Don't have a Variac, but do have an European/USA 220 to 110 VAC transformer (100W). I'm thinking plug the 220 side into the 110 line socket and the radio into the 110 on the transformer to bring it up first time.
Forum opinion is desired!!!

marv

Hi Marv

That will work. These transformers may not be exactly 1:2, to make up for loses but close enough.

Norm

:Don't have a Variac, but do have an European/USA 220 to 110 VAC transformer (100W). I'm thinking plug the 220 side into the 110 line socket and the radio into the 110 on the transformer to bring it up first time.
:Forum opinion is desired!!!
:
:marv

Norm,
The transformer worked great. Built a spread sheet and got lots of data at 1/2 and full line voltage with/without tubes. Doesn't work (yet) though. Think the oscillator has gone south. Although it was a total rebuild, caps, resistors and wiring that crumbled. Don't think I have any errors there, because each component/wire was disconnected at one end only, new stuff added at that junction, then second end connected. This was an idea I came up with to avoid using my headlamp/magnifier constantly to read the schematic. I'll scope it tomorrow.

marv

:Hi Marv
:
: That will work. These transformers may not be exactly 1:2, to make up for loses but close enough.
:
:Norm
:
::Don't have a Variac, but do have an European/USA 220 to 110 VAC transformer (100W). I'm thinking plug the 220 side into the 110 line socket and the radio into the 110 on the transformer to bring it up first time.
::Forum opinion is desired!!!
::
::marv

Norm,
Well, didn't follow my own rule. Added the ground I left ground off cathode of 2nd detector, still didn't work. Took the tube out and put it in the tester. All 3 sections bad, but it wasn't warm. Wiggled it in the socket, then it started to warm up and test marginally good. Back into the set, and all is well. Think its something more serious than just pin/socket problem. The tube may have a broken lead inside its base, and I just got lucky. Still got to polish up the align and dial pointer position before it goes back in the case. For those asking about the speaker performance after salvaging the cone with rubber like craft glue a couple weeks ago. SOUNDS FINE TO MY TIN EAR, but only found 1 station on SW with music, and it faded out too soon.

marv

:Norm,
:The transformer worked great. Built a spread sheet and got lots of data at 1/2 and full line voltage with/without tubes. Doesn't work (yet) though. Think the oscillator has gone south. Although it was a total rebuild, caps, resistors and wiring that crumbled. Don't think I have any errors there, because each component/wire was disconnected at one end only, new stuff added at that junction, then second end connected. This was an idea I came up with to avoid using my headlamp/magnifier constantly to read the schematic. I'll scope it tomorrow.
:
:marv
:
::Hi Marv
::
:: That will work. These transformers may not be exactly 1:2, to make up for loses but close enough.
::
::Norm
::
:::Don't have a Variac, but do have an European/USA 220 to 110 VAC transformer (100W). I'm thinking plug the 220 side into the 110 line socket and the radio into the 110 on the transformer to bring it up first time.
:::Forum opinion is desired!!!
:::
:::marv

Marv

I've found some tubes with bad solder connections at the pins. Usually on older types but could happen on octals. Try resoldering pin #7 and #8 on your 12SQ7. That must have been the one which didn't heat at first?

Norm

:Norm,
:Well, didn't follow my own rule. Added the ground I left ground off cathode of 2nd detector, still didn't work. Took the tube out and put it in the tester. All 3 sections bad, but it wasn't warm. Wiggled it in the socket, then it started to warm up and test marginally good. Back into the set, and all is well. Think its something more serious than just pin/socket problem. The tube may have a broken lead inside its base, and I just got lucky. Still got to polish up the align and dial pointer position before it goes back in the case. For those asking about the speaker performance after salvaging the cone with rubber like craft glue a couple weeks ago. SOUNDS FINE TO MY TIN EAR, but only found 1 station on SW with music, and it faded out too soon.
:
:marv
:
::Norm,
::The transformer worked great. Built a spread sheet and got lots of data at 1/2 and full line voltage with/without tubes. Doesn't work (yet) though. Think the oscillator has gone south. Although it was a total rebuild, caps, resistors and wiring that crumbled. Don't think I have any errors there, because each component/wire was disconnected at one end only, new stuff added at that junction, then second end connected. This was an idea I came up with to avoid using my headlamp/magnifier constantly to read the schematic. I'll scope it tomorrow.
::
::marv
::
:::Hi Marv
:::
::: That will work. These transformers may not be exactly 1:2, to make up for loses but close enough.
:::
:::Norm
:::
::::Don't have a Variac, but do have an European/USA 220 to 110 VAC transformer (100W). I'm thinking plug the 220 side into the 110 line socket and the radio into the 110 on the transformer to bring it up first time.
::::Forum opinion is desired!!!
::::
::::marv

