Hey folks,
This is on the Philco 41-285.
Thought I'd regroup here. Found numerous mistakes in the radio. Now I have all good voltages. I set the radio at 800khz and the good radio at 1255khz and I hear the oscillator working through the good radio. I still have no reception at all. Hum from the speaker is less. I'm told that this radio was taken to a shop to be repaired and the shop could not fix it. I'm wondering how many trimmers and padders were played with. Would anyone recommend a full alignment at this point?
Thanks, Johnny

Whenever this kind of thing occurs, it is always best to start at the output of the radio and move back through the radio. This would include a tune-up. First check the audio stages to make sure that you can send a signal (hum from finger) through all the way from the volume control. Then check the IF stages with your signal generator. Then check all of the front end circuits for proper alignment and for oscillator operation (which you say is working). This procedure will reveal just about everything you need to know.

There isn't much to a radio except capacitors, resistors, and coils (and tubes). If you get to a dead point, check coils for continuity, capacitors for shorts (and opens), and resistors for opens (and drifting). If all checks out well, check to see that you can tune coils to frequency. If you can't, there may be a partial short within the coil. If this is the case, it would help to have a chart of DC resistances for the coils.

...And finally check ALL wiring, and check individual tube element continuity (can be done with most tube testers).

T.

:Whenever this kind of thing occurs, it is always best to start at the output of the radio and move back through the radio. This would include a tune-up. First check the audio stages to make sure that you can send a signal (hum from finger) through all the way from the volume control. Then check the IF stages with your signal generator. Then check all of the front end circuits for proper alignment and for oscillator operation (which you say is working). This procedure will reveal just about everything you need to know.
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:There isn't much to a radio except capacitors, resistors, and coils (and tubes). If you get to a dead point, check coils for continuity, capacitors for shorts (and opens), and resistors for opens (and drifting). If all checks out well, check to see that you can tune coils to frequency. If you can't, there may be a partial short within the coil. If this is the case, it would help to have a chart of DC resistances for the coils.
:
:...And finally check ALL wiring, and check individual tube element continuity (can be done with most tube testers).
:
:T.

Good advice. When the oscillator is working, and the set has audio output and gain, and someone tells about the radio being taken to a shop and found to be non-repairable, the most common problem I have found is one of the IF transformers. Either an open winding (wire was stripped with acid before soldering, and not cleaned well - over time the remaining acid eats the wire in two), or leaching of silver in one of the internal capacitors. Other folks may have had other experience.

:Whenever this kind of thing occurs, it is always best to start at the output of the radio and move back through the radio. This would include a tune-up. First check the audio stages to make sure that you can send a signal (hum from finger) through all the way from the volume control. Then check the IF stages with your signal generator. Then check all of the front end circuits for proper alignment and for oscillator operation (which you say is working). This procedure will reveal just about everything you need to know.
::
::There isn't much to a radio except capacitors, resistors, and coils (and tubes). If you get to a dead point, check coils for continuity, capacitors for shorts (and opens), and resistors for opens (and drifting). If all checks out well, check to see that you can tune coils to frequency. If you can't, there may be a partial short within the coil. If this is the case, it would help to have a chart of DC resistances for the coils.
::
::...And finally check ALL wiring, and check individual tube element continuity (can be done with most tube testers).
::
::T.
:
:Good advice. When the oscillator is working, and the set has audio output and gain, and someone tells about the radio being taken to a shop and found to be non-repairable, the most common problem I have found is one of the IF transformers. Either an open winding (wire was stripped with acid before soldering, and not cleaned well - over time the remaining acid eats the wire in two), or leaching of silver in one of the internal capacitors. Other folks may have had other experience.
:
:Hi Ed M! Talk to me some more. I've been all through these IF cans, resistance checks etc. and I am finding no anomalies. Right now the radio is taken apart again. I could find nothing anywhere in the radio that was bad so I decided to pull the band switch out again and go through it. I'm seeing no anomalies, just dirty. All Loctals and their sockets have been thoroughly cleaned also.

Let me ask. I know this radio has been messed with. Is there any basic setting for all trimmers and padders to be set? In other words... screw it all the way down and then back out 1/4, 1/2 turn and so on?

With capacitor trimmers, 1 turn is a good place to start. However, messing around with the trimmers to get reception is pretty much shooting in the dark. Follow the advice I gave you and let us know how far you get. Start at the speaker and work your way back until you can't get a signal to go through (from your signal generator or finger). That is a logical straight-forward way of going about it. Once you can't get a signal, the trouble most likely lies within that stage. You CAN find the trouble. Aside from measuring capacitors and resistors, IF transformers should usually have from about 10 to 80 ohms resistance. FM IF transformers will generally be less than this, but you're not dealing with FM in this radio.

This procedure will usually solve just about every "doesn't work" problem that arises on this forum.

