Saturday 16 September 2017

FT8 on Six Metres

Started the Sporadic E season this year using JT65A again, never had any idea that FT8 would be coming along.  Just happened across it somehow, really can't remember.  Downloaded WSJT-8 and joined in the fun.
FT8 really comes into it's own on Six where short lived openings would probably be missed with JT65.  FT8 apparently looses some sensitivity compared to JT65 but the great advantage of quick fire contacts more than makes up for that.  Auto sequencing helps to speed things along. Wasn't too sure about that at first but soon subscribed as the fifteen second over can leave you floundering unless you are very quick and I wasn't.
If I'm around the shack but not able to operate I often just leave things running to see what is about sometimes with surprising results mostly capturing random calls form the continent when otherwise the band is dead.

PET HATE: stations sending RR73

Here's a nicely flowing FT8 QSO on 50MHz

Nicely flowing FT8 QSO
For FT8 I'm using a homebrew Six & Four Metre transciever, HB9CV antenna and 100 Watts.

Thursday 17 August 2017

RF interference noise from garden solar lights

Below is a video of the RF noise generated by three strings of 20 LED solar garden lights located in a neighbours garden. Cheap Chinese imports. The noise is S9 on Two Metres and my antenna is 200 feet away.  The interference is strong enough to be heard no matter where I point my beam including at the Moon.  Of course there is no noise during daylight, one small mercy I suppose!  70MHz & 50MHz are also affected, not sure about HF as I'm not really active there but I'll check soon.



Search using "Simple solar circuits" should give results that may help explain why they generate so much interference.

Here is a screen shot of 50MHz, the peaks of noise are sharper than on 144MHz and drift downward in frequency.

The RF noise drifting across Six Metres
I've purchased some clamp on ferrite suppressors. I will speak to my neighbours and hope they will be willing to fit them but I'm not confident that even if they are fitted the noise will be suppressed to the extent that it's not detectable. Even very low level noise will be a problem with EME.

UPDATE; The noise is also on HF 

Small peaks of noise are detectable on HF but appear fairly static and so if outside of a band they may not a problem. I'll update with a screenshot soon.