[ARC5] CV-27/UPN Mystery Box

[Michael A. Bittner]

Last weekend, I reported on a mystery black box that followed me home from the TRW swap meet.
http://s1367.photobucket.com/user/kmmab/media/IMG_7984_zps5ded00f2.jpg.html
I received several suggestions, from list members, as to what its function was and how to check it out. Here are the results of preliminary testing:

Power Up:  Came up very nicely on the variac with no smoke, no dripping or exploding filter caps, or anything bad.  Nice stable operation at 115 VAC.

Test Setup: RF sig. gen. modulated with 400 Hz connected to ANTENNA connector, signal tracer and scope connected to RECEIVER connector.

With center switch in the HF position, whatever goes in the ANTENNA connector comes out on the RECEIVER connector, as expected.

With the center switch in either the LF LOCAL or LF Distant position, the output peaks with an input frequency of 90 kHz with sharp drop off at 85 kHz and 95 kHz.  The output frequency is 1.95 kHz with 90 kHz input.

With the switch in the LF DISTANT position, the output signal level is identical to the input signal level.  It simply up-converts with no amplification.  With the switch in the LF LOCAL position, the input signal is attenuated.

Their are very minor frequency variations (10s of Hz) in the signal peak at different positions of the ANTENNA MATCH switch.

Absolutely no output could be obtained with 100 kHz input.  I was hoping to connect it to my Austron 2021L-01 LORAN C loop antenna, but probably won't bother with the setup since the loop is peaked at 100 kHz and the CV-27 receives nothing at 100 kHz.

I will be bringing the CV-27 to MRCG tomorrow. 

Any comments on my preliminary test results most welcome from list members.  73, Mike-W6MAB