Hello All,
I replaced all the paper and electrolytic capacitors in this set. The tuner is working and the sound is ok but it should be a lot stronger and a lot louder. I checked all the flexible resistors and the fixed resistors but maybe I missed something. The Schematic is on AK page 1-63 of Riders. The tubes test good too. Please help. I'll check all suggestions.

Thanks,

Dave

Like to verify the voltages on the tubes are within reason. Normally they will read about 10% higher with a modern meter and higher mains voltage. Often problems are revealed with simple voltage checks.

Check continuity of the antenna coils.

Next an alignment is recommended given it old age. However a quick look showed no procedure.

Richard

I would check the antenna ckt. When you touch the grid of the 1st det, does the volume increase?

You could try improving the IF alignment with the trimmers.

I noticed there is a detailed voltage table with the schematic. Check all the voltages.

:Hello All,
: I replaced all the paper and electrolytic capacitors in this set. The tuner is working and the sound is ok but it should be a lot stronger and a lot louder. I checked all the flexible resistors and the fixed resistors but maybe I missed something. The Schematic is on AK page 1-63 of Riders. The tubes test good too. Please help. I'll check all suggestions.
:
:Thanks,
:
:Dave
:
Dave,

I restored an AK model 20. I replaced the standard parts, checked tubes and powered the radio up. I received stations with low volume, when touching the long wire antenna i could make the volume go up.

Eventually I found a break in the volume control, after I replaced it the volume worked properly.

Mitch

Mitch,
That "volume" control is not right. However it's not the same as what we call a volume control today. (Will a carbon type work as a replacement?) It's doing something to the "control" tube, adjusting a voltage (the bias voltage). This control tube I'm assuming is an early AVC tube, but somewhat manually controlled by this "volume" control. That's kind of an interesting circuit. It's doing something to the cathode of the control tube and then the control tube, in turn, is doing something to the cathode of the second detector tube to adjust the bias and change the volume. Very interesting, but I'm not sure I totally understand how it works.

Thanks,

Dave
::Hello All,
:: I replaced all the paper and electrolytic capacitors in this set. The tuner is working and the sound is ok but it should be a lot stronger and a lot louder. I checked all the flexible resistors and the fixed resistors but maybe I missed something. The Schematic is on AK page 1-63 of Riders. The tubes test good too. Please help. I'll check all suggestions.
::
::Thanks,
::
::Dave
::
:Dave,
:
:I restored an AK model 20. I replaced the standard parts, checked tubes and powered the radio up. I received stations with low volume, when touching the long wire antenna i could make the volume go up.
:
:Eventually I found a break in the volume control, after I replaced it the volume worked properly.
:
:Mitch
:

:Mitch,
: That "volume" control is not right. However it's not the same as what we call a volume control today. (Will a carbon type work as a replacement?) It's doing something to the "control" tube, adjusting a voltage (the bias voltage). This control tube I'm assuming is an early AVC tube, but somewhat manually controlled by this "volume" control. That's kind of an interesting circuit. It's doing something to the cathode of the control tube and then the control tube, in turn, is doing something to the cathode of the second detector tube to adjust the bias and change the volume. Very interesting, but I'm not sure I totally understand how it works.
:
:Thanks,
:
:Dave
:::Hello All,
::: I replaced all the paper and electrolytic capacitors in this set. The tuner is working and the sound is ok but it should be a lot stronger and a lot louder. I checked all the flexible resistors and the fixed resistors but maybe I missed something. The Schematic is on AK page 1-63 of Riders. The tubes test good too. Please help. I'll check all suggestions.
:::
:::Thanks,
:::
:::Dave
:::
::Dave,
::
::I restored an AK model 20. I replaced the standard parts, checked tubes and powered the radio up. I received stations with low volume, when touching the long wire antenna i could make the volume go up.
::
::Eventually I found a break in the volume control, after I replaced it the volume worked properly.
::
::Mitch
::
:
:
Dave,

My "Volume" control was not like todays either. It was a mechanical type assembly, I disassembled it to understand it, visual was needed.

Looking at the schematic shows how it controls the antenna signal for volume through the circuits, almost the same as my old unit.

I replaced it with a new carbon type hidden into the mechanical assembly. As long as it is not a wire wound you will be ok.

Mitch

Hi

Volume control adjusts bias on a control tube. In turn this tube changes grid voltage on RF and IF tubes, controlling volume. This volume control is in the power supply divider and should be wire wound.

Schematic shows 550 ohm volume control in late models and .5 meg in early. .5 meg wouldn't be right in this circuit.

If max volume is at end of the control might try changing value of the series resistor (670 ohms) to ground.

Norm

::Mitch,
:: That "volume" control is not right. However it's not the same as what we call a volume control today. (Will a carbon type work as a replacement?) It's doing something to the "control" tube, adjusting a voltage (the bias voltage). This control tube I'm assuming is an early AVC tube, but somewhat manually controlled by this "volume" control. That's kind of an interesting circuit. It's doing something to the cathode of the control tube and then the control tube, in turn, is doing something to the cathode of the second detector tube to adjust the bias and change the volume. Very interesting, but I'm not sure I totally understand how it works.
::
::Thanks,
::
::Dave
::::Hello All,
:::: I replaced all the paper and electrolytic capacitors in this set. The tuner is working and the sound is ok but it should be a lot stronger and a lot louder. I checked all the flexible resistors and the fixed resistors but maybe I missed something. The Schematic is on AK page 1-63 of Riders. The tubes test good too. Please help. I'll check all suggestions.
::::
::::Thanks,
::::
::::Dave
::::
:::Dave,
:::
:::I restored an AK model 20. I replaced the standard parts, checked tubes and powered the radio up. I received stations with low volume, when touching the long wire antenna i could make the volume go up.
:::
:::Eventually I found a break in the volume control, after I replaced it the volume worked properly.
:::
:::Mitch
:::
::
::
:Dave,
:
:My "Volume" control was not like todays either. It was a mechanical type assembly, I disassembled it to understand it, visual was needed.
:
:Looking at the schematic shows how it controls the antenna signal for volume through the circuits, almost the same as my old unit.
:
:I replaced it with a new carbon type hidden into the mechanical assembly. As long as it is not a wire wound you will be ok.
:
:Mitch
:

