1 Sep 2011

Improved QRSS30 beacon on 137.769kHz

This afternoon I did some experimenting with some new 42mm 3C90 toroids and my 1kV WIMA polypropylene capacitors. I've managed to increase the RF output of my QRSS3/30 beacon by around 5-6dB so I've put this on beaconing over the evening and overnight period in the hope that someone will see the signal and send me some screen shots. ERP with this new beacon is around 150uW.  Previous tests with the beacon ERP at around 50uW showed that the signal could be detected in The Netherlands. Each dB gained should improve my chances of being seen ever further. The screenshot shows my signal as received 101km away by G3WCB - quite a good signal at the peak of fades.


Casey Bahr said...

*micro* Watts! Wow! What is your antenna?

Anonymous said...

I like the the ugly construction.
My method is to cut strips of vero board into small pads and glue it to the coper side of the PCB. I wonder what results you would get if you used a kite aerial out on the fens with a good grounding rod.


Anonymous said...

Not much L.F experimenting at the moment, started playing around with
four metres.Built your 4 metre converter circuit and starting soon on a 4 metre DSB transmitter.

Roger G3XBM said...

Casey - the antenna used is a vertical loop (32/0.2mm wire) in the back garden with an area of around 80sq m. The plan is to double the wire thickness to halve the losses and gain another 3dB in ERP (some time).

Tony - yes a large vertical Marconi would increase the ERP considerably. From home my space is very limited and the loop is probably a good solution when there are lots of trees around.