Atwater Kent Model 37 Almost Finished, But...

[Winky Dink]

I want to thank everyone for the help they've given me on my previous projects. Now I have a radio that's so simple that even a caveman can restore it.

I've been working on and off with this Atwater Kent Model 37 for the past year. I'm finally approaching completion. Started with this non-working set:



Now I have this:




I have a couple of issues to resolve before it goes back in the cabinet. First is the rheostat volume control. The problem is that it actually works as described below:



As you turn the knob the resistance and the volume increase until you get to the end of the resistance element, and then BAM! it jumps to infinite resistance and absolute max volume (and then your wife comes running up the stairs saying, "What in the heck was that?").



Question 1: Is there some purpose to this design? I think it would be best to have a stop so it doesn't break contact.

The rheostat spec is 0-400 ohms, and it actually reads 0-480 ohms. I get plenty of volume from a strong signal, but I've experimented with resistance up to 1K ohms, and it's still is well short of the max volume.

Question 2: Is there any reason that I shouldn't operate the set at higher rheostat resistance?

Unless advised otherwise, I'm going to put a stop at the high end of the resistance so it can't go off the volume cliff, and then add a 200 ohm resistor at the low end to boost the total resistance for more volume (volume is very soft starting at 200 ohms).

The second issue is that I receive 580 to 790 KC very well, but that's the entire range of my tuning knob. I'll ask about that later if I can't resolve it myself.

Thanks again everyone. When the radio's done I have an Atwater Kent horn speaker to work on.

If interested, this is a link to my AK37 Picasa folder:

https://picasaweb.google.com/coldrb/...eat=directlink

- Winky