What could cause a hum on the radio? Where would be the first place to look? The hum gets louder as I turn the detector knob up. Haven't picked up any staions yet. But that could be either I haven't tuned 1 in yet. Or, something needs to be done. thanks

Jack

Important to have a well filtered filament (A) supply. If not filtered well turning up volume will increase hum.

Also be sure the grid side of an audio interstage transformer isn't open.

Norm

:What could cause a hum on the radio? Where would be the first place to look? The hum gets louder as I turn the detector knob up. Haven't picked up any staions yet. But that could be either I haven't tuned 1 in yet. Or, something needs to be done. thanks
:

:Jack
:
: Important to have a well filtered filament (A) supply. If not filtered well turning up volume will increase hum.
:
: Also be sure the grid side of an audio interstage transformer isn't open.
:
:Norm
:
::What could cause a hum on the radio? Where would be the first place to look? The hum gets louder as I turn the detector knob up. Haven't picked up any staions yet. But that could be either I haven't tuned 1 in yet. Or, something needs to be done. thanks
::
:
You also need a well filtered B supply as well. Check your filter caps, clip in substitute caps for each filter. You need a good power supply before you can really do any meaningful troubleshooting.
Lewis

::Jack
::
:: Important to have a well filtered filament (A) supply. If not filtered well turning up volume will increase hum.
::
:: Also be sure the grid side of an audio interstage transformer isn't open.
::
::Norm
::
:::What could cause a hum on the radio? Where would be the first place to look? The hum gets louder as I turn the detector knob up. Haven't picked up any staions yet. But that could be either I haven't tuned 1 in yet. Or, something needs to be done. thanks
:::
::
:You also need a well filtered B supply as well. Check your filter caps, clip in substitute caps for each filter. You need a good power supply before you can really do any meaningful troubleshooting.
:Lewis
:

Thanks.
Using a battery eliminator that works well. I took out a tube, put it back in and now. tubes don't light up and no voltage on the plate contact of tube base 1. The others do have voltage.
:

This is where I am now. Found out the hum was because the BE was too close. Have replaced the 3 resistors on top of the chassis with 4k.That was what was printed on the old ones. have a 2.2 UF cap to replace the bypass cap. Now, when I turn dials 2 and 3. I get a click, click-click noise haven't picked up any stations yet, though.
thanks

:::Jack
:::
::: Important to have a well filtered filament (A) supply. If not filtered well turning up volume will increase hum.
:::
::: Also be sure the grid side of an audio interstage transformer isn't open.
:::
:::Norm
:::
::::What could cause a hum on the radio? Where would be the first place to look? The hum gets louder as I turn the detector knob up. Haven't picked up any staions yet. But that could be either I haven't tuned 1 in yet. Or, something needs to be done. thanks
::::
:::
::You also need a well filtered B supply as well. Check your filter caps, clip in substitute caps for each filter. You need a good power supply before you can really do any meaningful troubleshooting.
::Lewis
::
:
:Thanks.
:Using a battery eliminator that works well. I took out a tube, put it back in and now. tubes don't light up and no voltage on the plate contact of tube base 1. The others do have voltage.
::
:
: