Pre WWII Signal Corps shortwave radio receiver

[Bob Hudson]

Picked up an old National NC-100A shortwave radio receiver at an estate sale this week. When I got it home I was pleased to find a US Army Signal Corps Stamp on the chassis and receiver.

 

This is the version made to Army specs: instead of the AM broadcast band it has 200kc to 400kc (it does partially cover the AM band from 1300 to 1600) in addition to shortwave bands.

 

National used a technology that reduced the emissions generated by the receiving circuits and the military thought that was important because it reduced interference to other electronics, plus it was feared the enemy might have technology that could detect low-level emissions from receivers.

 

This model - NC-100A - was introduced in 1938 and cost the equivalent of $2,310 in today's money. The orange stamp below is the Signal Corps stamp:

 

 

[Bob Hudson]

A website at http://www.radioblvd.com/NC100.htm covers these extensively. The have a lot of info about the Navy version, which was called the RAO:

 

[Bob Hudson]

I have to say I was surprised when I plugged this and it worked! It's over 70-years-old and components, especially capacitors, tend to go bad over the years. The radio works, but needs work.

 

Here's a video of it in action, so to speak:

 

 

Here's what these look like inside:

 

 

 

[Hue Miller]

The knobs are also National but from their 1950s civilian equipment. Finding original knobs will not be too difficult.

-Hue