Philco 41-231 tuning

5/7/2003 12:35:36 AMtundrahawk

This one has really got me! The 41-231 is the pushbutton version of the old 41-221 with the handle and the plastic grill that sags form heat and age. After I cranked up the radio and put in good tubes it would receive 650 and 700 MC simultaneously in 2 areas of the variable tuner. I replaced all the caps and filters, even the speaker and got clear sound but still the same simultaneous reception in two places. I had an old 221 for parts so I replaced the first IF transformer. No change. Then the 2nd IF, no change, then the 3rd IF transformer. Still exactly the same. Then the oscillator transformer. Then finally the antenna transformer plus I realigned everything. I get a nice clear sound exactly the same with the 650 and 700 mixed (only stations received) on 2 places mid dial. I've eliminated about everything, what else could it be?? Im about to sell the whole project!

5/7/2003 11:43:19 AMNorm Leal

Probably your oscillator isn't operating? Check voltages around your XXD tube. See if you hear the oscillator in a second radio tuned 455KC above your Philco.

Norm

:This one has really got me! The 41-231 is the pushbutton version of the old 41-221 with the handle and the plastic grill that sags form heat and age. After I cranked up the radio and put in good tubes it would receive 650 and 700 MC simultaneously in 2 areas of the variable tuner. I replaced all the caps and filters, even the speaker and got clear sound but still the same simultaneous reception in two places. I had an old 221 for parts so I replaced the first IF transformer. No change. Then the 2nd IF, no change, then the 3rd IF transformer. Still exactly the same. Then the oscillator transformer. Then finally the antenna transformer plus I realigned everything. I get a nice clear sound exactly the same with the 650 and 700 mixed (only stations received) on 2 places mid dial. I've eliminated about everything, what else could it be?? Im about to sell the whole project!

5/7/2003 9:23:45 PMexray

I agree with Norm's reply. I just conquered a 42-327 with a weak oscillator. When it wasn't osc'ing the one local station would bleed thru slightly all across the dial with certain definite peaks.
My problem was the result of a bad mica cap in the XXD osc circuit that I had skipped over umpteen times.
-Bill

:Hi
:
: Probably your oscillator isn't operating? Check voltages around your XXD tube. See if you hear the oscillator in a second radio tuned 455KC above your Philco.
:
:Norm
:
::This one has really got me! The 41-231 is the pushbutton version of the old 41-221 with the handle and the plastic grill that sags form heat and age. After I cranked up the radio and put in good tubes it would receive 650 and 700 MC simultaneously in 2 areas of the variable tuner. I replaced all the caps and filters, even the speaker and got clear sound but still the same simultaneous reception in two places. I had an old 221 for parts so I replaced the first IF transformer. No change. Then the 2nd IF, no change, then the 3rd IF transformer. Still exactly the same. Then the oscillator transformer. Then finally the antenna transformer plus I realigned everything. I get a nice clear sound exactly the same with the 650 and 700 mixed (only stations received) on 2 places mid dial. I've eliminated about everything, what else could it be?? Im about to sell the whole project!

5/8/2003 3:37:09 PMtundrahawk

Hi again, I get no sound from the 2nd radio at 455KC so maybe that's it. Ck'd all the resistors except the mica's. Will do that. Need a primer on cking voltages. Do that on AC? and use the neg. input as ground, not the chassis? Tks, T.

:I agree with Norm's reply. I just conquered a 42-327 with a weak oscillator. When it wasn't osc'ing the one local station would bleed thru slightly all across the dial with certain definite peaks.
:My problem was the result of a bad mica cap in the XXD osc circuit that I had skipped over umpteen times.
:-Bill
:
:
::Hi
::
:: Probably your oscillator isn't operating? Check voltages around your XXD tube. See if you hear the oscillator in a second radio tuned 455KC above your Philco.
::
::Norm
::
:::This one has really got me! The 41-231 is the pushbutton version of the old 41-221 with the handle and the plastic grill that sags form heat and age. After I cranked up the radio and put in good tubes it would receive 650 and 700 MC simultaneously in 2 areas of the variable tuner. I replaced all the caps and filters, even the speaker and got clear sound but still the same simultaneous reception in two places. I had an old 221 for parts so I replaced the first IF transformer. No change. Then the 2nd IF, no change, then the 3rd IF transformer. Still exactly the same. Then the oscillator transformer. Then finally the antenna transformer plus I realigned everything. I get a nice clear sound exactly the same with the 650 and 700 mixed (only stations received) on 2 places mid dial. I've eliminated about everything, what else could it be?? Im about to sell the whole project!

