I just recapped this radio and it plays, but does not have much volume and has a little static. This occurs with or w/o the antenna wire hooked up to the clip in the rear of the chassis. (Usually when I connect the antenna to any radio, it receives stations much louder and clearer.)
When I touch the 1Det (77) tube with the tip of my soldering iron, it plays loud and clear the way I would expect it to play after hooking up the antenna wire.
I checked the antenna coils before the RF amp and they are showing continuity as well as the coil before the 1 Det. No opens. Going back and touching the plate of the 78 and either side of the 110 mmf capacitor just prior to the 77 tube with the iron gets great reception as well. I am not sure what to troubleshoot from here. I know the problem must be prior to this 110 mmf capacitor, but have no idea where. Any help would be appreciated.
Thanks,
Steve
Check pin #2 and #3 voltage on the RF #78 tube. One of these voltages may be missing? The coil which supplies voltage to plate of RF 78 may be open?
You were right to check coils. If a winding is open the radio would act the same way.
Norm
:Happy New Year,
:
:I just recapped this radio and it plays, but does not have much volume and has a little static. This occurs with or w/o the antenna wire hooked up to the clip in the rear of the chassis. (Usually when I connect the antenna to any radio, it receives stations much louder and clearer.)
:When I touch the 1Det (77) tube with the tip of my soldering iron, it plays loud and clear the way I would expect it to play after hooking up the antenna wire.
:
:I checked the antenna coils before the RF amp and they are showing continuity as well as the coil before the 1 Det. No opens. Going back and touching the plate of the 78 and either side of the 110 mmf capacitor just prior to the 77 tube with the iron gets great reception as well. I am not sure what to troubleshoot from here. I know the problem must be prior to this 110 mmf capacitor, but have no idea where. Any help would be appreciated.
:
:Thanks,
:
:Steve
:
Happy New Year to you, too.
I did a voltage check and have the following:
78 tube: P2-P5=4.5VDC; P3-P5=2.5VDC; P2-P3=145VDC; P4-P5=-26VDC; P2-GridCap=233VDC. The volume increases when I touch the plate of this tube with my voltmeter probe. Prior to that pin, no change in volume.
77 tube: P2-P5=233VDC; P5-G1=-7VDC; P2-P3=152VDC; P4-P5=-11mvDC; P3-P5=82VDC.
The antenna coils is not open. It measures 6 ohms from the grid of the 78 to resistor numbber 10 (1000 ohms)on the schmatic.
Thanks,
Steve
:Steve
:
: Check pin #2 and #3 voltage on the RF #78 tube. One of these voltages may be missing? The coil which supplies voltage to plate of RF 78 may be open?
:
: You were right to check coils. If a winding is open the radio would act the same way.
:
:Norm
:
::Happy New Year,
::
::I just recapped this radio and it plays, but does not have much volume and has a little static. This occurs with or w/o the antenna wire hooked up to the clip in the rear of the chassis. (Usually when I connect the antenna to any radio, it receives stations much louder and clearer.)
::When I touch the 1Det (77) tube with the tip of my soldering iron, it plays loud and clear the way I would expect it to play after hooking up the antenna wire.
::
::I checked the antenna coils before the RF amp and they are showing continuity as well as the coil before the 1 Det. No opens. Going back and touching the plate of the 78 and either side of the 110 mmf capacitor just prior to the 77 tube with the iron gets great reception as well. I am not sure what to troubleshoot from here. I know the problem must be prior to this 110 mmf capacitor, but have no idea where. Any help would be appreciated.
::
::Thanks,
::
::Steve
::
:
:
Think you found a problem. Pin #2 to pin #5 and pin #3 to #5 should be a lot higher in voltage. Check the cathode resistor to chassis. It may be open. For a test you can connect pin #5 direct to chassis.
At first I wondered about your readings. We usually measure to B- or chassis but your measurements do show a problem.
Norm
:Hi Norm,
:
:Happy New Year to you, too.