:Norm,
Looked at the pins, and they looked clean (6SQ7), but maybe re-heating them and adding a little clean solder will help. Turned it off and walked away for a hour or so, went back and same symptom. Wiggled the tube (no help) did the power switch a few times and it came up. Baffled!!!

marv
:
: I've found some tubes with bad solder connections at the pins. Usually on older types but could happen on octals. Try resoldering pin #7 and #8 on your 12SQ7. That must have been the one which didn't heat at first?
:
:Norm
:
::Norm,
::Well, didn't follow my own rule. Added the ground I left ground off cathode of 2nd detector, still didn't work. Took the tube out and put it in the tester. All 3 sections bad, but it wasn't warm. Wiggled it in the socket, then it started to warm up and test marginally good. Back into the set, and all is well. Think its something more serious than just pin/socket problem. The tube may have a broken lead inside its base, and I just got lucky. Still got to polish up the align and dial pointer position before it goes back in the case. For those asking about the speaker performance after salvaging the cone with rubber like craft glue a couple weeks ago. SOUNDS FINE TO MY TIN EAR, but only found 1 station on SW with music, and it faded out too soon.
::
::marv
::
:::Norm,
:::The transformer worked great. Built a spread sheet and got lots of data at 1/2 and full line voltage with/without tubes. Doesn't work (yet) though. Think the oscillator has gone south. Although it was a total rebuild, caps, resistors and wiring that crumbled. Don't think I have any errors there, because each component/wire was disconnected at one end only, new stuff added at that junction, then second end connected. This was an idea I came up with to avoid using my headlamp/magnifier constantly to read the schematic. I'll scope it tomorrow.
:::
:::marv
:::
::::Hi Marv
::::
:::: That will work. These transformers may not be exactly 1:2, to make up for loses but close enough.
::::
::::Norm
::::
:::::Don't have a Variac, but do have an European/USA 220 to 110 VAC transformer (100W). I'm thinking plug the 220 side into the 110 line socket and the radio into the 110 on the transformer to bring it up first time.
:::::Forum opinion is desired!!!
:::::
:::::marv

I have found that the 1st triode amplifier in most radios will perform quite well even if it tests in the replace region. Keep this in mind whenever you find one that is a dud tester-wise. It could, of course, be gassy. Otherwise, though, the currents involved in the detector and in the amplifier are so low that it doesn't take much to pass them. Remember that the plate load resistor on the triode is often from several hundred thousand ohms to a million ohms.

Thomas

Marv

Maybe just intermittent filament? Testing won't catch this.

Norm

::Norm,
:Looked at the pins, and they looked clean (6SQ7), but maybe re-heating them and adding a little clean solder will help. Turned it off and walked away for a hour or so, went back and same symptom. Wiggled the tube (no help) did the power switch a few times and it came up. Baffled!!!
:
:marv
::
:: I've found some tubes with bad solder connections at the pins. Usually on older types but could happen on octals. Try resoldering pin #7 and #8 on your 12SQ7. That must have been the one which didn't heat at first?
::
::Norm
::
:::Norm,
:::Well, didn't follow my own rule. Added the ground I left ground off cathode of 2nd detector, still didn't work. Took the tube out and put it in the tester. All 3 sections bad, but it wasn't warm. Wiggled it in the socket, then it started to warm up and test marginally good. Back into the set, and all is well. Think its something more serious than just pin/socket problem. The tube may have a broken lead inside its base, and I just got lucky. Still got to polish up the align and dial pointer position before it goes back in the case. For those asking about the speaker performance after salvaging the cone with rubber like craft glue a couple weeks ago. SOUNDS FINE TO MY TIN EAR, but only found 1 station on SW with music, and it faded out too soon.
:::
:::marv
:::
::::Norm,
::::The transformer worked great. Built a spread sheet and got lots of data at 1/2 and full line voltage with/without tubes. Doesn't work (yet) though. Think the oscillator has gone south. Although it was a total rebuild, caps, resistors and wiring that crumbled. Don't think I have any errors there, because each component/wire was disconnected at one end only, new stuff added at that junction, then second end connected. This was an idea I came up with to avoid using my headlamp/magnifier constantly to read the schematic. I'll scope it tomorrow.
::::
::::marv
::::
:::::Hi Marv
:::::
::::: That will work. These transformers may not be exactly 1:2, to make up for loses but close enough.
:::::
:::::Norm
:::::
::::::Don't have a Variac, but do have an European/USA 220 to 110 VAC transformer (100W). I'm thinking plug the 220 side into the 110 line socket and the radio into the 110 on the transformer to bring it up first time.
::::::Forum opinion is desired!!!
::::::
::::::marv

