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General Electric E-76
10/7/2006 7:03:07 PMTerry
I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?

As always, any help is greatly appreciated.

Terry

10/7/2006 7:50:49 PMNorm Leal
Hi Tony

A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.

Norm

:I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
:
:As always, any help is greatly appreciated.
:
:Terry

10/7/2006 9:52:48 PMTerry
:Hi Tony
:
: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
:
:Norm

Thank you for the information. I have to get another cap.

Terry
:
:
:
::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
::
::As always, any help is greatly appreciated.
::
::Terry

10/14/2006 1:26:03 PMTerry
Norm,
I replaced the cap and (in the meantime) I found there was no ground wire from the resistor bar to the chassis. I installed the wire, replaced the 16mfd cap and there still isn't any sound.

Terry
::Hi Tony
::
:: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
::
::Norm
:
:Thank you for the information. I have to get another cap.
:
:Terry
::
::
::
:::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
:::
:::As always, any help is greatly appreciated.
:::
:::Terry

10/14/2006 1:24:02 PMTerry
:Hi Tony
:
: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
:
:Norm
:
:
:
::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
::
::As always, any help is greatly appreciated.
::
::Terry
10/16/2006 6:55:19 PMTerry F
Norm,
I replaced the cap, attached the missing ground wire from the resistor bar (previous e-mail) and now I have a hum at the speaker with no sound. My next step is to verify the voltages. Other options?

Terry F

:Hi Tony
:
: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
:
:Norm
:
:
:
::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
::
::As always, any help is greatly appreciated.
::
::Terry

10/16/2006 7:02:04 PMNorm Leal
Terry

Only slight hum may be normal. If loud check electrolytic cap connections.

Right, measuring plate & grid 2 voltages would be a good next step.

Norm

:Norm,
:I replaced the cap, attached the missing ground wire from the resistor bar (previous e-mail) and now I have a hum at the speaker with no sound. My next step is to verify the voltages. Other options?
:
:Terry F
:
::Hi Tony
::
:: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
::
::Norm
::
::
::
:::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
:::
:::As always, any help is greatly appreciated.
:::
:::Terry

10/16/2006 9:47:05 PMTerry F
:Terry
:
: Only slight hum may be normal. If loud check electrolytic cap connections.
:
: Right, measuring plate & grid 2 voltages would be a good next step.
:
:Norm
:
::Norm,
::I replaced the cap, attached the missing ground wire from the resistor bar (previous e-mail) and now I have a hum at the speaker with no sound. My next step is to verify the voltages. Other options?
::
::Terry F
::
:::Hi Tony
:::
::: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
:::
:::Norm
:::
::: Norm,

Voltages were screwy, so I retested the tubes and found the 5W4 shorted. I'll get a new one and then check voltages again.

Thanks for your advise and help.

Terry F
:::
::::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
::::
::::As always, any help is greatly appreciated.
::::
::::Terry

10/23/2006 7:26:26 PMTerry F
:Norm,

The 5W4 was replaced and I now get a faint sound on stations in the 550 and 1100 range. What am I overlooking?

Terry F
:
: Only slight hum may be normal. If loud check electrolytic cap connections.
:
: Right, measuring plate & grid 2 voltages would be a good next step.
:
:Norm
:
::Norm,
::I replaced the cap, attached the missing ground wire from the resistor bar (previous e-mail) and now I have a hum at the speaker with no sound. My next step is to verify the voltages. Other options?
::
::Terry F
::
:::Hi Tony
:::
::: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
:::
:::Norm
:::
:::
:::
::::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
::::
::::As always, any help is greatly appreciated.
::::
::::Terry

10/24/2006 1:11:16 PMNorm Leal
Terry

Do you hear loud hum touching the top connection on your 6F5 tube? If so the audio circuit is operating properly.

Do you have an antenna connected? A wire 10-20 feet will work ok.

http://www.nostalgiaair.org/PagesByModel/783/M0007783.pdf

If you have a meter measure voltages on plates & screen (G2) of your tubes.

Norm

::Norm,
:
:The 5W4 was replaced and I now get a faint sound on stations in the 550 and 1100 range. What am I overlooking?
:
:Terry F
::
:: Only slight hum may be normal. If loud check electrolytic cap connections.
::
:: Right, measuring plate & grid 2 voltages would be a good next step.
::
::Norm
::
:::Norm,
:::I replaced the cap, attached the missing ground wire from the resistor bar (previous e-mail) and now I have a hum at the speaker with no sound. My next step is to verify the voltages. Other options?
:::
:::Terry F
:::
::::Hi Tony
::::
:::: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
::::
::::Norm
::::
::::
::::
:::::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
:::::
:::::As always, any help is greatly appreciated.
:::::
:::::Terry

10/24/2006 9:21:12 PMTerry F - Not the Other Terry
Norm,

No hum when touching the top of the driver 6F5.
I did connect an antenna (20 ft. or so) and the sound improved slightly.

On the 6F6 here is what I got:
Heaters = 6.22VAC
P = 212VDC
G2 = 258VDC
G1 = 9.8VDC

I will check the 6F5 tomorrow.

Terry F

:Terry
:
: Do you hear loud hum touching the top connection on your 6F5 tube? If so the audio circuit is operating properly.
:
: Do you have an antenna connected? A wire 10-20 feet will work ok.
:
:http://www.nostalgiaair.org/PagesByModel/783/M0007783.pdf
:
: If you have a meter measure voltages on plates & screen (G2) of your tubes.
:
:Norm
:
:
:
:::Norm,
::
::The 5W4 was replaced and I now get a faint sound on stations in the 550 and 1100 range. What am I overlooking?
::
::Terry F
:::
::: Only slight hum may be normal. If loud check electrolytic cap connections.
:::
::: Right, measuring plate & grid 2 voltages would be a good next step.
:::
:::Norm
:::
::::Norm,
::::I replaced the cap, attached the missing ground wire from the resistor bar (previous e-mail) and now I have a hum at the speaker with no sound. My next step is to verify the voltages. Other options?
::::
::::Terry F
::::
:::::Hi Tony
:::::
::::: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
:::::
:::::Norm
:::::
:::::
:::::
::::::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
::::::
::::::As always, any help is greatly appreciated.
::::::
::::::Terry

10/24/2006 10:36:32 PMNorm Leal
Hi Terry F

G1 should not be about 15 volts Negative, not positive. Replace cap C20, .005 mf to pin #5 on your 6F6. Measure resistor R12. If high use a lower value such as 330K instead of 470K.

Since you don't hear a loud hum touching top of your 6F5 problem is in the audio section.

Norm

:Norm,
:
:No hum when touching the top of the driver 6F5.
:I did connect an antenna (20 ft. or so) and the sound improved slightly.
:
:On the 6F6 here is what I got:
:Heaters = 6.22VAC
:P = 212VDC
:G2 = 258VDC
:G1 = 9.8VDC
:
:I will check the 6F5 tomorrow.
:
:Terry F
:
:
:
:
:
::Terry
::
:: Do you hear loud hum touching the top connection on your 6F5 tube? If so the audio circuit is operating properly.
::
:: Do you have an antenna connected? A wire 10-20 feet will work ok.
::
::http://www.nostalgiaair.org/PagesByModel/783/M0007783.pdf
::
:: If you have a meter measure voltages on plates & screen (G2) of your tubes.
::
::Norm
::
::
::
::::Norm,
:::
:::The 5W4 was replaced and I now get a faint sound on stations in the 550 and 1100 range. What am I overlooking?
:::
:::Terry F
::::
:::: Only slight hum may be normal. If loud check electrolytic cap connections.
::::
:::: Right, measuring plate & grid 2 voltages would be a good next step.
::::
::::Norm
::::
:::::Norm,
:::::I replaced the cap, attached the missing ground wire from the resistor bar (previous e-mail) and now I have a hum at the speaker with no sound. My next step is to verify the voltages. Other options?
:::::
:::::Terry F
:::::
::::::Hi Tony
::::::
:::::: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
::::::
::::::Norm
::::::
::::::
::::::
:::::::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
:::::::
:::::::As always, any help is greatly appreciated.
:::::::
:::::::Terry

10/25/2006 12:33:44 PMTerry F
:Norm,

My mistake, the voltage is negative (- 9.8VDC).

Should I still replace the components?

Terry F - From St. Louis - Go Cards!

Hi Terry F
:
: G1 should not be about 15 volts Negative, not positive. Replace cap C20, .005 mf to pin #5 on your 6F6. Measure resistor R12. If high use a lower value such as 330K instead of 470K.
:
: Since you don't hear a loud hum touching top of your 6F5 problem is in the audio section.
:
:Norm
:
:
:
::Norm,
::
::No hum when touching the top of the driver 6F5.
::I did connect an antenna (20 ft. or so) and the sound improved slightly.
::
::On the 6F6 here is what I got:
::Heaters = 6.22VAC
::P = 212VDC
::G2 = 258VDC
::G1 = 9.8VDC
::
::I will check the 6F5 tomorrow.
::
::Terry F
::
::
::
::
::
:::Terry
:::
::: Do you hear loud hum touching the top connection on your 6F5 tube? If so the audio circuit is operating properly.
:::
::: Do you have an antenna connected? A wire 10-20 feet will work ok.
:::
:::http://www.nostalgiaair.org/PagesByModel/783/M0007783.pdf
:::
::: If you have a meter measure voltages on plates & screen (G2) of your tubes.
:::
:::Norm
:::
:::
:::
:::::Norm,
::::
::::The 5W4 was replaced and I now get a faint sound on stations in the 550 and 1100 range. What am I overlooking?
::::
::::Terry F
:::::
::::: Only slight hum may be normal. If loud check electrolytic cap connections.
:::::
::::: Right, measuring plate & grid 2 voltages would be a good next step.
:::::
:::::Norm
:::::
::::::Norm,
::::::I replaced the cap, attached the missing ground wire from the resistor bar (previous e-mail) and now I have a hum at the speaker with no sound. My next step is to verify the voltages. Other options?
::::::
::::::Terry F
::::::
:::::::Hi Tony
:::::::
::::::: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
:::::::
:::::::Norm
:::::::
:::::::
:::::::
::::::::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
::::::::
::::::::As always, any help is greatly appreciated.
::::::::
::::::::Terry

10/25/2006 2:22:43 PMNorm Leal
Terry F

No, negative 9.8 volts is reasonable. You should still hear loud hum touching top of the 6F5. Check pin #4 on this tube. It should be positive. Your 6F6 has proper voltages.

Norm

::Norm,
:
:My mistake, the voltage is negative (- 9.8VDC).
:
:Should I still replace the components?
:
:Terry F - From St. Louis - Go Cards!
:
:Hi Terry F
::
:: G1 should not be about 15 volts Negative, not positive. Replace cap C20, .005 mf to pin #5 on your 6F6. Measure resistor R12. If high use a lower value such as 330K instead of 470K.
::
:: Since you don't hear a loud hum touching top of your 6F5 problem is in the audio section.
::
::Norm
::
::
::
:::Norm,
:::
:::No hum when touching the top of the driver 6F5.
:::I did connect an antenna (20 ft. or so) and the sound improved slightly.
:::
:::On the 6F6 here is what I got:
:::Heaters = 6.22VAC
:::P = 212VDC
:::G2 = 258VDC
:::G1 = 9.8VDC
:::
:::I will check the 6F5 tomorrow.
:::
:::Terry F
:::
:::
:::
:::
:::
::::Terry
::::
:::: Do you hear loud hum touching the top connection on your 6F5 tube? If so the audio circuit is operating properly.
::::
:::: Do you have an antenna connected? A wire 10-20 feet will work ok.
::::
::::http://www.nostalgiaair.org/PagesByModel/783/M0007783.pdf
::::
:::: If you have a meter measure voltages on plates & screen (G2) of your tubes.
::::
::::Norm
::::
::::
::::
::::::Norm,
:::::
:::::The 5W4 was replaced and I now get a faint sound on stations in the 550 and 1100 range. What am I overlooking?
:::::
:::::Terry F
::::::
:::::: Only slight hum may be normal. If loud check electrolytic cap connections.
::::::
:::::: Right, measuring plate & grid 2 voltages would be a good next step.
::::::
::::::Norm
::::::
:::::::Norm,
:::::::I replaced the cap, attached the missing ground wire from the resistor bar (previous e-mail) and now I have a hum at the speaker with no sound. My next step is to verify the voltages. Other options?
:::::::
:::::::Terry F
:::::::
::::::::Hi Tony
::::::::
:::::::: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
::::::::
::::::::Norm
::::::::
::::::::
::::::::
:::::::::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
:::::::::
:::::::::As always, any help is greatly appreciated.
:::::::::
:::::::::Terry

10/25/2006 6:38:14 PMTerry F
Norm,

Pin #4 is "P" that I see and it has 242 VDC (not 60VDC) as noted on the schematic.

When I touch the pin with the meter lead it crackles quite loudly.

Terry F


Terry F
:
: No, negative 9.8 volts is reasonable. You should still hear loud hum touching top of the 6F5. Check pin #4 on this tube. It should be positive. Your 6F6 has proper voltages.
:
:Norm
:
:::Norm,
::
::My mistake, the voltage is negative (- 9.8VDC).
::
::Should I still replace the components?
::
::Terry F - From St. Louis - Go Cards!
::
::Hi Terry F
:::
::: G1 should not be about 15 volts Negative, not positive. Replace cap C20, .005 mf to pin #5 on your 6F6. Measure resistor R12. If high use a lower value such as 330K instead of 470K.
:::
::: Since you don't hear a loud hum touching top of your 6F5 problem is in the audio section.
:::
:::Norm
:::
:::
:::
::::Norm,
::::
::::No hum when touching the top of the driver 6F5.
::::I did connect an antenna (20 ft. or so) and the sound improved slightly.
::::
::::On the 6F6 here is what I got:
::::Heaters = 6.22VAC
::::P = 212VDC
::::G2 = 258VDC
::::G1 = 9.8VDC
::::
::::I will check the 6F5 tomorrow.
::::
::::Terry F
::::
::::
::::
::::
::::
:::::Terry
:::::
::::: Do you hear loud hum touching the top connection on your 6F5 tube? If so the audio circuit is operating properly.
:::::
::::: Do you have an antenna connected? A wire 10-20 feet will work ok.
:::::
:::::http://www.nostalgiaair.org/PagesByModel/783/M0007783.pdf
:::::
::::: If you have a meter measure voltages on plates & screen (G2) of your tubes.
:::::
:::::Norm
:::::
:::::
:::::
:::::::Norm,
::::::
::::::The 5W4 was replaced and I now get a faint sound on stations in the 550 and 1100 range. What am I overlooking?
::::::
::::::Terry F
:::::::
::::::: Only slight hum may be normal. If loud check electrolytic cap connections.
:::::::
::::::: Right, measuring plate & grid 2 voltages would be a good next step.
:::::::
:::::::Norm
:::::::
::::::::Norm,
::::::::I replaced the cap, attached the missing ground wire from the resistor bar (previous e-mail) and now I have a hum at the speaker with no sound. My next step is to verify the voltages. Other options?
::::::::
::::::::Terry F
::::::::
:::::::::Hi Tony
:::::::::
::::::::: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
:::::::::
:::::::::Norm
:::::::::
:::::::::
:::::::::
::::::::::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
::::::::::
::::::::::As always, any help is greatly appreciated.
::::::::::
::::::::::Terry

10/25/2006 8:37:20 PMNorm Leal
Hi Terry F

You will read higher voltage. Modern meters don't load down the circuit as much.

