[Milsurplus] MN-20E Loop questions

[J. Forster]

>From TM 8-10-256 dated 23 December 1943, only pins 1,3, and 5 are used. Pin 3 is grounded and as I remember
the loop has a center tap connected to pin 3, so you want to use a differential amp across pins 1 and 5. In
the MN-26 there is an RF transformer  primary connected across 1 and 5 and 3 goes to chassis and cable shield.
The transformer gives a high CMRR. The grounded CT of the loop limits the common mode signal.

There is no reason at all to tamper with the loop, IMO.

-John


Michael St. Angelo wrote:

> I had some spare time on a rainy Saturday afternoon and went through some surplus.
> I found a MN-20E loop antenna and MN-52H controller I bought from G&G radio in 1982.
> (The recipt was still in the box). I intended to construct a VLF loop preamplifer with this loop
> but things like marriage, career, etc. got in the way. [snip]