Norm,
Re-soldered the tube pins and cleaned the socket again, and the symptom disappeared. Used the AVC line to peak the IF's. Tried to use the RCA info (osc. slug for 600kHz and C29 for 1500kHz) to set the dial pointer, but didn't help. Kept getting farther off. Reversed the process, and got almost exactly on. Don't have a sig. gen, so had to use broadcast stations near those freqs. Is this a common problem with these old documents/radios?

marv

:Marv
:
: Maybe just intermittent filament? Testing won't catch this.
:
:Norm
:
:::Norm,
::Looked at the pins, and they looked clean (6SQ7), but maybe re-heating them and adding a little clean solder will help. Turned it off and walked away for a hour or so, went back and same symptom. Wiggled the tube (no help) did the power switch a few times and it came up. Baffled!!!
::
::marv
:::
::: I've found some tubes with bad solder connections at the pins. Usually on older types but could happen on octals. Try resoldering pin #7 and #8 on your 12SQ7. That must have been the one which didn't heat at first?
:::
:::Norm
:::
::::Norm,
::::Well, didn't follow my own rule. Added the ground I left ground off cathode of 2nd detector, still didn't work. Took the tube out and put it in the tester. All 3 sections bad, but it wasn't warm. Wiggled it in the socket, then it started to warm up and test marginally good. Back into the set, and all is well. Think its something more serious than just pin/socket problem. The tube may have a broken lead inside its base, and I just got lucky. Still got to polish up the align and dial pointer position before it goes back in the case. For those asking about the speaker performance after salvaging the cone with rubber like craft glue a couple weeks ago. SOUNDS FINE TO MY TIN EAR, but only found 1 station on SW with music, and it faded out too soon.
::::
::::marv
::::
:::::Norm,
:::::The transformer worked great. Built a spread sheet and got lots of data at 1/2 and full line voltage with/without tubes. Doesn't work (yet) though. Think the oscillator has gone south. Although it was a total rebuild, caps, resistors and wiring that crumbled. Don't think I have any errors there, because each component/wire was disconnected at one end only, new stuff added at that junction, then second end connected. This was an idea I came up with to avoid using my headlamp/magnifier constantly to read the schematic. I'll scope it tomorrow.
:::::
:::::marv
:::::
::::::Hi Marv
::::::
:::::: That will work. These transformers may not be exactly 1:2, to make up for loses but close enough.
::::::
::::::Norm
::::::
:::::::Don't have a Variac, but do have an European/USA 220 to 110 VAC transformer (100W). I'm thinking plug the 220 side into the 110 line socket and the radio into the 110 on the transformer to bring it up first time.
:::::::Forum opinion is desired!!!
:::::::
:::::::marv

You must be right on with the IF transformers. A signal generator is a must. I usually tune mine using a long wave radio. This assures me that I have the exact frequency tuned in. After this, perfect station tracking is possible.

Thomas

This a new obscure, but somewhat noticable problem, and only occurs in the SW mode, when tuning. If I use a slow deliberate rotation of the knob (typical), all is well, but if I do fast somewhat jerking rotation, I get static like the condenser plates are dragging. Thinking the condenser shaft was loose, moving off center and making the plates drag, I checked it, but is not the problem. This is a new experience for me, and appears to be purely electrical. Am I missing something?

marv

:You must be right on with the IF transformers. A signal generator is a must. I usually tune mine using a long wave radio. This assures me that I have the exact frequency tuned in. After this, perfect station tracking is possible.
:
:Thomas

Yep. You're missing the tuning shaft and/or the condenser shaft. Lubricate them with di-electric grease. If you cannot get the static to go away, perhaps a pressure spring against the inside end of the tuning shaft will help. A strap of spring metal soldered to the chassis that rests against the inner end of the shaft will keep pressure on it, and force it in an outward direction. This will keep the connection more solid between the shaft and the chassis. You shouldn't be getting too much static from the shaft unless you're touching it directly, though. The knobs often provide enough insulation to minimize the connection between your body and the shaft. Otherwise, when you touch the shaft directly, it's just like holding a screw driver and dragging it across the chassis. ....You may still have trouble with the shaft in some sensitive radios, even when turning it with a knob.

Thomas

Thomas,
But wouldn't the same shaft cause the same noise on the AM band as well? The condenser frame is rubber isolated mechanically from the chassis, but is still soldered to it with copper strips.

marv

:Yep. You're missing the tuning shaft and/or the condenser shaft. Lubricate them with di-electric grease. If you cannot get the static to go away, perhaps a pressure spring against the inside end of the tuning shaft will help. A strap of spring metal soldered to the chassis that rests against the inner end of the shaft will keep pressure on it, and force it in an outward direction. This will keep the connection more solid between the shaft and the chassis. You shouldn't be getting too much static from the shaft unless you're touching it directly, though. The knobs often provide enough insulation to minimize the connection between your body and the shaft. Otherwise, when you touch the shaft directly, it's just like holding a screw driver and dragging it across the chassis. ....You may still have trouble with the shaft in some sensitive radios, even when turning it with a knob.
:
:Thomas

Where is that post about old phono cartridge output levels vs the newer crystal parts? Getting bad distortion trying to play old LPs on a newer player thru the phono jack on the 16T2. The turntable is '01-'02 model.

marv

:Yep. You're missing the tuning shaft and/or the condenser shaft. Lubricate them with di-electric grease. If you cannot get the static to go away, perhaps a pressure spring against the inside end of the tuning shaft will help. A strap of spring metal soldered to the chassis that rests against the inner end of the shaft will keep pressure on it, and force it in an outward direction. This will keep the connection more solid between the shaft and the chassis. You shouldn't be getting too much static from the shaft unless you're touching it directly, though. The knobs often provide enough insulation to minimize the connection between your body and the shaft. Otherwise, when you touch the shaft directly, it's just like holding a screw driver and dragging it across the chassis. ....You may still have trouble with the shaft in some sensitive radios, even when turning it with a knob.
:
:Thomas

Well, that is strange that it's only on short wave. Can't think of much, really. I'd say that there's a loose coil connection. The oscillator coil is all one, though, and isn't anywhere near the tuning condenser. You say that the static only happens when you tune. Could be the selector switch being vibrated, but it isn't anywhere near the tuning...it is, but not enough to be mechanically linked. ...Though it could be vibrated with the radio in its cabinet with the knobs on. Turning one knob could vibrate the cabinet, and in turn vibrate the other knob, which would vibrate the selector switch.

Could also be the antenna coil....but I doubt it.

Regarding the phonograph, that is strange. I assume that you replaced all condensers. If not, make sure you replace the ones at the input. Does the audio distort at all levels, or just quiet, or just loud (within reason)? Usually the audio is fed into the ends of the volume control, with the grid being fed from the center terminal, so I can't see loading of the cartridge as a normal option for a problem.

Be sure that you are connecting both channels properly (if the phonograph is stereo). Try hooking up only one channel. If it sounds good, you may have them out of phase with eachother when wiring up both.

Thomas

Thomas,
Something unique about the SW band, but took the tuning condenser out, cleaned it with degreaser first, then a mild acid to brighten the brass ground contacts to the stator and seems to have cleared up the static when tuning on SW. No tensioning adjustments were made. Took Peter Balazsy's advice and added a couple cotton balls between the cone and frame, which improved the audio markedly, especially when using the phono input. O'scoped the audio level at the phono input, and found an average of 0.7 volts PP, so excess level is not a concern. Don't know how good this set was in it's hey-day, but sounds pretty decent now at medium volume levels. The mild audio artifacts I'm hearing now are only at lower volume and close-up listening. Without an audio gen, its difficult to pinpoint these subtle artifacts at the output.

marv

:Well, that is strange that it's only on short wave. Can't think of much, really. I'd say that there's a loose coil connection. The oscillator coil is all one, though, and isn't anywhere near the tuning condenser. You say that the static only happens when you tune. Could be the selector switch being vibrated, but it isn't anywhere near the tuning...it is, but not enough to be mechanically linked. ...Though it could be vibrated with the radio in its cabinet with the knobs on. Turning one knob could vibrate the cabinet, and in turn vibrate the other knob, which would vibrate the selector switch.
:
:Could also be the antenna coil....but I doubt it.
:
:Regarding the phonograph, that is strange. I assume that you replaced all condensers. If not, make sure you replace the ones at the input. Does the audio distort at all levels, or just quiet, or just loud (within reason)? Usually the audio is fed into the ends of the volume control, with the grid being fed from the center terminal, so I can't see loading of the cartridge as a normal option for a problem.
:
:Be sure that you are connecting both channels properly (if the phonograph is stereo). Try hooking up only one channel. If it sounds good, you may have them out of phase with eachother when wiring up both.
:
:Thomas

I agree that a Sig Gen is best... but Sometimes I just use my frequency counter.

I tune to a known station like 770khz.

Then put my freq counter probe near the local oscillator and read it. ( not directly connected to avoid loading down the oscillator)

I slowly re-tune or trim the radio dial till I read 1225khz on the freq counter.
( 455khz above 770khz = 1225khz)

When I see exactly 1225khz I know that the mixer must now be producing exactly 455khz.
.. then I can just peak the IFs knowing that my IF signal is a perfect 455khz.