:
:I did a voltage check and have the following:
:
:78 tube: P2-P5=4.5VDC; P3-P5=2.5VDC; P2-P3=145VDC; P4-P5=-26VDC; P2-GridCap=233VDC. The volume increases when I touch the plate of this tube with my voltmeter probe. Prior to that pin, no change in volume.
:
:77 tube: P2-P5=233VDC; P5-G1=-7VDC; P2-P3=152VDC; P4-P5=-11mvDC; P3-P5=82VDC.
:
:The antenna coils is not open. It measures 6 ohms from the grid of the 78 to resistor numbber 10 (1000 ohms)on the schmatic.
:
:Thanks,
:Steve
:
::Steve
::
:: Check pin #2 and #3 voltage on the RF #78 tube. One of these voltages may be missing? The coil which supplies voltage to plate of RF 78 may be open?
::
:: You were right to check coils. If a winding is open the radio would act the same way.
::
::Norm
::
:::Happy New Year,
:::
:::I just recapped this radio and it plays, but does not have much volume and has a little static. This occurs with or w/o the antenna wire hooked up to the clip in the rear of the chassis. (Usually when I connect the antenna to any radio, it receives stations much louder and clearer.)
:::When I touch the 1Det (77) tube with the tip of my soldering iron, it plays loud and clear the way I would expect it to play after hooking up the antenna wire.
:::
:::I checked the antenna coils before the RF amp and they are showing continuity as well as the coil before the 1 Det. No opens. Going back and touching the plate of the 78 and either side of the 110 mmf capacitor just prior to the 77 tube with the iron gets great reception as well. I am not sure what to troubleshoot from here. I know the problem must be prior to this 110 mmf capacitor, but have no idea where. Any help would be appreciated.
:::
:::Thanks,
:::
:::Steve
:::
::
::
:
:
I checked that resistor and it was open. I just replaced it, and the radio plays perfectly.
I always learn a lot when I read your posts. Thanks for the help!
Steve
Hi Steve
:
: Think you found a problem. Pin #2 to pin #5 and pin #3 to #5 should be a lot higher in voltage. Check the cathode resistor to chassis. It may be open. For a test you can connect pin #5 direct to chassis.
:
: At first I wondered about your readings. We usually measure to B- or chassis but your measurements do show a problem.
:
:Norm
:
::Hi Norm,
::
::Happy New Year to you, too.
::
::I did a voltage check and have the following:
::
::78 tube: P2-P5=4.5VDC; P3-P5=2.5VDC; P2-P3=145VDC; P4-P5=-26VDC; P2-GridCap=233VDC. The volume increases when I touch the plate of this tube with my voltmeter probe. Prior to that pin, no change in volume.
::
::77 tube: P2-P5=233VDC; P5-G1=-7VDC; P2-P3=152VDC; P4-P5=-11mvDC; P3-P5=82VDC.
::
::The antenna coils is not open. It measures 6 ohms from the grid of the 78 to resistor numbber 10 (1000 ohms)on the schmatic.
::
::Thanks,
::Steve
::
:::Steve
:::
::: Check pin #2 and #3 voltage on the RF #78 tube. One of these voltages may be missing? The coil which supplies voltage to plate of RF 78 may be open?
:::
::: You were right to check coils. If a winding is open the radio would act the same way.
:::
:::Norm
:::
::::Happy New Year,
::::
::::I just recapped this radio and it plays, but does not have much volume and has a little static. This occurs with or w/o the antenna wire hooked up to the clip in the rear of the chassis. (Usually when I connect the antenna to any radio, it receives stations much louder and clearer.)
::::When I touch the 1Det (77) tube with the tip of my soldering iron, it plays loud and clear the way I would expect it to play after hooking up the antenna wire.
::::
::::I checked the antenna coils before the RF amp and they are showing continuity as well as the coil before the 1 Det. No opens. Going back and touching the plate of the 78 and either side of the 110 mmf capacitor just prior to the 77 tube with the iron gets great reception as well. I am not sure what to troubleshoot from here. I know the problem must be prior to this 110 mmf capacitor, but have no idea where. Any help would be appreciated.
::::
::::Thanks,
::::
::::Steve
::::
:::
:::
::
::
:
: