[Elecraft] OT question about receiving loop antenna -- SOLVED

[Victor Rosenthal]

The problem was that the supply voltage was slightly high, causing
increased gain in the preamp which allowed it to break into oscillation.
A 10 ohm resistor fixed it.

Thanks to those that responded!

73,
Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
CWops no. 5
http://www.qsl.net/k2vco/

On 12/11/2020 16:16, Victor Rosenthal wrote:
> I have an RF Pro 1b receiving loop antenna which I use for diversity
reception on my K3. It used to be sold by Pixel Technologies, and now it
is handled by DX Engineering. If there is someone else who has this same
antenna, please contact me off list.

> My antenna seems to be producing a strong (-50 dBm) spurious signal
that starts around 7400 kHz and drifts down. It is frequency modulated
at the line frequency. I have replaced the preamp and I still have the
problem. I am pretty certain that it is not an external signal, but I
would like someone else to check theirs for the same issue as a sanity
check.