You hear noise at pin #4, plate but not at grid #1 (top cap). Can you test the 6F5? Do you have a replacement? Do you have any other tubes?

Norm

:Norm,
:
:Pin #4 is "P" that I see and it has 242 VDC (not 60VDC) as noted on the schematic.
:
:When I touch the pin with the meter lead it crackles quite loudly.
:
:Terry F
:
:
:Terry F
::
:: No, negative 9.8 volts is reasonable. You should still hear loud hum touching top of the 6F5. Check pin #4 on this tube. It should be positive. Your 6F6 has proper voltages.
::
::Norm
::
::::Norm,
:::
:::My mistake, the voltage is negative (- 9.8VDC).
:::
:::Should I still replace the components?
:::
:::Terry F - From St. Louis - Go Cards!
:::
:::Hi Terry F
::::
:::: G1 should not be about 15 volts Negative, not positive. Replace cap C20, .005 mf to pin #5 on your 6F6. Measure resistor R12. If high use a lower value such as 330K instead of 470K.
::::
:::: Since you don't hear a loud hum touching top of your 6F5 problem is in the audio section.
::::
::::Norm
::::
::::
::::
:::::Norm,
:::::
:::::No hum when touching the top of the driver 6F5.
:::::I did connect an antenna (20 ft. or so) and the sound improved slightly.
:::::
:::::On the 6F6 here is what I got:
:::::Heaters = 6.22VAC
:::::P = 212VDC
:::::G2 = 258VDC
:::::G1 = 9.8VDC
:::::
:::::I will check the 6F5 tomorrow.
:::::
:::::Terry F
:::::
:::::
:::::
:::::
:::::
::::::Terry
::::::
:::::: Do you hear loud hum touching the top connection on your 6F5 tube? If so the audio circuit is operating properly.
::::::
:::::: Do you have an antenna connected? A wire 10-20 feet will work ok.
::::::
::::::http://www.nostalgiaair.org/PagesByModel/783/M0007783.pdf
::::::
:::::: If you have a meter measure voltages on plates & screen (G2) of your tubes.
::::::
::::::Norm
::::::
::::::
::::::
::::::::Norm,
:::::::
:::::::The 5W4 was replaced and I now get a faint sound on stations in the 550 and 1100 range. What am I overlooking?
:::::::
:::::::Terry F
::::::::
:::::::: Only slight hum may be normal. If loud check electrolytic cap connections.
::::::::
:::::::: Right, measuring plate & grid 2 voltages would be a good next step.
::::::::
::::::::Norm
::::::::
:::::::::Norm,
:::::::::I replaced the cap, attached the missing ground wire from the resistor bar (previous e-mail) and now I have a hum at the speaker with no sound. My next step is to verify the voltages. Other options?
:::::::::
:::::::::Terry F
:::::::::
::::::::::Hi Tony
::::::::::
:::::::::: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
::::::::::
::::::::::Norm
::::::::::
::::::::::
::::::::::
:::::::::::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
:::::::::::
:::::::::::As always, any help is greatly appreciated.
:::::::::::
:::::::::::Terry

10/26/2006 8:18:07 PMTerry F
:Norm,

You are brilliant. I had a spare tube and it works!
Thank you very, very much!

Terry F

Hi Terry F
:
: You will read higher voltage. Modern meters don't load down the circuit as much.
:
: You hear noise at pin #4, plate but not at grid #1 (top cap). Can you test the 6F5? Do you have a replacement? Do you have any other tubes?
:
:Norm
:
::Norm,
::
::Pin #4 is "P" that I see and it has 242 VDC (not 60VDC) as noted on the schematic.
::
::When I touch the pin with the meter lead it crackles quite loudly.
::
::Terry F
::
::
::Terry F
:::
::: No, negative 9.8 volts is reasonable. You should still hear loud hum touching top of the 6F5. Check pin #4 on this tube. It should be positive. Your 6F6 has proper voltages.
:::
:::Norm
:::
:::::Norm,
::::
::::My mistake, the voltage is negative (- 9.8VDC).
::::
::::Should I still replace the components?
::::
::::Terry F - From St. Louis - Go Cards!
::::
::::Hi Terry F
:::::
::::: G1 should not be about 15 volts Negative, not positive. Replace cap C20, .005 mf to pin #5 on your 6F6. Measure resistor R12. If high use a lower value such as 330K instead of 470K.
:::::
::::: Since you don't hear a loud hum touching top of your 6F5 problem is in the audio section.
:::::
:::::Norm
:::::
:::::
:::::
::::::Norm,
::::::
::::::No hum when touching the top of the driver 6F5.
::::::I did connect an antenna (20 ft. or so) and the sound improved slightly.
::::::
::::::On the 6F6 here is what I got:
::::::Heaters = 6.22VAC
::::::P = 212VDC
::::::G2 = 258VDC
::::::G1 = 9.8VDC
::::::
::::::I will check the 6F5 tomorrow.
::::::
::::::Terry F
::::::
::::::
::::::
::::::
::::::
:::::::Terry
:::::::
::::::: Do you hear loud hum touching the top connection on your 6F5 tube? If so the audio circuit is operating properly.
:::::::
::::::: Do you have an antenna connected? A wire 10-20 feet will work ok.
:::::::
:::::::http://www.nostalgiaair.org/PagesByModel/783/M0007783.pdf
:::::::
::::::: If you have a meter measure voltages on plates & screen (G2) of your tubes.
:::::::
:::::::Norm
:::::::
:::::::
:::::::
:::::::::Norm,
::::::::
::::::::The 5W4 was replaced and I now get a faint sound on stations in the 550 and 1100 range. What am I overlooking?
::::::::
::::::::Terry F
:::::::::
::::::::: Only slight hum may be normal. If loud check electrolytic cap connections.
:::::::::
::::::::: Right, measuring plate & grid 2 voltages would be a good next step.
:::::::::
:::::::::Norm
:::::::::
::::::::::Norm,
::::::::::I replaced the cap, attached the missing ground wire from the resistor bar (previous e-mail) and now I have a hum at the speaker with no sound. My next step is to verify the voltages. Other options?
::::::::::
::::::::::Terry F
::::::::::
:::::::::::Hi Tony
:::::::::::
::::::::::: A 16 mf cap is electrolytic. It has positive and negative leads. If reversed it will blow. Positive connects to the filament of 5W4 rectifier tube. Be sure it is in the proper direction and has a voltage rating of 450 or at least as high as original.
:::::::::::
:::::::::::Norm
:::::::::::
:::::::::::
:::::::::::
::::::::::::I need some help here if possible: I recapped this radio and replaced the defecive tubes. Rider GE Page 7-13. The unit powers up, tube heaters glow, but no sound. C1 (16mfd) has blown twice. Advise?
::::::::::::
::::::::::::As always, any help is greatly appreciated.
::::::::::::
::::::::::::Terry

10/25/2006 8:10:37 PMrghines1
Serviced this same radio about a year ago. Real nightmare with the crumbling rubber insulation. This radio was the equal of those Peter's repair adventure stories he posts every month or so. One wire connected underneath to the ganged tuning cap was making solid contact to the chassis through the rubber insulation and could only hear one strong station. Better stop now before this becomes a rant. Sir, you have my sympathy!

Richard



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