WSPR 30m / 200mW IO92 / M0IFA and antenna update

 My Al-705 loop antenna has the capability of one, two or three loops. I will make a series of tests of WSPR reception on 10MHz (30m) with these options, with a transmit power of 200mW. 

Comparison

Now I am making a careful comparison, it will take 3 weeks! I want to see if the number of loops on my antenna makes a difference. First here is five days with 3 coils.

10MHz 5 days, 3 coils

I each case I have decided not to connect the loop directly to the QRP-Labs 200mW transmitter, but to connect via an ATU. My MAT-125E  auto ATU needs a minimum of 1W TX to tune, and so I have switched to my ELAD FDM-DUO at the same frequency 10,140,200Hz, and output a tuning signal of around 1.3W. Then switch back to the QRP-Labs 200mW output. The FDM-DUO showed an SWR of  1.5:1 on tune (down from 2.6:1 without the ATU. I checked the tuning also with my NanoVNA to see the SWR minimum at the correct frequency.

10MHz 5days , 2 coils

There is practically no difference between 3 and 2 coils on the loop antenna. May be just a little lower S/N ratio and fewer spots. 

Seems there is little difference between ,3 2 or 1 coil. Here's the one coil data

10MHz 5days , 1 coil

But more interesting might be any correlation, as you might expect, between sun spot numbers and the results. For example, the last day of one coil above shows a very poor day for 10MHz propagation. And sure enough the SN was a low 31. 

A fast way to check the propagation is a new app from N0NBH called "Solar". This runs on the iPhone but also on the new MacBook Air M1. Here is todays info:

SUN

And if you want the latest picture of the sun click here