T.

:With capacitor trimmers, 1 turn is a good place to start. However, messing around with the trimmers to get reception is pretty much shooting in the dark. Follow the advice I gave you and let us know how far you get. Start at the speaker and work your way back until you can't get a signal to go through (from your signal generator or finger). That is a logical straight-forward way of going about it. Once you can't get a signal, the trouble most likely lies within that stage. You CAN find the trouble. Aside from measuring capacitors and resistors, IF transformers should usually have from about 10 to 80 ohms resistance. FM IF transformers will generally be less than this, but you're not dealing with FM in this radio.
:
:This procedure will usually solve just about every "doesn't work" problem that arises on this forum.
:
:
:T.

I always start at the power supply wwith a Voltmeter and check Voltages. Then I check the audio amplifiers with an audio generator or a transistor (battery operated) with a minature phone jack plugged into the output, and connected across the volume control. These are the simpler circuits to troubleshoot. Once you have those working to your satisfaction, you are ready to tackle the RF, Osc-mixer, and the IF, 455 kHz or whatever, and backward to the oscillator-mixer, which you say you can find on a good radio. Great, that is about the hardest part of the radio to understand and repair. But first, check the audio. A finger to the center tap of the vollume control will give us all a wealth of information.
Lewis

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: : : : : : : : : : : : : : :Thought that you had that dude in a quasi- operational state ? : : : :With initial consideration to be given to the probably ok. . . power supply levels. . . . and then in considering the audio portions of the receiver, would you evaluate that portion in the following manner for me. : : : : Almost ZERO requirements, in equipment, although I think ? that I remember you gradually adding onto your test equipment cache. Should the following modulated 455 R.F. signal be needed on the follow up. : : :What you need is a . . .on the safe side. . . .600VDC rated . .. coupling capacitor of a .001 ufd value and two test leads with clip ends. : : :Consult your schematic and note the coupling of the sets low level audio from the detector stage via the item #38 which is an .01 ufd cap. : : :Then have power down and lift one end of that cap. . .the easiest one to do. Then connect a clip lead to one of the plates of one of the #41 AF output tubes (50/50 chance of being right here. . ..phasing considerations) and then the other end of that clip lead gets connected to one lead of that aforementioned .001 cap, with its other lead receiving another test leads clip and then the free test lead clip goes to the high side of the volume control where the other cap . . . .just lifted. . .. .was cutting off the incoming radio audio. : : :NOW if you power up and warm up the set with the volume at its minimum, you should then be able to slowly advance the volume control and find yourself with an audio sweep :oscillator. : : :That being, from the initial acoustical antics of a cricket ( on steroids) on upwards thru the resonant frequency of the speaker cone and then the cabinet resonance ( if so contained within) up to the point where some of the higher frequencies should drive Aunt Murgatriod out of the guest bedroom. . . in a frenzied state of panic shock. : : :Should the oscillation effect not have occurred, then you need to move that plate lead connection clip over to the OTHER 41’s plate connection. : : :Somewhere within that sweep the audio level should approach the most volume that the set will ever produce. . . .thus confirming adequate current and voltage supply being present for your audio circuitry as well as the audio portion being up to par. : : : : Some evaluation of the tone control circuitry can even be made at the higher frequencies by the “colorization” of the tone control, upon the produced signal. : : : :Next question. . ..after the mod RF sig generator availability will be if you have . . . ..preferably, one of the OLD generation fluorescent desk lamps with 1-2 small tubes and the “all important” OLD generation common metal ballast transformer. : : : :(Also, some aquariums top illumination lamps, are of that category as well as “gro lux” plant lamps, kids older style black light lamps, etc.) : : : :The new generation CFL lamps with their “electronic ballasts” are LESS than desirable with their sharp banding of switch mode activity within 60-75-120 khz clusters. : : : : : :Standing by. . . .. : : : : : : : : : :73's de Edd ::> : : : :

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:Thanks for getting back Edd. And everyone else too. I will perform these tasks as soon as the radio is back together again. Knocked off at 10 last night and here it is 3:45 am and I'm back at it. Should be done soon. Couldn't sleep anyway.
This is my nephews first resto job. A few mistakes were made and I believe I have identified all of them and made the necessary corrections. I did however decide to pull the band switch assembly because it is the only thing I haven't thoroughly checked. Found mostly dirt in this area. I am having some trouble making sense of the pinouts on the "OSC. TRANS." as pictured on the schematic. Bottom center of page. It looks as if pin 1 is at the right then pin 4 is the next pin at the top of the coil with the black dot next to it. Then pin 7 (also black dot) and 5 on left side. Pin 3 and 2 appear to be at the bottom of the coil. It also appears that pin 6 is at the top of the back of the coil. Is this view looking down with the chassis upside down or looking down with the chassis right side up? With the chassis upside down and looking down at the osc. trans my pin 6 is at the bottom. Not as pictured at the top. Once again, what's the view? I can't trust the nephews connections so I really need to determine this. Lots of connections between band switch and these coils. "ANT. TRANS." is much easier to read but once again... What is the view on this? Looking up, down etc.?
I really do appreciate the help with this and I know we'll get it figured out. Now! Any advice on how to teach a young man patience? I'm telling him that you just can't rush through one of these things.
Thanks folks,
Johnny

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: : : : : : : : : : : : : : :Thought that you had that dude in a quasi- operational state ? : : : :With initial consideration to be given to the probably ok. . . power supply levels. . . . and then in considering the audio portions of the receiver, would you evaluate that portion in the following manner for me. : : : : Almost ZERO requirements, in equipment, although I think ? that I remember you gradually adding onto your test equipment cache. Should the following modulated 455 R.F. signal be needed on the follow up. : : :What you need is a . . .on the safe side. . . .600VDC rated . .. coupling capacitor of a .001 ufd value and two test leads with clip ends. : : :Consult your schematic and note the coupling of the sets low level audio from the detector stage via the item #38 which is an .01 ufd cap. : : :Then have power down and lift one end of that cap. . .the easiest one to do. Then connect a clip lead to one of the plates of one of the #41 AF output tubes (50/50 chance of being right here. . ..phasing considerations) and then the other end of that clip lead gets connected to one lead of that aforementioned .001 cap, with its other lead receiving another test leads clip and then the free test lead clip goes to the high side of the volume control where the other cap . . . .just lifted. . .. .was cutting off the incoming radio audio. : : :NOW if you power up and warm up the set with the volume at its minimum, you should then be able to slowly advance the volume control and find yourself with an audio sweep :oscillator. : : :That being, from the initial acoustical antics of a cricket ( on steroids) on upwards thru the resonant frequency of the speaker cone and then the cabinet resonance ( if so contained within) up to the point where some of the higher frequencies should drive Aunt Murgatriod out of the guest bedroom. . . in a frenzied state of panic shock. : : :Should the oscillation effect not have occurred, then you need to move that plate lead connection clip over to the OTHER 41’s plate connection. : : :Somewhere within that sweep the audio level should approach the most volume that the set will ever produce. . . .thus confirming adequate current and voltage supply being present for your audio circuitry as well as the audio portion being up to par. : : : : Some evaluation of the tone control circuitry can even be made at the higher frequencies by the “colorization” of the tone control, upon the produced signal. : : : :Next question. . ..after the mod RF sig generator availability will be if you have . . . ..preferably, one of the OLD generation fluorescent desk lamps with 1-2 small tubes and the “all important” OLD generation common metal ballast transformer. : : : :(Also, some aquariums top illumination lamps, are of that category as well as “gro lux” plant lamps, kids older style black light lamps, etc.) : : : :The new generation CFL lamps with their “electronic ballasts” are LESS than desirable with their sharp banding of switch mode activity within 60-75-120 khz clusters. : : : : : :Standing by. . . .. : : : : : : : : : :73's de Edd ::> : : : :

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:Thanks for getting back Edd. And everyone else too. I will perform these tasks as soon as the radio is back together again. Knocked off at 10 last night and here it is 3:45 am and I'm back at it. Should be done soon. Couldn't sleep anyway.
This is my nephews first resto job. A few mistakes were made and I believe I have identified all of them and made the necessary corrections. I did however decide to pull the band switch assembly because it is the only thing I haven't thoroughly checked. Found mostly dirt in this area. I am having some trouble making sense of the pinouts on the "OSC. TRANS." as pictured on the schematic. Bottom center of page. It looks as if pin 1 is at the right then pin 4 is the next pin at the top of the coil with the black dot next to it. Then pin 7 (also black dot) and 5 on left side. Pin 3 and 2 appear to be at the bottom of the coil. It also appears that pin 6 is at the top of the back of the coil. Is this view looking down with the chassis upside down or looking down with the chassis right side up? With the chassis upside down and looking down at the osc. trans my pin 6 is at the bottom. Not as pictured at the top. Once again, what's the view? I can't trust the nephews connections so I really need to determine this. Lots of connections between band switch and these coils. "ANT. TRANS." is much easier to read but once again... What is the view on this? Looking up, down etc.?
I really do appreciate the help with this and I know we'll get it figured out. Now! Any advice on how to teach a young man patience? I'm telling him that you just can't rush through one of these things.
Thanks folks,
Johnny

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4/15/2009 11:38:29 AMDoug H(73107:73073)