5/8/2003 4:32:53 PMNorm Leal

Use the DC setting on your meter. Negative to B-, usually negative side of filter caps. Tube plates should be positive.

Norm

:Hi again, I get no sound from the 2nd radio at 455KC so maybe that's it. Ck'd all the resistors except the mica's. Will do that. Need a primer on cking voltages. Do that on AC? and use the neg. input as ground, not the chassis? Tks, T.
:
::I agree with Norm's reply. I just conquered a 42-327 with a weak oscillator. When it wasn't osc'ing the one local station would bleed thru slightly all across the dial with certain definite peaks.
::My problem was the result of a bad mica cap in the XXD osc circuit that I had skipped over umpteen times.
::-Bill
::
::
:::Hi
:::
::: Probably your oscillator isn't operating? Check voltages around your XXD tube. See if you hear the oscillator in a second radio tuned 455KC above your Philco.
:::
:::Norm
:::
::::This one has really got me! The 41-231 is the pushbutton version of the old 41-221 with the handle and the plastic grill that sags form heat and age. After I cranked up the radio and put in good tubes it would receive 650 and 700 MC simultaneously in 2 areas of the variable tuner. I replaced all the caps and filters, even the speaker and got clear sound but still the same simultaneous reception in two places. I had an old 221 for parts so I replaced the first IF transformer. No change. Then the 2nd IF, no change, then the 3rd IF transformer. Still exactly the same. Then the oscillator transformer. Then finally the antenna transformer plus I realigned everything. I get a nice clear sound exactly the same with the 650 and 700 mixed (only stations received) on 2 places mid dial. I've eliminated about everything, what else could it be?? Im about to sell the whole project!

5/10/2003 12:33:18 AMtundrahawk

Hi again, I'm testing the mica caps around the XXD. l These are brown, that means something? Arn't they in pico farads? My Fluke only tests to nano farads. The mica's I'm testing don't even come up on my nano scale. Do I just replace them and test the set? T.

:Hi
:
: Use the DC setting on your meter. Negative to B-, usually negative side of filter caps. Tube plates should be positive.
:
:Norm
:
::Hi again, I get no sound from the 2nd radio at 455KC so maybe that's it. Ck'd all the resistors except the mica's. Will do that. Need a primer on cking voltages. Do that on AC? and use the neg. input as ground, not the chassis? Tks, T.
::
:::I agree with Norm's reply. I just conquered a 42-327 with a weak oscillator. When it wasn't osc'ing the one local station would bleed thru slightly all across the dial with certain definite peaks.
:::My problem was the result of a bad mica cap in the XXD osc circuit that I had skipped over umpteen times.
:::-Bill
:::
:::
::::Hi
::::
:::: Probably your oscillator isn't operating? Check voltages around your XXD tube. See if you hear the oscillator in a second radio tuned 455KC above your Philco.
::::
::::Norm
::::
:::::This one has really got me! The 41-231 is the pushbutton version of the old 41-221 with the handle and the plastic grill that sags form heat and age. After I cranked up the radio and put in good tubes it would receive 650 and 700 MC simultaneously in 2 areas of the variable tuner. I replaced all the caps and filters, even the speaker and got clear sound but still the same simultaneous reception in two places. I had an old 221 for parts so I replaced the first IF transformer. No change. Then the 2nd IF, no change, then the 3rd IF transformer. Still exactly the same. Then the oscillator transformer. Then finally the antenna transformer plus I realigned everything. I get a nice clear sound exactly the same with the 650 and 700 mixed (only stations received) on 2 places mid dial. I've eliminated about everything, what else could it be?? Im about to sell the whole project!

5/10/2003 1:22:22 PMtundrahawk

:
:
:Hi again, I'm testing the mica caps around the XXD. l These are brown, that means something? Arn't they in pico farads? My Fluke only tests to nano farads. The mica's I'm testing don't even come up on my nano scale. Do I just replace them and test the set?Ck'd voltages. Got 45v on the plate where it should be 85v DC and 49 on the plate supposed to be 75v. Resistors test ok around the XXD tube.
T.
:
::Hi
::
:: Use the DC setting on your meter. Negative to B-, usually negative side of filter caps. Tube plates should be positive.
::
::Norm
::
:::Hi again, I get no sound from the 2nd radio at 455KC so maybe that's it. Ck'd all the resistors except the mica's. Will do that. Need a primer on cking voltages. Do that on AC? and use the neg. input as ground, not the chassis? Tks, T.
:::
::::I agree with Norm's reply. I just conquered a 42-327 with a weak oscillator. When it wasn't osc'ing the one local station would bleed thru slightly all across the dial with certain definite peaks.
::::My problem was the result of a bad mica cap in the XXD osc circuit that I had skipped over umpteen times.
::::-Bill
::::
::::
:::::Hi
:::::
::::: Probably your oscillator isn't operating? Check voltages around your XXD tube. See if you hear the oscillator in a second radio tuned 455KC above your Philco.
:::::
:::::Norm
:::::
::::::This one has really got me! The 41-231 is the pushbutton version of the old 41-221 with the handle and the plastic grill that sags form heat and age. After I cranked up the radio and put in good tubes it would receive 650 and 700 MC simultaneously in 2 areas of the variable tuner. I replaced all the caps and filters, even the speaker and got clear sound but still the same simultaneous reception in two places. I had an old 221 for parts so I replaced the first IF transformer. No change. Then the 2nd IF, no change, then the 3rd IF transformer. Still exactly the same. Then the oscillator transformer. Then finally the antenna transformer plus I realigned everything. I get a nice clear sound exactly the same with the 650 and 700 mixed (only stations received) on 2 places mid dial. I've eliminated about everything, what else could it be?? Im about to sell the whole project!

5/11/2003 8:00:30 AMNorm Leal

Those small mica caps are in pf and probably too low a value to read on your tester. If you don't find anything else wrong you might want to change a mica cap in your osc circuit? Save the original.

Low plate voltage indicates the oscillator isn't operating. When it does run, grid voltage will go negative, causing a tube to draw less current and making plate voltage higher.

The 85 volts is plate on your oscillator section of the XXD. Be sure resistor #27, 10K, isn't high in value. Have you tried another XXD (14AF7)? Resistor #21 and #22 within tolerance? Be sure paper caps around the XXD have been replaced. After that mica caps #12 & #13.

Norm

::
::
::Hi again, I'm testing the mica caps around the XXD. l These are brown, that means something? Arn't they in pico farads? My Fluke only tests to nano farads. The mica's I'm testing don't even come up on my nano scale. Do I just replace them and test the set?Ck'd voltages. Got 45v on the plate where it should be 85v DC and 49 on the plate supposed to be 75v. Resistors test ok around the XXD tube.
: T.
::
:::Hi
:::
::: Use the DC setting on your meter. Negative to B-, usually negative side of filter caps. Tube plates should be positive.
:::
:::Norm
:::
::::Hi again, I get no sound from the 2nd radio at 455KC so maybe that's it. Ck'd all the resistors except the mica's. Will do that. Need a primer on cking voltages. Do that on AC? and use the neg. input as ground, not the chassis? Tks, T.
::::
:::::I agree with Norm's reply. I just conquered a 42-327 with a weak oscillator. When it wasn't osc'ing the one local station would bleed thru slightly all across the dial with certain definite peaks.
:::::My problem was the result of a bad mica cap in the XXD osc circuit that I had skipped over umpteen times.
:::::-Bill
:::::
:::::
::::::Hi
::::::
:::::: Probably your oscillator isn't operating? Check voltages around your XXD tube. See if you hear the oscillator in a second radio tuned 455KC above your Philco.
::::::
::::::Norm
::::::
:::::::This one has really got me! The 41-231 is the pushbutton version of the old 41-221 with the handle and the plastic grill that sags form heat and age. After I cranked up the radio and put in good tubes it would receive 650 and 700 MC simultaneously in 2 areas of the variable tuner. I replaced all the caps and filters, even the speaker and got clear sound but still the same simultaneous reception in two places. I had an old 221 for parts so I replaced the first IF transformer. No change. Then the 2nd IF, no change, then the 3rd IF transformer. Still exactly the same. Then the oscillator transformer. Then finally the antenna transformer plus I realigned everything. I get a nice clear sound exactly the same with the 650 and 700 mixed (only stations received) on 2 places mid dial. I've eliminated about everything, what else could it be?? Im about to sell the whole project!