levels as is experienced on trying to pull in weak DX BCB stations.
::::
::::
::::
::::Then, with your strip aligned in that manner, go back and do the RF alignment of that RF trimmers adjustment and even the osc trimmer, IF it seems to be required.
::::
::::
::::
::::Edd, I think you may be on to something, as I know that I do the alignment with way too much power/input. I guess I never thought that it made that much difference. I don't use an output meter,,just listen to the speaker. How about I give that a try tomorrow, and I'll let you know how it goes. Edd, thank you very much for the help
:::
:::
:::
::
::
::
::
::
::
::
::
::
::
::
::
::::73's de Edd
::::
::::
::::
::::
::::
::::
:
:do you need a longer antenna?
This could be, but I use this type of antenna on other 5 tube radios and they work fine. Must be something wrong, why does the radio work better when I bypass the antenna coil?
Thanks for any help,
Tom
BTW if using an aerial wire, did it route into terminal 1 and with you having terminals 2-3 shorted to each other with the swing away jumper clip ? So as you can see, your current affectation makes it seem like your tracking favoring the low end of the BCB band is in error. I can simplify the tracking alignment if you will locate a wide band noise source such that you might have around your home. ZUJ’ing for feedback.
O.K. with the IF strip now seeming to be of no further consequence in error upsetting any further analysis steps, isn’t that antenna coil having enough clearance around it such that you could reach in and thumb- index finger grip the main winding and see if the reception on those low band stations start to come up a bit?
Now you will have to confirm some data as I am blind-deaf-dumb to the mechanics atop and below the chassis.
I am tending to think between two situations, and we will take the easiest first. The first is that #8 oscillator coil for the BCB has two adjustments to it, there is the hex head screw adjustment to a trimmer capacitor as well as there being a second adjustment of a
concentric “screw” adjustment . . .refer to page 3 of the sets schematic on site here and you will see that there is the conventional trimmer that shunts the oscillator coil along with the Main tuning condensers variable oscillator section and the special portion that you may not be familiar with, that shunts a tap in the oscillator coil.
For a pictorial of that BCB oscillator coil and those trimmer caps, consult page 4 upper right corner.
The “screw” portion adjustment favors tracking at the 1600 Kc portion of the band and the “hex” adjustment aspect favors trimming optimal tracking at the 600 Kc portion of the BCB, and SMILE. . ..they mechanically inter react, unless you use the fiber tools or make your own. I used a 1/8 fiberglass sheet and fashioned an“open end wrench” using a Dremel tool and a cut off wheel then flat Swiss pattern files to fit in to precisely.
That was then letting me hold onto one adjustments setting while working with the other one, or conversely, PLUS they still tend to inter react capacitively a bit, so a few minor tweak adjustments are required.
My prime choice ones are an old style fluorescent table lamp with the old generation iron core ballast utilized in it.
The newer ones with the electronic ballasts, or a CFL lamp is less that desirable due to the high frequencies being clustered, and not giving a uniform broadband response.
I also have one soldering station that I built that uses a common solid state lamp dimmer in it that varies the AC voltage fed to a common soldering iron. Put it at about mid position and it is “Static City”
Hair driers using AC-DC motors (with brushes) used in the cool position, some electric razors, electric drill motors, Dremel tools, could all suffice. . . . one confirms by just turning them on and bringing up near a radios loop or its aerial wire and listening for the rich, whining static that will be emanating from the speaker on a desirable noise source.
73's de Edd
:
:
:
:
:
:
:
:
:
:
:O.K. with the IF strip now seeming to be of no further consequence in error upsetting any further analysis steps, isn’t that antenna coil having enough clearance around it such that you could reach in and thumb- index finger grip the main winding and see if the reception on those low band stations start to come up a bit?
:
:
:
:BTW if using an aerial wire, did it route into terminal 1 and with you having terminals 2-3 shorted to each other with the swing away jumper clip ?
:
:
:
:Now you will have to confirm some data as I am blind-deaf-dumb to the mechanics atop and below the chassis.
:I am tending to think between two situations, and we will take the easiest first. The first is that #8 oscillator coil for the BCB has two adjustments to it, there is the hex head screw adjustment to a trimmer capacitor as well as there being a second adjustment of a
:concentric “screw” adjustment . . .refer to page 3 of the sets schematic on site here and you will see that there is the conventional trimmer that shunts the oscillator coil along with the Main tuning condensers variable oscillator section and the special portion that you may not be familiar with, that shunts a tap in the oscillator coil.
:
:
:For a pictorial of that BCB oscillator coil and those trimmer caps, consult page 4 upper right corner.
:
:The “screw” portion adjustment favors tracking at the 1600 Kc portion of the band and the “hex” adjustment aspect favors trimming optimal tracking at the 600 Kc portion of the BCB, and SMILE. . ..they mechanically inter react, unless you use the fiber tools or make your own. I used a 1/8 fiberglass sheet and fashioned an“open end wrench” using a Dremel tool and a cut off wheel then flat Swiss pattern files to fit in to precisely.
:
:
:That was then letting me hold onto one adjustments setting while working with the other one, or conversely, PLUS they still tend to inter react capacitively a bit, so a few minor tweak adjustments are required.
:
:
:
:So as you can see, your current affectation makes it seem like your tracking favoring the low end of the BCB band is in error.
:
:
:
:I can simplify the tracking alignment if you will locate a wide band noise source such that you might have around your home.
:
:
:My prime choice ones are an old style fluorescent table lamp with the old generation iron core ballast utilized in it.
:
:
:The newer ones with the electronic ballasts, or a CFL lamp is less that desirable due to the high frequencies being clustered, and not giving a uniform broadband response.
:
:
:I also have one soldering station that I built that uses a common solid state lamp dimmer in it that varies the AC voltage fed to a common soldering iron. Put it at about mid position and it is “Static City”
:
:
:Hair driers using AC-DC motors (with brushes) used in the cool position, some electric razors, electric drill motors, Dremel tools, could all suffice. . . . one confirms by just turning them on and bringing up near a radios loop or its aerial wire and listening for the rich, whining static that will be emanating from the speaker on a desirable noise source.
:
:
:
:ZUJ’ing for feedback.
:
:
:
:
:
:
:73's de Edd
:
:
:
:
:
:
:
Edd thanks for getting back.
About getting my fingers around the antenna trans, I might be able to get my fingers around the outside of it but it is too small to get a finger inside.
next question, Yes you have pictured the setup correctly, and I follow you on the circuit with the osc. area. yes I do have the antenna/long wire connected the way that the info on this site directs me to.
I also understand what you say about holding one adjustment still while turning the other (osc. adjustment). I don't think that the screw was turning the outter nut but it may have-adjusting the low end of dial did not seem to mess up the upper end of the dial (other the amount one would expect).
I read about setting the signal gen to 800 and adjusting to second harmonic for the upper end of dial. Don't understand why they want me to do this but I tried it that way, and just setting the signal gen to 1600. no better.
I have fluorescent lights in the next room that allways drives the radios mad, guess that would work. So yes I would like to know of an easy way to align a radio.
Radio is back inside the cabnet now and I have to get up a 5:00am for work, after 9:00 now so I will be able to try what you say tomorrow, and get back to you.
Thanks again,
Tom
::
::
::
::
::
::
::
::
::
::
::O.K. with the IF strip now seeming to be of no further consequence in error upsetting any further analysis steps, isn’t that antenna coil having enough clearance around it such that you could reach in and thumb- index finger grip the main winding and see if the reception on those low band stations start to come up a bit?
::
::
::
::BTW if using an aerial wire, did it route into terminal 1 and with you having terminals 2-3 shorted to each other with the swing away jumper clip ?
::
::
::
::Now you will have to confirm some data as I am blind-deaf-dumb to the mechanics atop and below the chassis.
::I am tending to think between two situations, and we will take the easiest first. The first is that #8 oscillator coil for the BCB has two adjustments to it, there is the hex head screw adjustment to a trimmer capacitor as well as there being a second adjustment of a
::concentric “screw” adjustment . . .refer to page 3 of the sets schematic on site here and you will see that there is the conventional trimmer that shunts the oscillator coil along with the Main tuning condensers variable oscillator section and the special portion that you may not be familiar with, that shunts a tap in the oscillator coil.
::
::
::For a pictorial of that BCB oscillator coil and those trimmer caps, consult page 4 upper right corner.
::
::The “screw” portion adjustment favors tracking at the 1600 Kc portion of the band and the “hex” adjustment aspect favors trimming optimal tracking at the 600 Kc portion of the BCB, and SMILE. . ..they mechanically inter react, unless you use the fiber tools or make your own. I used a 1/8 fiberglass sheet and fashioned an“open end wrench” using a Dremel tool and a cut off wheel then flat Swiss pattern files to fit in to precisely.
::
::
::That was then letting me hold onto one adjustments setting while working with the other one, or conversely, PLUS they still tend to inter react capacitively a bit, so a few minor tweak adjustments are required.
::
::
::
::So as you can see, your current affectation makes it seem like your tracking favoring the low end of the BCB band is in error.
::
::
::
::I can simplify the tracking alignment if you will locate a wide band noise source such that you might have around your home.
::
::
::My prime choice ones are an old style fluorescent table lamp with the old generation iron core ballast utilized in it.
::
::
::The newer ones with the electronic ballasts, or a CFL lamp is less that desirable due to the high frequencies being clustered, and not giving a uniform broadband response.
::
::
::I also have one soldering station that I built that uses a common solid state lamp dimmer in it that varies the AC voltage fed to a common soldering iron. Put it at about mid position and it is “Static City”
::
::
::Hair driers using AC-DC motors (with brushes) used in the cool position, some electric razors, electric drill motors, Dremel tools, could all suffice. . . . one confirms by just turning them on and bringing up near a radios loop or its aerial wire and listening for the rich, whining static that will be emanating from the speaker on a desirable noise source.
::
::
::
::ZUJ’ing for feedback.
::
::
::
::
::
::
::73's de Edd
::
::
::
::
::
::
::
:
:
:Edd thanks for getting back.
:About getting my fingers around the antenna trans, I might be able to get my fingers around the outside of it but it is too small to get a finger inside.
:
:next question, Yes you have pictured the setup correctly, and I follow you on the circuit with the osc. area. yes I do have the antenna/long wire connected the way that the info on this site directs me to.
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:I also understand what you say about holding one adjustment still while turning the other (osc. adjustment). I don't think that the screw was turning the outter nut but it may have-adjusting the low end of dial did not seem to mess up the upper end of the dial (other the amount one would expect).
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:I read about setting the signal gen to 800 and adjusting to second harmonic for the upper end of dial. Don't understand why they want me to do this but I tried it that way, and just setting the signal gen to 1600. no better.
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:I have fluorescent lights in the next room that allways drives the radios mad, guess that would work. So yes I would like to know of an easy way to align a radio.
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:Radio is back inside the cabnet now and I have to get up a 5:00am for work, after 9:00 now so I will be able to try what you say tomorrow, and get back to you.
:
:Thanks again,
:Tom
:
Edd, This is an update on what I did tonight, First I tried to align the radio again. Tried many times very carefully, no better. After tring by the book and not getting anywhere, I tried some other things and I found that when I adjust the 600kc osc (nut) I can get it to bring in a staition that broadcasts on 680kc at about 750kc and it comes in very strong. Now I tried to bring this station down to where it should be, 680, by turning the osc nut alittle then retuning the dial again and again...but the closer I got to 680 on the dial the weaker the staition got.
And to answer one of your questions, when I touch the antenna transformer it does get louder, this was done with the radio aligned "correctly"
any ideas? thanks Tom
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:O.K. with the IF strip now seeming to be of no further consequence in error upsetting any further analysis steps, isn’t that antenna coil having enough clearance around it such that you could reach in and thumb- index finger grip the main winding and see if the reception on those low band stations start to come up a bit?
:
:
:
:BTW if using an aerial wire, did it route into terminal 1 and with you having terminals 2-3 shorted to each other with the swing away jumper clip ?
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:Now you will have to confirm some data as I am blind-deaf-dumb to the mechanics atop and below the chassis.
:I am tending to think between two situations, and we will take the easiest first. The first is that #8 oscillator coil for the BCB has two adjustments to it, there is the hex head screw adjustment to a trimmer capacitor as well as there being a second adjustment of a
:concentric “screw” adjustment . . .refer to page 3 of the sets schematic on site here and you will see that there is the conventional trimmer that shunts the oscillator coil along with the Main tuning condensers variable oscillator section and the special portion that you may not be familiar with, that shunts a tap in the oscillator coil.
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:For a pictorial of that BCB oscillator coil and those trimmer caps, consult page 4 upper right corner.
:
:The “screw” portion adjustment favors tracking at the 1600 Kc portion of the band and the “hex” adjustment aspect favors trimming optimal tracking at the 600 Kc portion of the BCB, and SMILE. . ..they mechanically inter react, unless you use the fiber tools or make your own. I used a 1/8 fiberglass sheet and fashioned an“open end wrench” using a Dremel tool and a cut off wheel then flat Swiss pattern files to fit in to precisely.
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:That was then letting me hold onto one adjustments setting while working with the other one, or conversely, PLUS they still tend to inter react capacitively a bit, so a few minor tweak adjustments are required.
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:So as you can see, your current affectation makes it seem like your tracking favoring the low end of the BCB band is in error.
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:I can simplify the tracking alignment if you will locate a wide band noise source such that you might have around your home.
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:My prime choice ones are an old style fluorescent table lamp with the old generation iron core ballast utilized in it.
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:The newer ones with the electronic ballasts, or a CFL lamp is less that desirable due to the high frequencies being clustered, and not giving a uniform broadband response.
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:I also have one soldering station that I built that uses a common solid state lamp dimmer in it that varies the AC voltage fed to a common soldering iron. Put it at about mid position and it is “Static City”
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:Hair driers using AC-DC motors (with brushes) used in the cool position, some electric razors, electric drill motors, Dremel tools, could all suffice. . . . one confirms by just turning them on and bringing up near a radios loop or its aerial wire and listening for the rich, whining static that will be emanating from the speaker on a desirable noise source.
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:ZUJ’ing for feedback.
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:73's de Edd
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Edd, I posted a question about this problem on another site, One idea that came up was is my signal generator any good? Well I tested it aganist a digital radio and it's output was very wide allmost all over the dial. So I tested another generator and it was much better only off by less then 10kc. I realigned the Philco with that one but it did not help much if any. got any ideas?
Tom
Sir Thomas:
Back with you after a wee hiatus in telecom-incommunicado land and now being fully recovered from a 3 day
turkey triptothane downer.
At the very onset of the month, there is some lag on accessing the last months data, during its spooling into
archiving, so I just had to sneak in the back door and retreive the initial thread.
With your now having done the alignment of the IF strip to a weak signal level, that specific aspect should now be in
order, and of minimal further concern.
Your description of the rise in low band sensitivity with the touching of the ant coil, further goes to confirm a non
uniformity of the sets tracking in the reception of the lower BCB frequencies, yet, with the mid to high band
aliognment being able to be set to spec and producing the required 470 Kc, differential on THOSE segments of the
BC band BUT, with there being error in the alignment in not being able to be produce that same 455 differential on the lower portion of the BC band.
Consult the markup supplied below on the dial scales that are depicting the possible lowband tracking errors that
could either stretch out or compress the tracking down in that lower BCB spectrum.
Looking at the referencing over to its right side we see that the top and very bottom scale logs are the same and
have a red referencing line dropped down between the tow and the two error possibilities showing up in the two center scales.
The 1600 and 1300 refs are right on spec, while at about the 1200 area, the differentials are starting to show.
USING A HORIZONTAL DIAL-SCALE REFERENCING:
Therefore, the heterodyning of the local osc frequency and the RF tuning down at that end of the band is currently
creating either a slightly less than / or more than the 470 Kc ideal I.F. value.
The net result of that error in frequency is that produced I.F. signal not receiving fully I.F. amplifier benefits, due to its
frequency being somewhat down on the response passband of the IF strip and that weaker level not getting the
benefit of full amplification capability of an I.F. freqency that is right on the prescribed 470 Kc, such as the tracking
on the mid band and hi band portion of the BCB currently are producing for you.
I.F. RESPONSE CURVE:
With your giving feed back of the fact that reception on a low band station (680) is enhanced by your shifting the
local oscillator frequency away from the previously aligned procedures result hints that there is fault with the
inductive value of the local oscillator.
Now there seems to be minimal fault with the oscillator trimming capacitor #8 (screw) adjusted capacitive value,
as that aligns in properly at 1600 . BUT if you refer to the schematic of the oscillator circuit, we see that there is
vaiance of the common oscillator circuit on other sets, versus your set, in the manner of there also being the
supplemental #8B (nut) adjustment for the dual capacitive compensator, which is so wired such that is resonating
in conjunction with a tap point on the oscillator coil.
WIth all of that preceding info at hand now, what I would ask you to try next is to make incremental adjustments of
the #8 NUT and SCREW adjustments such that as you initially observe that 680 stations position on the dial, you will
adjust #8 nut in the direction that is making your reception of the 680, (that is now coming in at ~750)
starting to move TOWARDS the 680 scale logging position. The two adjustments should inter-react such that
after a while that 1600 osc logging reference (of #8 nut adjustment) should start to be drifted off from,
unless you are simultaneously counter compensating with the adjustmnent of the #8 screw adjustment to
keep a 1600 signal tracking on the high end of the dial scale. E.G. more capacitance with one will be needing less capacitance with the other, or conversely. At intervals, check that the antenna trimmer capacitor
#3 is still optimizing reception of received signal at 1500.
Thassit for now. . . ..waiting for feed back. . . . .
Hmmmmmm. . . .now musing about The Great Litz Wire Scenario. . . . .BUT, assuredley not, since your inductance value is high and not low.