::Thanks for getting back Edd. And everyone else too. I will perform these tasks as soon as the radio is back together again. Knocked off at 10 last night and here it is 3:45 am and I'm back at it. Should be done soon. Couldn't sleep anyway.
:This is my nephews first resto job. A few mistakes were made and I believe I have identified all of them and made the necessary corrections. I did however decide to pull the band switch assembly because it is the only thing I haven't thoroughly checked. Found mostly dirt in this area. I am having some trouble making sense of the pinouts on the "OSC. TRANS." as pictured on the schematic. Bottom center of page. It looks as if pin 1 is at the right then pin 4 is the next pin at the top of the coil with the black dot next to it. Then pin 7 (also black dot) and 5 on left side. Pin 3 and 2 appear to be at the bottom of the coil. It also appears that pin 6 is at the top of the back of the coil. Is this view looking down with the chassis upside down or looking down with the chassis right side up? With the chassis upside down and looking down at the osc. trans my pin 6 is at the bottom. Not as pictured at the top. Once again, what's the view? I can't trust the nephews connections so I really need to determine this. Lots of connections between band switch and these coils. "ANT. TRANS." is much easier to read but once again... What is the view on this? Looking up, down etc.?
:I really do appreciate the help with this and I know we'll get it figured out. Now! Any advice on how to teach a young man patience? I'm telling him that you just can't rush through one of these things.
:Thanks folks,
:Johnny
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:

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: The way that I am seeing that osc coil terminals, is per the enhancement. Now, as far as the locational dimensional view, rely upon the sole one sided terminal reference of # 6 at the very bottom. Additionally , use for referencing, the physical presence of the 22k resistor that is shunting terminals #5 and #6. 73's de Edd :

