I've been working on a Crosley 616. It's a 3 band radio and I have the AM and the police band working with good sensitivity. I have nothing on the high frequency band. I have cleaned the contact of the band switch and still have nothing. Any ideas where I should go next?

Hi Dave

Have you tried another 6A8 tube. Oscillator tubes stop operating on higher frequency bands first. Even ones that won't oscillate may test as good.

Measure voltage on grid #1 (pin #5) of the 6A8. It should be negative several volts when oscillating.

Norm

:I've been working on a Crosley 616. It's a 3 band radio and I have the AM and the police band working with good sensitivity. I have nothing on the high frequency band. I have cleaned the contact of the band switch and still have nothing. Any ideas where I should go next?
:

Another though Guys:

This one happened to me. See if the grid clip on top of the tube is properly soldered and is clean making firm contact with the tube. In one case on a Silvertone chassis I had the 6A8 tube stop working due to a dirty and poorly soldered grid clip.

Lou

:Hi Dave
:
: Have you tried another 6A8 tube. Oscillator tubes stop operating on higher frequency bands first. Even ones that won't oscillate may test as good.
:
: Measure voltage on grid #1 (pin #5) of the 6A8. It should be negative several volts when oscillating.
:
:Norm
:
:
::I've been working on a Crosley 616. It's a 3 band radio and I have the AM and the police band working with good sensitivity. I have nothing on the high frequency band. I have cleaned the contact of the band switch and still have nothing. Any ideas where I should go next?
::
:
:

:Hi Dave
:
: Have you tried another 6A8 tube. Oscillator tubes stop operating on higher frequency bands first. Even ones that won't oscillate may test as good.
:
: Measure voltage on grid #1 (pin #5) of the 6A8. It should be negative several volts when oscillating.
:
:Norm
:
:
::I've been working on a Crosley 616. It's a 3 band radio and I have the AM and the police band working with good sensitivity. I have nothing on the high frequency band. I have cleaned the contact of the band switch and still have nothing. Any ideas where I should go next?
::
:
:
Norm,

I have negative voltage at grid #1 for AM and the police band but the high fequency band is positive. I've trined several NOS 6A8's with no change.

Has this unit been completely recapped?

Lou

::Hi Dave
::
:: Have you tried another 6A8 tube. Oscillator tubes stop operating on higher frequency bands first. Even ones that won't oscillate may test as good.
::
:: Measure voltage on grid #1 (pin #5) of the 6A8. It should be negative several volts when oscillating.
::
::Norm
::
::
:::I've been working on a Crosley 616. It's a 3 band radio and I have the AM and the police band working with good sensitivity. I have nothing on the high frequency band. I have cleaned the contact of the band switch and still have nothing. Any ideas where I should go next?
:::
::
::
:Norm,
:
:I have negative voltage at grid #1 for AM and the police band but the high fequency band is positive. I've trined several NOS 6A8's with no change.
:

:Has this unit been completely recapped?
:
:Lou
:
:::Hi Dave
:::
::: Have you tried another 6A8 tube. Oscillator tubes stop operating on higher frequency bands first. Even ones that won't oscillate may test as good.
:::
::: Measure voltage on grid #1 (pin #5) of the 6A8. It should be negative several volts when oscillating.
:::
:::Norm
:::
:::
::::I've been working on a Crosley 616. It's a 3 band radio and I have the AM and the police band working with good sensitivity. I have nothing on the high frequency band. I have cleaned the contact of the band switch and still have nothing. Any ideas where I should go next?
::::
:::
:::
::Norm,
::
::I have negative voltage at grid #1 for AM and the police band but the high fequency band is positive. I've trined several NOS 6A8's with no change.
::
Lou,

Yes, all but one of the filter caps have been replaced.
:
: