There is a crystal socket to the side.  There are also snap fasteners on the cover for the battery connection.



I'm thanking it might have been some sort of test rig.  Say, to be carried out on the flight line to adjust some avionic thing.

AL

On 11/29/2025 8:50 PM, [email protected] wrote:
I don't see any XTALs and the selector switch has torroids 
The 3B4 tube was first introduced in 1948 according to the release notice, so it was post WWII.

The more I look at it, the less it looks like a radio. maybe a metal detector chassis?
On Saturday, November 29, 2025 at 03:28:43 PM EST, Al Klase <[email protected]> wrote:




  

Larger tube is a 3B4 (Gone to air)

What is this?
AL
--
ARK Sig Block Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/


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--
ARK Sig Block Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/