:Hi
:
: Volume control adjusts bias on a control tube. In turn this tube changes grid voltage on RF and IF tubes, controlling volume. This volume control is in the power supply divider and should be wire wound.
:
: Schematic shows 550 ohm volume control in late models and .5 meg in early. .5 meg wouldn't be right in this circuit.
:
: If max volume is at end of the control might try changing value of the series resistor (670 ohms) to ground.
:
:Norm
:
:::Mitch,
::: That "volume" control is not right. However it's not the same as what we call a volume control today. (Will a carbon type work as a replacement?) It's doing something to the "control" tube, adjusting a voltage (the bias voltage). This control tube I'm assuming is an early AVC tube, but somewhat manually controlled by this "volume" control. That's kind of an interesting circuit. It's doing something to the cathode of the control tube and then the control tube, in turn, is doing something to the cathode of the second detector tube to adjust the bias and change the volume. Very interesting, but I'm not sure I totally understand how it works.
:::
:::Thanks,
:::
:::Dave
:::::Hello All,
::::: I replaced all the paper and electrolytic capacitors in this set. The tuner is working and the sound is ok but it should be a lot stronger and a lot louder. I checked all the flexible resistors and the fixed resistors but maybe I missed something. The Schematic is on AK page 1-63 of Riders. The tubes test good too. Please help. I'll check all suggestions.
:::::
:::::Thanks,
:::::
:::::Dave
:::::
::::Dave,
::::
::::I restored an AK model 20. I replaced the standard parts, checked tubes and powered the radio up. I received stations with low volume, when touching the long wire antenna i could make the volume go up.
::::
::::Eventually I found a break in the volume control, after I replaced it the volume worked properly.
::::
::::Mitch
::::
:::
:::
::Dave,
::
::My "Volume" control was not like todays either. It was a mechanical type assembly, I disassembled it to understand it, visual was needed.
::
::Looking at the schematic shows how it controls the antenna signal for volume through the circuits, almost the same as my old unit.
::
::I replaced it with a new carbon type hidden into the mechanical assembly. As long as it is not a wire wound you will be ok.
::
::Mitch
::
:
:
If wire wound rheostat look for break in the solid wire or loss of contact with wiper arm. Still think it would be a simple new type of pot with carbon.

Really not sure if the control is bad by the return post.

Mitch

Norm,
I found my mistake and the 47 is now biased on. The volume control has a problem. The sound is either very loud or all the way down to zero, no sound. There is no in between. Either full blast or nothing. There's a few spots where the volume is lower but once you let go of the control the sound fades to nothing. So I think the control has dead spots or it's broken at or near the low end. The sound is very good even when it's too loud. But it's too loud.

I'll check to see If I made any other mistakes and let you know what I find.

Thanks,

Dave
:Hi
:
: Volume control adjusts bias on a control tube. In turn this tube changes grid voltage on RF and IF tubes, controlling volume. This volume control is in the power supply divider and should be wire wound.
:
: Schematic shows 550 ohm volume control in late models and .5 meg in early. .5 meg wouldn't be right in this circuit.
:
: If max volume is at end of the control might try changing value of the series resistor (670 ohms) to ground.
:
:Norm
:
:::Mitch,
::: That "volume" control is not right. However it's not the same as what we call a volume control today. (Will a carbon type work as a replacement?) It's doing something to the "control" tube, adjusting a voltage (the bias voltage). This control tube I'm assuming is an early AVC tube, but somewhat manually controlled by this "volume" control. That's kind of an interesting circuit. It's doing something to the cathode of the control tube and then the control tube, in turn, is doing something to the cathode of the second detector tube to adjust the bias and change the volume. Very interesting, but I'm not sure I totally understand how it works.
:::
:::Thanks,
:::
:::Dave
:::::Hello All,
::::: I replaced all the paper and electrolytic capacitors in this set. The tuner is working and the sound is ok but it should be a lot stronger and a lot louder. I checked all the flexible resistors and the fixed resistors but maybe I missed something. The Schematic is on AK page 1-63 of Riders. The tubes test good too. Please help. I'll check all suggestions.
:::::
:::::Thanks,
:::::
:::::Dave
:::::
::::Dave,
::::
::::I restored an AK model 20. I replaced the standard parts, checked tubes and powered the radio up. I received stations with low volume, when touching the long wire antenna i could make the volume go up.
::::
::::Eventually I found a break in the volume control, after I replaced it the volume worked properly.
::::
::::Mitch
::::
:::
:::
::Dave,
::
::My "Volume" control was not like todays either. It was a mechanical type assembly, I disassembled it to understand it, visual was needed.
::
::Looking at the schematic shows how it controls the antenna signal for volume through the circuits, almost the same as my old unit.
::
::I replaced it with a new carbon type hidden into the mechanical assembly. As long as it is not a wire wound you will be ok.
::
::Mitch
::
:
: