Radiola III again

3/4/2010 4:26:34 PMBob

I guess what I should have said is the cap in the schematic shows it connected to both input terminals of the interstage transformer.(across both terminals) In both of my radio's it is not connected across the input, it is grounded from where it connects to the amplification rotor, opposite of where the 20 volts is fed to the transformer. Is this a error in the schematic? I think so.

Bob

3/4/2010 9:54:19 PMNorm Leal

Bob

I don't have a Radiola III in front of me right now but look closely at the cap. It has two ends and a metal body. I'll open a Radiola III if we can't figure this out.

Official Radio Service Manual by Gernsback shows the same, across terminals.

Norm

:I guess what I should have said is the cap in the schematic shows it connected to both input terminals of the interstage transformer.(across both terminals) In both of my radio's it is not connected across the input, it is grounded from where it connects to the amplification rotor, opposite of where the 20 volts is fed to the transformer. Is this a error in the schematic? I think so.
:
:Bob
:

3/5/2010 4:02:42 AMBob

:Bob
:
: I don't have a Radiola III in front of me right now but look closely at the cap. It has two ends and a metal body. I'll open a Radiola III if we can't figure this out.
:
: Official Radio Service Manual by Gernsback shows the same, across terminals.
:
:Norm
:
::I guess what I should have said is the cap in the schematic shows it connected to both input terminals of the interstage transformer.(across both terminals) In both of my radio's it is not connected across the input, it is grounded from where it connects to the amplification rotor, opposite of where the 20 volts is fed to the transformer. Is this a error in the schematic? I think so.
::
::Bob
::
Norm,
I would appreciate if you would check your Radiola III
Im sure Im right and there is a mistake in the schematic that probably has been carried through for around 86 odd years

Bob

3/5/2010 12:22:18 PMNorm Leal

Hi Bob

Interesting. There are a couple ways this capacitor is mounted. One way like the schematic, right across the interstage transformer. The other way it's mounted on metal frame with only one connection to the audio interstage transformer.

Electrically it doesn't matter where the cap is connected. As long as one side goes back to some battery should be ok. AC wise all batteries should be about the same. One of my caps is marked with a value .0008. So even that doesn't exactly match the schematic.

Never noticed this difference before but there are others. Not all Radiola III use those drum caps. Some levers on top have a hole for a finger others have that little black knob. This is the biggest noticeable difference.

Norm

::Bob
::
:: I don't have a Radiola III in front of me right now but look closely at the cap. It has two ends and a metal body. I'll open a Radiola III if we can't figure this out.
::
:: Official Radio Service Manual by Gernsback shows the same, across terminals.
::
::Norm
::
:::I guess what I should have said is the cap in the schematic shows it connected to both input terminals of the interstage transformer.(across both terminals) In both of my radio's it is not connected across the input, it is grounded from where it connects to the amplification rotor, opposite of where the 20 volts is fed to the transformer. Is this a error in the schematic? I think so.
:::
:::Bob
:::
:Norm,
:I would appreciate if you would check your Radiola III
:Im sure Im right and there is a mistake in the schematic that probably has been carried through for around 86 odd years
:
:Bob
:

3/5/2010 5:29:36 PMBob

:Hi Bob
:
: Interesting. There are a couple ways this capacitor is mounted. One way like the schematic, right across the interstage transformer. The other way it's mounted on metal frame with only one connection to the audio interstage transformer.
:
: Electrically it doesn't matter where the cap is connected. As long as one side goes back to some battery should be ok. AC wise all batteries should be about the same. One of my caps is marked with a value .0008. So even that doesn't exactly match the schematic.
:
: Never noticed this difference before but there are others. Not all Radiola III use those drum caps. Some levers on top have a hole for a finger others have that little black knob. This is the biggest noticeable difference.
:
:Norm
:
:
:
:::Bob
:::
::: I don't have a Radiola III in front of me right now but look closely at the cap. It has two ends and a metal body. I'll open a Radiola III if we can't figure this out.
:::
::: Official Radio Service Manual by Gernsback shows the same, across terminals.
:::
:::Norm
:::
::::I guess what I should have said is the cap in the schematic shows it connected to both input terminals of the interstage transformer.(across both terminals) In both of my radio's it is not connected across the input, it is grounded from where it connects to the amplification rotor, opposite of where the 20 volts is fed to the transformer. Is this a error in the schematic? I think so.
::::
::::Bob
::::
::Norm,
::I would appreciate if you would check your Radiola III
::Im sure Im right and there is a mistake in the schematic that probably has been carried through for around 86 odd years
::
::Bob
::
Thanks Norm, This clears up the mystery for me.

Bob