73's de Edd
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:Sir Thomas:
:
:
:Back with you after a wee hiatus in telecom-incommunicado land and now being fully recovered from a 3 day
:turkey triptothane downer.
:
:
:
:At the very onset of the month, there is some lag on accessing the last months data, during its spooling into
:
:archiving, so I just had to sneak in the back door and retreive the initial thread.
:
:
:
:With your now having done the alignment of the IF strip to a weak signal level, that specific aspect should now be in
:order, and of minimal further concern.
:
:
:
:Your description of the rise in low band sensitivity with the touching of the ant coil, further goes to confirm a non
:
:
:uniformity of the sets tracking in the reception of the lower BCB frequencies, yet, with the mid to high band
:
:
:aliognment being able to be set to spec and producing the required 470 Kc, differential on THOSE segments of the
:
:BC band BUT, with there being error in the alignment in not being able to be produce that same 455 differential on the lower portion of the BC band.
:
:Consult the markup supplied below on the dial scales that are depicting the possible lowband tracking errors that
:
:could either stretch out or compress the tracking down in that lower BCB spectrum.
:
:Looking at the referencing over to its right side we see that the top and very bottom scale logs are the same and
:
:
:have a red referencing line dropped down between the tow and the two error possibilities showing up in the two center scales.
:
:The 1600 and 1300 refs are right on spec, while at about the 1200 area, the differentials are starting to show.
:
:
:
:USING A HORIZONTAL DIAL-SCALE REFERENCING:
:
:
:
:
:
:
:
:Therefore, the heterodyning of the local osc frequency and the RF tuning down at that end of the band is currently
:
:
:creating either a slightly less than / or more than the 470 Kc ideal I.F. value.
:
:The net result of that error in frequency is that produced I.F. signal not receiving fully I.F. amplifier benefits, due to its
:
:
:frequency being somewhat down on the response passband of the IF strip and that weaker level not getting the
:
:
:benefit of full amplification capability of an I.F. freqency that is right on the prescribed 470 Kc, such as the tracking
:
:
:on the mid band and hi band portion of the BCB currently are producing for you.
:
:
:
: I.F. RESPONSE CURVE:
:
:
:
:
:
:With your giving feed back of the fact that reception on a low band station (680) is enhanced by your shifting the
:
:
:local oscillator frequency away from the previously aligned procedures result hints that there is fault with the
:inductive value of the local oscillator.
:
:Now there seems to be minimal fault with the oscillator trimming capacitor #8 (screw) adjusted capacitive value,
:
:as that aligns in properly at 1600 . BUT if you refer to the schematic of the oscillator circuit, we see that there is
:
:
:vaiance of the common oscillator circuit on other sets, versus your set, in the manner of there also being the
:
:
:supplemental #8B (nut) adjustment for the dual capacitive compensator, which is so wired such that is resonating
:
:
:in conjunction with a tap point on the oscillator coil.
:
:
:
:
:
:
:
:WIth all of that preceding info at hand now, what I would ask you to try next is to make incremental adjustments of
:
:the #8 NUT and SCREW adjustments such that as you initially observe that 680 stations position on the dial, you will
:adjust #8 nut in the direction that is making your reception of the 680, (that is now coming in at ~750)
:starting to move TOWARDS the 680 scale logging position. The two adjustments should inter-react such that
:after a while that 1600 osc logging reference (of #8 nut adjustment) should start to be drifted off from,
:unless you are simultaneously counter compensating with the adjustmnent of the #8 screw adjustment to
:keep a 1600 signal tracking on the high end of the dial scale. E.G. more capacitance with one will be needing less capacitance with the other, or conversely. At intervals, check that the antenna trimmer capacitor
: #3 is still optimizing reception of received signal at 1500.
:
:
:
:Thassit for now. . . ..waiting for feed back. . . . .
:
:Hmmmmmm. . . .now musing about The Great Litz Wire Scenario. . . . .BUT, assuredley not, since your inductance value is high and not low.
:
:
:
:
:
:73's de Edd
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:Edd, That is what I did many times, I would adjust the osc. to bring the 680 station at around 750 and it would come in strong. than I would "chase" it down the dial. Turning the osc. adjustment a little than tune the station back in down the dial a little untill the 680 station comes in at around 680 on the dial. Now I did this many times last week also adjusting the other osc. adjustment to keep the upper staitions in line, and not making adjustments to the other adjustment. no matter what I did by the time I got it down to the correct place on the dial the station was very weak.
If you can see the schematic shows the resistance of the two halves of the osc. coil, I checked them and they were both very close to the spec.
Tom