Sunday, September 6, 2015

Experimental WSPR 30m setup

After 178 x 2 minute WSPR transmissions I have a result and can share the outcome of this experiment.
I have been transmitting with a homemade magnetic loop with a 92% efficiency installed inside the garage on the floor! Transmitter was the W5OLF WSPR VCXO-AXE 30m transmitter with 1W. This transmitter has been built last January. I always wanted to have a independent beacon transmitter which doesn't use the mains net and doesn't use my home base antennas. So I powered the transmitter with solar power. The result is amazing considering the setup. Best DX was ZL1RS with a distance of 17750km.

The magnetic loop has been made with 22mm copper tube which was left by the previous home owner. I found a nice "trombone" idea for the capacitor on the internet, it works very well. At first I contructed the pick up loop with copper wire and had not enough capacitance so I constructed a extra cap on top. PE1BVQ Hans suggested I really should use thick coax cable for pick up loop construction and it works very well. SWR on 10.140 is 1:1 and exactly 50 Ohm.
The transmitter finally at the place it was ment for. The only problem is I can activate it only 99 times a time slot of 2 minutes. After that I have to press a button again for another 99 times. I have programmed a 6 minute break for the experiment to get as many spots as possible. I'll probabely experiment with other time settings in the future.

I really didn't expect it would work this well with a antenna inside a building and on the floor.


Paul Stam PAØK said...

Hallo Bas, een mooi resultaat. 73 Paul PC4T

PE4BAS, Bas said...

Hallo Paul, zeker gezien de slechte condities....73, Bas

Unknown said...

Leuk resultaat Bas!
Ik heb zelf ook een TX only setup met magloop antenne.
Ik las dat je telkens maar 99 transmissies kunt doen omdat je systeem niet tijdgesynchroniseerd is. Ik heb dit zelf opgelost door mijn baken te synchroniseren met de duitse tijdseinzender DCF77. Zie mijn eerdere post voor verdere details.
73, Allard PE1NWL

PE4BAS, Bas said...

Hallo Allard, dat ziet er mooi uit. Van mij hoeft het niet zo ingewikkeld 99 transmissies is goed. Kan ik ook af en toe even kijken of alles goed gaat. Neemt niet weg dat dit een leuke oplossing is. 73, Bas