: : :: : Hi Johnny, I have a Philco 41-290 that I just picked up and havn't started on yet. After reading your post and EDD's comments and pictures, I decided to pull the chassis and have a look. The schematic is the same as yours except for the #37 phase inverter tube. The underside of the chassis are identical as far as part layout. I can take a picture of the underside of the chassis for you to view, and can email it to you. I believe I still have your email address when we mailed back and forth on the Grunow 589 a couple of months back. Do you want the pictures sent so you can see how everything is wired? My unit looks like it has never been touched, even has the original e-Caps. Let me know, Doug H 4/15/2009 12:01:14 PMJohnny(73109:73107) : :::Thanks for getting back Edd. And everyone else too. I will perform these tasks as soon as the radio is back together again. Knocked off at 10 last night and here it is 3:45 am and I'm back at it. Should be done soon. Couldn't sleep anyway. ::This is my nephews first resto job. A few mistakes were made and I believe I have identified all of them and made the necessary corrections. I did however decide to pull the band switch assembly because it is the only thing I haven't thoroughly checked. Found mostly dirt in this area. I am having some trouble making sense of the pinouts on the "OSC. TRANS." as pictured on the schematic. Bottom center of page. It looks as if pin 1 is at the right then pin 4 is the next pin at the top of the coil with the black dot next to it. Then pin 7 (also black dot) and 5 on left side. Pin 3 and 2 appear to be at the bottom of the coil. It also appears that pin 6 is at the top of the back of the coil. Is this view looking down with the chassis upside down or looking down with the chassis right side up? With the chassis upside down and looking down at the osc. trans my pin 6 is at the bottom. Not as pictured at the top. Once again, what's the view? I can't trust the nephews connections so I really need to determine this. Lots of connections between band switch and these coils. "ANT. TRANS." is much easier to read but once again... What is the view on this? Looking up, down etc.? ::I really do appreciate the help with this and I know we'll get it figured out. Now! Any advice on how to teach a young man patience? I'm telling him that you just can't rush through one of these things. ::Thanks folks, ::Johnny :: :: :: :: :: : : : : : : : : : : : : :: : :The way that I am seeing that osc coil terminals, is per the enhancement. :Now, as far as the locational dimensional view, rely upon the sole one sided terminal reference of # 6 at the very bottom. Additionally , use for referencing, the physical presence of the 22k resistor that is shunting terminals #5 and #6. : : : : : : : : :73's de Edd : : : : :: : :: :: ::: :: : : :Hi Johnny, : : I have a Philco 41-290 that I just picked up and havn't started on yet. After reading your post and EDD's comments and pictures, I decided to pull the chassis and have a look. The schematic is the same as yours except for the #37 phase inverter tube. The underside of the chassis are identical as far as part layout. I can take a picture of the underside of the chassis for you to view, and can email it to you. I believe I still have your email address when we mailed back and forth on the Grunow 589 a couple of months back. : :Do you want the pictures sent so you can see how everything is wired? My unit looks like it has never been touched, even has the original e-Caps. : :Let me know, Doug H : :That would be a great help Doug just in case I am still counting these pins backwards or upside down, inside out etc. Clicking on my name should get you my email again. Thanks!!! Just for additional backup a pic of the Ant. Trans. #3 on the schematic would help too. I could double check myself on that one too. Thanks again! Johnny 4/15/2009 12:40:43 PMDoug H(73110:73109) :: ::::Thanks for getting back Edd. And everyone else too. I will perform these tasks as soon as the radio is back together again. Knocked off at 10 last night and here it is 3:45 am and I'm back at it. Should be done soon. Couldn't sleep anyway. :::This is my nephews first resto job. A few mistakes were made and I believe I have identified all of them and made the necessary corrections. I did however decide to pull the band switch assembly because it is the only thing I haven't thoroughly checked. Found mostly dirt in this area. I am having some trouble making sense of the pinouts on the "OSC. TRANS." as pictured on the schematic. Bottom center of page. It looks as if pin 1 is at the right then pin 4 is the next pin at the top of the coil with the black dot next to it. Then pin 7 (also black dot) and 5 on left side. Pin 3 and 2 appear to be at the bottom of the coil. It also appears that pin 6 is at the top of the back of the coil. Is this view looking down with the chassis upside down or looking down with the chassis right side up? With the chassis upside down and looking down at the osc. trans my pin 6 is at the bottom. Not as pictured at the top. Once again, what's the view? I can't trust the nephews connections so I really need to determine this. Lots of connections between band switch and these coils. "ANT. TRANS." is much easier to read but once again... What is the view on this? Looking up, down etc.? :::I really do appreciate the help with this and I know we'll get it figured out. Now! Any advice on how to teach a young man patience? I'm telling him that you just can't rush through one of these things. :::Thanks folks, :::Johnny ::: ::: ::: ::: ::: :: :: :: :: :: :: :: :: :: :: :: :: ::: :: ::The way that I am seeing that osc coil terminals, is per the enhancement. ::Now, as far as the locational dimensional view, rely upon the sole one sided terminal reference of # 6 at the very bottom. Additionally , use for referencing, the physical presence of the 22k resistor that is shunting terminals #5 and #6. :: :: :: :: :: :: :: :: ::73's de Edd :: :: :: :: ::: :: ::: ::: :::: ::: :: :: ::Hi Johnny, :: :: I have a Philco 41-290 that I just picked up and havn't started on yet. After reading your post and EDD's comments and pictures, I decided to pull the chassis and have a look. The schematic is the same as yours except for the #37 phase inverter tube. The underside of the chassis are identical as far as part layout. I can take a picture of the underside of the chassis for you to view, and can email it to you. I believe I still have your email address when we mailed back and forth on the Grunow 589 a couple of months back. :: ::Do you want the pictures sent so you can see how everything is wired? My unit looks like it has never been touched, even has the original e-Caps. :: ::Let me know, Doug H :: ::That would be a great help Doug just in case I am still counting these pins backwards or upside down, inside out etc. Clicking on my name should get you my email again. Thanks!!! Just for additional backup a pic of the Ant. Trans. #3 on the schematic would help too. I could double check myself on that one too. Thanks again! Johnny Johnny, Pictures have been sent, Doug H 4/15/2009 5:51:49 PMJohnny(73124:73110) ::: :::::Thanks for getting back Edd. And everyone else too. I will perform these tasks as soon as the radio is back together again. Knocked off at 10 last night and here it is 3:45 am and I'm back at it. Should be done soon. Couldn't sleep anyway. ::::This is my nephews first resto job. A few mistakes were made and I believe I have identified all of them and made the necessary corrections. I did however decide to pull the band switch assembly because it is the only thing I haven't thoroughly checked. Found mostly dirt in this area. I am having some trouble making sense of the pinouts on the "OSC. TRANS." as pictured on the schematic. Bottom center of page. It looks as if pin 1 is at the right then pin 4 is the next pin at the top of the coil with the black dot next to it. Then pin 7 (also black dot) and 5 on left side. Pin 3 and 2 appear to be at the bottom of the coil. It also appears that pin 6 is at the top of the back of the coil. Is this view looking down with the chassis upside down or looking down with the chassis right side up? With the chassis upside down and looking down at the osc. trans my pin 6 is at the bottom. Not as pictured at the top. Once again, what's the view? I can't trust the nephews connections so I really need to determine this. Lots of connections between band switch and these coils. "ANT. TRANS." is much easier to read but once again... What is the view on this? Looking up, down etc.? ::::I really do appreciate the help with this and I know we'll get it figured out. Now! Any advice on how to teach a young man patience? I'm telling him that you just can't rush through one of these things. ::::Thanks folks, ::::Johnny :::: :::: :::: :::: :::: ::: ::: ::: ::: ::: ::: ::: ::: ::: ::: ::: ::: :::: ::: :::The way that I am seeing that osc coil terminals, is per the enhancement. :::Now, as far as the locational dimensional view, rely upon the sole one sided terminal reference of # 6 at the very bottom. Additionally , use for referencing, the physical presence of the 22k resistor that is shunting terminals #5 and #6. ::: ::: ::: ::: ::: ::: ::: ::: :::73's de Edd ::: ::: ::: ::: :::: ::: :::: :::: ::::: :::: ::: ::: :::Hi Johnny, ::: ::: I have a Philco 41-290 that I just picked up and havn't started on yet. After reading your post and EDD's comments and pictures, I decided to pull the chassis and have a look. The schematic is the same as yours except for the #37 phase inverter tube. The underside of the chassis are identical as far as part layout. I can take a picture of the underside of the chassis for you to view, and can email it to you. I believe I still have your email address when we mailed back and forth on the Grunow 589 a couple of months back. ::: :::Do you want the pictures sent so you can see how everything is wired? My unit looks like it has never been touched, even has the original e-Caps. ::: :::Let me know, Doug H ::: :::That would be a great help Doug just in case I am still counting these pins backwards or upside down, inside out etc. Clicking on my name should get you my email again. Thanks!!! Just for additional backup a pic of the Ant. Trans. #3 on the schematic would help too. I could double check myself on that one too. Thanks again! Johnny : : :Johnny, Pictures have been sent, : :Doug H : :Got 'em Doug. That helped alot to verify that these things are wired correctly.Thanks! Johnny 4/15/2009 11:54:15 AMJohnny(73108:73073) :Hello Edd. Your enhanced drawing of the coil really helped. Believe I have the pinouts correct now. I'm still putting the chassis back together. Should have it done today and then I'll see if it still has problems. I'll be back later today. Thanks much, Johnny : : : : : : : : :::: :::: :::: :::: :::: :::: :::: :::: :::: :::: :::: :::: ::::: :::: ::::The way that I am seeing that osc coil terminals, is per the enhancement. ::::Now, as far as the locational dimensional view, rely upon the sole one sided terminal reference of # 6 at the very bottom. Additionally , use for referencing, the physical presence of the 22k resistor that is shunting terminals #5 and #6. :::: :::: :::: :::: :::: :::: :::: :::: ::::73's de Edd :::: :::: :::: :::: ::::: :::: : :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: ::Thought that you had that dude in a quasi- operational state ? :: :: :: ::With initial consideration to be given to the probably ok. . . power supply levels. . . . and then in considering the audio portions of the receiver, would you evaluate that portion in the following manner for me. :: :: :: :: Almost ZERO requirements, in equipment, although I think ? that I remember you gradually adding onto your test equipment cache. Should the following modulated 455 R.F. signal be needed on the follow up. :: :: ::What you need is a . . .on the safe side. . . .600VDC rated . .. coupling capacitor of a .001 ufd value and two test leads with clip ends. :: :: ::Consult your schematic and note the coupling of the sets low level audio from the detector stage via the item #38 which is an .01 ufd cap. :: :: ::Then have power down and lift one end of that cap. . .the easiest one to do. Then connect a clip lead to one of the plates of one of the #41 AF output tubes (50/50 chance of being right here. . ..phasing considerations) and then the other end of that clip lead gets connected to one lead of that aforementioned .001 cap, with its other