uBITX crushes 160M contest #digital

Don - KM4UDX

Shaun, if you were using your ubitx, then we had a ubitx to ubitx wspr moment!

Shaun Scannell

Been playing a bit with uBIT-x and Kenwood TS-590SG, mainly on 30metres.  With 4 watts from the uBIT-X or 5 watts from the TS-590SG, on WSPR, I get almost the same results.  I can be spotted in ZL, VK, USA, Brazil, KH6, VE7, W/K 6, but I rarely hear any of those.  The problem here is NOISE.  Currently, I have S5 / S6 noise levels on almost every band.  In Europe, urban area's where high antenna's are not possible, all we hear is noise.  Some is ADSL delivered broadband (I have FTTP, but many don't), but mainly Chinese switched mode wall wart PSU 's from phone chargers, AC sockets with built in USB power outlets, Plasma TV's, Internet routers, VoIP phone adapters etc.  I've noticed just today (1st December) as several neighbours are putting out outside Christmas lights, that the noise on 14 Mhz has crept up from about S2/3 to S4/5 tonight.  

The people hearing my 4 watts of WSPR are probably (certainly in some cases) in isolated locations where they don't have a huge noise issue.  My friend VK4BAP spots me regularly at around -6 to -22 on WSPR.  But I spot him 1 day in 10 that he hears me.  He is in a rural location.  Nearest neighbour more than 1Km away.

73 Shaun G3ZSU

_Dave_ AD0B



cool info and nice result. Ubitx should be as sensitive as most any rig, as long as your antenna isn't dreadfully tiny. It might be slightly less crunchproof than a mid priced commercial rig with its preamp off, even its phase noise is decent.

LPF I would evaluate your 160m antenna as set up for swr at 3.6 MHz. If it looks like an open circuit, and you have axicom or replacement replay board, or v5 or 6, maybe. I did make a few contacts like that, but now I built a low pass filter in a small altoids tin as I had the parts, male bnc connector on one end so its easy to use.

I wish folk still did conversational psk31. I think it was killed by folk's long brag files.

Time to use the ubitx on 15m as we have sunspots.

73 curt
Very close to fcc monitoring station !


Way to go Don!
I have made a couple FT8 contacts on 160m with my V6.

Mick VA3EPM 

Dean Souleles

Don -

On the Tx vs Rx conundrum there is a one word answer.



Don - KM4UDX

Can a uBITX operate successfully on 160M?  Oh my YES. Here is a demonstration where a humble V4, made with paper clips and duct tape, broke an obscure 160M PSK contest called the "160M Great Pumpkin PSK31 Sprint". (see https://www.podxs070.com/)

Note first place for our home team, the  Undaunted Unbeatable uBITXerS!

For folks who don't recognize PSK as a digital mode, and I'm talking to you FT8ers, well, you can read up here (https://en.wikipedia.org/wiki/PSK31).  PSK mode is wonderful if you want to chat more than log. Converse more than exchange signal reports. Learn more than a grid square. And generally interact. hahah. 

The quick studies will note that there were only three actual QRP contestants. Well, no matter I say. 1st is 1st.  And, if the uBITX had operated in the 25W category, it would have TIED for 1st.  Given my current lack of "metal" (see other posts), I can't get to 25W without a fire extinguisher as a radio accessory. So the rig operates at 5 watts all day long on 160m without a single blip or beep. 

No I don't use a LPF, but at a few watts, I hope the FCC doesn't put me in shackles for a few unplanned emissions...

This fun little contest got me thinking about how the uBITX @ 160M worked on WSPR.  Data says the on 160M the uBITX TX is great, but RX can stand some improvement.  That is typically the problem.  You can TX better than you can RX. And RXing is sort of important to hobby. hahah.

Here are two maps. Both for 160m, one map for TX (going everyplace there is to go) and the second more restrained map for RX. Funny thing, as a kid, I always had big goofy ears. Guess they just don't do HF that well. hahah.

So, interested in uBITX on 160M? Well, go for it.  LPF is advised, but possibly not required under all conditions.