a 80m RX-mag loop

The following may give ideas to the WSPR'ers interested by 80m.

I built a RX loop - quick dirty job with plumber / electrical PVC - let say 2 hours work.
- The main loop is a single turn, made from 5mm diameter coax (only the shield is used). It is "diamond shape" 1m by side. It is tuned by a 358pF silver mica capacitor + a 5-60pF ceramic trimmer.
- The coupling loop is also "diamond shape" ; 25 cm by side inside the main loop.
- The SWR at resonnance, measured with the MFJ249B is 1.1
- the gain is some 10dB superior to my "half size" K9AY so let say some -15dBi - more than enough for 80m with a modern transceiver...
- the bandwidth is about 20kHz at -3dB
- The front to side directivity measured on the OK0EU beacon during the day is some 12dB (of course it is almost omni for high angle signals - and bidirectionnal for low angle signals)
- The receiving performance is about the same as the K9AY, SNR's are about 5dB better than my vertical, sometime more...

It is still in my garden for the tests, but the plan is to take it as far as possible from the power line... When turned for NW it provides a useful attenuation of the "C russian naval beacon" on 3.594.000
I designed it with MMANA... pretty accurate for the capacitor value and the SWR...

That's it... pretty good for the time/money investment !