lead receiving another test leads clip and then the free test lead clip goes to the high side of the volume control where the other cap . . . .just lifted. . .. .was cutting off the incoming radio audio. :: :: ::NOW if you power up and warm up the set with the volume at its minimum, you should then be able to slowly advance the volume control and find yourself with an audio sweep ::oscillator. :: :: ::That being, from the initial acoustical antics of a cricket ( on steroids) on upwards thru the resonant frequency of the speaker cone and then the cabinet resonance ( if so contained within) up to the point where some of the higher frequencies should drive Aunt Murgatriod out of the guest bedroom. . . in a frenzied state of panic shock. :: :: ::Should the oscillation effect not have occurred, then you need to move that plate lead connection clip over to the OTHER 41’s plate connection. :: :: ::Somewhere within that sweep the audio level should approach the most volume that the set will ever produce. . . .thus confirming adequate current and voltage supply being present for your audio circuitry as well as the audio portion being up to par. :: :: :: :: Some evaluation of the tone control circuitry can even be made at the higher frequencies by the “colorization” of the tone control, upon the produced signal. :: :: :: ::Next question. . ..after the mod RF sig generator availability will be if you have . . . ..preferably, one of the OLD generation fluorescent desk lamps with 1-2 small tubes and the “all important” OLD generation common metal ballast transformer. :: :: :: ::(Also, some aquariums top illumination lamps, are of that category as well as “gro lux” plant lamps, kids older style black light lamps, etc.) :: :: :: ::The new generation CFL lamps with their “electronic ballasts” are LESS than desirable with their sharp banding of switch mode activity within 60-75-120 khz clusters. :: :: :: :: :: ::Standing by. . . .. :: :: :: :: :: :: :: :: :: ::73's de Edd ::::> :: :: :: :: :: :: :: ::Thanks for getting back Edd. And everyone else too. I will perform these tasks as soon as the radio is back together again. Knocked off at 10 last night and here it is 3:45 am and I'm back at it. Should be done soon. Couldn't sleep anyway. :This is my nephews first resto job. A few mistakes were made and I believe I have identified all of them and made the necessary corrections. I did however decide to pull the band switch assembly because it is the only thing I haven't thoroughly checked. Found mostly dirt in this area. I am having some trouble making sense of the pinouts on the "OSC. TRANS." as pictured on the schematic. Bottom center of page. It looks as if pin 1 is at the right then pin 4 is the next pin at the top of the coil with the black dot next to it. Then pin 7 (also black dot) and 5 on left side. Pin 3 and 2 appear to be at the bottom of the coil. It also appears that pin 6 is at the top of the back of the coil. Is this view looking down with the chassis upside down or looking down with the chassis right side up? With the chassis upside down and looking down at the osc. trans my pin 6 is at the bottom. Not as pictured at the top. Once again, what's the view? I can't trust the nephews connections so I really need to determine this. Lots of connections between band switch and these coils. "ANT. TRANS." is much easier to read but once again... What is the view on this? Looking up, down etc.? :I really do appreciate the help with this and I know we'll get it figured out. Now! Any advice on how to teach a young man patience? I'm telling him that you just can't rush through one of these things. :Thanks folks, :Johnny : : :: : 4/15/2009 7:58:16 PMJohnny(73126:73073) :Hello Edd and everyone kind enough to be a part of my latest dilemna. The radio is back together and I have performed some tests. The results are as follows. 1. I now have 116VDC at the plate of the 1st detecetor XXL. 2. Retested oscillator with known good AM radio and it's working fine. 3. Rechecked all voltages. 1st Det. XXL plate=116vdc. Oscillator XXL plate=45vdc. 1st IF 7B7 plate=202vdc. 2nd IF 7B7 plate=202vdc. 2nd Det. AVC 7A6 pin 3= -2.6vdc, pin 6= -.6vdc. 1st audio 7C6 plate=134vdc. Plates of 41's=198vdc. Grids of 41's are 195vdc and 205vdc. 4. Performed the audio test that Edd suggested and it does turn the radio into an audio sweep oscillator. So I guess audio circuit is working well. 5. This is where it gets funny. While performing the voltage checks I noticed that when I touch the positive lead of my DVM (neg. lead to chassis ground) to the plates of the 7B7 tubes the incoming signal (about 870 on the dial) increases and the volume also increases. This also happens when I touch my DVM lead to the plates of the 7A6 tube. So this is what I have so far. I'm currently limited on test equipment. I have a Heath frequency generator that works well at the lower freq's 455Khz included. I also have a freq. counter. So where do I go from here? Thanks everyone!!! Johnny : : : : : : : : : : : : : : : : : : : : :: : :The way that I am seeing that osc coil terminals, is per the enhancement. :Now, as far as the locational dimensional view, rely upon the sole one sided terminal reference of # 6 at the very bottom. Additionally , use for referencing, the physical presence of the 22k resistor that is shunting terminals #5 and #6. : : : : : : : : :73's de Edd : : : : :: : : :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: ::Thought that you had that dude in a quasi- operational state ? :: :: :: ::With initial consideration to be given to the probably ok. . . power supply levels. . . . and then in considering the audio portions of the receiver, would you evaluate that portion in the following manner for me. :: :: :: :: Almost ZERO requirements, in equipment, although I think ? that I remember you gradually adding onto your test equipment cache. Should the following modulated 455 R.F. signal be needed on the follow up. :: :: ::What you need is a . . .on the safe side. . . .600VDC rated . .. coupling capacitor of a .001 ufd value and two test leads with clip ends. :: :: ::Consult your schematic and note the coupling of the sets low level audio from the detector stage via the item #38 which is an .01 ufd cap. :: :: ::Then have power down and lift one end of that cap. . .the easiest one to do. Then connect a clip lead to one of the plates of one of the #41 AF output tubes (50/50 chance of being right here. . ..phasing considerations) and then the other end of that clip lead gets connected to one lead of that aforementioned .001 cap, with its other lead receiving another test leads clip and then the free test lead clip goes to the high side of the volume control where the other cap . . . .just lifted. . .. .was cutting off the incoming radio audio. :: :: ::NOW if you power up and warm up the set with the volume at its minimum, you should then be able to slowly advance the volume control and find yourself with an audio sweep ::oscillator. :: :: ::That being, from the initial acoustical antics of a cricket ( on steroids) on upwards thru the resonant frequency of the speaker cone and then the cabinet resonance ( if so contained within) up to the point where some of the higher frequencies should drive Aunt Murgatriod out of the guest bedroom. . . in a frenzied state of panic shock. :: :: ::Should the oscillation effect not have occurred, then you need to move that plate lead connection clip over to the OTHER 41’s plate connection. :: :: ::Somewhere within that sweep the audio level should approach the most volume that the set will ever produce. . . .thus confirming adequate current and voltage supply being present for your audio circuitry as well as the audio portion being up to par. :: :: :: :: Some evaluation of the tone control circuitry can even be made at the higher frequencies by the “colorization” of the tone control, upon the produced signal. :: :: :: ::Next question. . ..after the mod RF sig generator availability will be if you have . . . ..preferably, one of the OLD generation fluorescent desk lamps with 1-2 small tubes and the “all important” OLD generation common metal ballast transformer. :: :: :: ::(Also, some aquariums top illumination lamps, are of that category as well as “gro lux” plant lamps, kids older style black light lamps, etc.) :: :: :: ::The new generation CFL lamps with their “electronic ballasts” are LESS than desirable with their sharp banding of switch mode activity within 60-75-120 khz clusters. :: :: :: :: :: ::Standing by. . . .. :: :: :: :: :: :: :: :: :: ::73's de Edd ::::> :: :: :: :: :: :: :: ::Thanks for getting back Edd. And everyone else too. I will perform these tasks as soon as the radio is back together again. Knocked off at 10 last night and here it is 3:45 am and I'm back at it. Should be done soon. Couldn't sleep anyway. :This is my nephews first resto job. A few mistakes were made and I believe I have identified all of them and made the necessary corrections. I did however decide to pull the band switch assembly because it is the only thing I haven't thoroughly checked. Found mostly dirt in this area. I am having some trouble making sense of the pinouts on the "OSC. TRANS." as pictured on the schematic. Bottom center of page. It looks as if pin 1 is at the right then pin 4 is the next pin at the top of the coil with the black dot next to it. Then pin 7 (also black dot) and 5 on left side. Pin 3 and 2 appear to be at the bottom of the coil. It also appears that pin 6 is at the top of the back of the coil. Is this view looking down with the chassis upside down or looking down with the chassis right side up? With the chassis upside down and looking down at the osc. trans my pin 6 is at the bottom. Not as pictured at the top. Once again, what's the view? I can't trust the nephews connections so I really need to determine this. Lots of connections between band switch and these coils. "ANT. TRANS." is much easier to read but once again... What is the view on this? Looking up, down etc.? :I really do appreciate the help with this and I know we'll get it figured out. Now! Any advice on how to teach a young man patience? I'm telling him that you just can't rush through one of these things. :Thanks folks, :Johnny : : :: : 4/16/2009 2:15:42 AMJohnny(73137:73058) :With capacitor trimmers, 1 turn is a good place to start. However, messing around with the trimmers to get reception is pretty much shooting in the dark. Follow the advice I gave you and let us know how far you get. Start at the speaker and work your way back until you can't get a signal to go through (from your signal generator or finger). That is a logical straight-forward way of going about it. Once you can't get a signal, the trouble most likely lies within that stage. You CAN find the trouble. Aside from measuring capacitors and resistors, IF transformers should usually have from about 10 to 80 ohms resistance. FM IF transformers will generally be less than this, but you're not dealing with FM in this radio. : :This procedure will usually solve just about every "doesn't work" problem that arises on this forum. : : :T. : :Thanks Thomas! I have the radio put back together again and have verified the audio circuit is good and oscillator is good. I've never performed checks by hooking up my freq. gen.. How do you do this? Check the various stages? Where do I induce the signal at and what should the signal be? 455Khz? Further down in my posts I explain further what has been done. What voltages are etc. Thanks, Johnny 4/15/2009 11:21:15 PMThe Rework Is Done(73135:72976) :Hey folks, :This is on the Philco 41-285. :Thought I'd regroup here. Found numerous mistakes in the radio. Now I have all good voltages. I set the radio at 800khz and the good radio at 1255khz and I hear the oscillator working through the good radio. I still have no reception at all. Hum from the speaker is less. I'm told that this radio was taken to a shop to be repaired and the shop could not fix it. I'm wondering how many trimmers and padders were played with. Would anyone recommend a full alignment at this point? :Thanks, Johnny © 1989-2025, Nostalgia Air : : : : : : : : : : : : :: : :The way that I am seeing that osc coil terminals, is per the enhancement. :Now, as far as the locational dimensional view, rely upon the sole one sided terminal reference of # 6 at the very bottom. Additionally , use for referencing, the physical presence of the 22k resistor that is shunting terminals #5 and #6. : : : : : : : : :73's de Edd : : : : :: :