SOTA QRP (one way) Can you beat this?

Last Friday evening on the 20m band I worked Jean Francois VE2VL as VA2VL/W2 on the summit of Giant Mountain (1410m) W2/GA-005 (10 points). Jean told me in an e-mail today that he was using 500 milliwatts on 14062 CW. He was 339 in locator IO94of at Pickering in North Yorkshire.

The distance was 5193.6 Km, so from Jean’s perspective he got 10.39 Km per milliwatt or 10387 Kilometres per watt.

Can anyone beat that for SOTA HF ODX in terms of Kms per watt? This claim is for one way QRP from a SOTA summit to a SOTA Chaser fixed station.


Phil G4OBK

In reply to G4OBK:

Excellent work Phil, impressive chasing!

Back on 15 Mar this year I gave a homebrewed (ugly style) rockmite 30 a go on the air. I only get 300mW out of this one, probably due to my chaotic building style or the low pass filter being a bit too low.

Well, I was lucky enough to be heard by Bill W4ZV early in the morning (for him) at 10:33Z from GM/ES-062. This one was on the 30m band, it knocked my socks off. Cheers again Bill! He gave a 449 for me, he got 559 back.

I’ll claim 6041km, 20136 km/watt.

Ian mm0gyx

In reply to MM0GYX:

On the first outing with my RockMite 20 I worked Jean, VE2JCW from G/CE-001.

I had roughly measured the power output when I built the rig, and it was “around” 400mW whilst using the bench PSU.

Whilst portable, I was running at a lower supply voltage so I can only guess at the Output power. It was probably about 300mW but that’s a pure guess.

G/CE-001 to VE2JCW is 5110Km.
@ 300mW = 17033 km/W
@ 400mW = 12775 km/W

I hope to improve on that during the Mighty Mite weekend!

I seem to remember Colin, M1BUU writing about his pretty remarkable achievement with a RM.


In reply to G4ISJ:

I seem to remember Colin, M1BUU writing about his pretty remarkable
achievement with a RM.

Yes. Pete, I was running a RockMite 20 from a tired 9v battery back in August 2012. After my first round of CQs, Barry, N1EU responded after seeing the auto spot. Barry had no idea I was QRPp at the time. I emailed him afterwards and he was pretty surprised!

I measured the rigs output at work the next day using the same battery, the power was 89mW. Whilst I didn’t measure the power at the time of the QSO, I’m confident that my later measurement was pretty close to what it would have been at the summit.

My certificate from QRP ARCI records the QSO at 39,393 miles per watt.

I’ve also worked Bill W4ZV on 30m with a RockMite at around 400mW.

Colin M1BUU


Using a locator square distance calculator, I work out the distance at 5218.4 km. Equivalent to 58.6km per mW or 58,633.7 km per watt.

In reply to M1BUU:

Hi Colin,

Do I need to be a member of QRP ARCI to be able to claim a QRP 1000miles per Watt certificate ?


Robert G0PEB

In reply to G4OBK:

I was heard in California while running less than 100mW on a SOTA activation.

73 Richard G3CWI

In reply to G0PEB:

Do I need to be a member of QRP ARCI to be able to claim a QRP
1000miles per Watt certificate ?

I’m not 100% sure if you have to be a member. At the moment the web page is going through a (slow) transistion phase, it’s not been fully operation for months. QRP ARCI keep promising that the site will soon be up to full speed.

I like to be a member of QRP ARCI, the mag QRP Quarterly is very good, it works out at £4.50 an issue considering the £18 a year subscription. Recommended.

The web page is here -


Blimey these fantastic results puts m Chaser QSO QRP distance per watt into the shade!

Well done one and all…

Phil G4OBK

In reply to G4OBK:

I think your qso result is remarkable, in cases like that I think the chaser is the one doing the work. It’s easy enough to sit calling cq sota. Must take patience to get that weak signal in to the phones, not every op has that patience I think Phil (-:

Ian, mm0gyx

In reply to MM0GYX:

Its true that not every operator is prepared to winkle weak stations out of the noise, whether it is SOTA or DX, but it is a skill that is a pleasure to acquire and use and in my opinion is an important part of the skill-set of a successful ham. Such QSOs are a team effort, the QRP station maximising the efficiency of his rig and antenna, the chaser getting every last ounce of reception performance out of his station and ears. I would congratulate both parties equally.


Brian G8ADD

In reply to G4OBK:

Nonsense Phil, you’re not into the shade, it’s enthuiastic hams like yourself that enable all these wonderful achievements to take place. I think it’s probably a lack of QRPp DX stations to chase that makes the difference here - come on NA ops, get those RM’s fired up for G3CWI’s Mighty Mite weekend from their home continent!

In reply to MM0GYX:

I agree Ian, I think the most of the hard work is done by the chaser. I am very thankful to the chasers with good ears to allow me to have my fun with my toys!

In reply to G8ADD:

Brian, I apprceciate your angle, but I would still say that the listening station is the one whose achievement should be most honoured. I agree that having a QRPp QSO is a two party thing and both parties have to do the right thing for a QSO to take place. No doubt about it that there is skill involved in making contacts with minimalist radios and low power.

I found this article a couple of years ago - I found it very interesting reading.

Keep an eye out for the next episode of Ham Nation, there might be a video about QRPp SOTA operating :wink: Ham Nation | Excitement & Importance of Ham Radio | TWiT

72, Colin

In reply to G0PEB:
NAQCC is free and offers a 1000 mpw award certificate.


In reply to WH6LE:

I’d like to make some claims here, dubious and hard to prove but I was impressed.

I worked Ken GM0AXY today on 12m CW from GM/SS-172, a direct path of 45km. But Ken had many round the world echoes and I was working the 5th set! That gives me

4x earthrad + LP distance / power

(4x 40041 + 39996) / 4.5 = 44480 km / watt.

Just about every station I worked in NA was audible long path and short path. Some had multiple echoes too. The CW was very hard to copy.

I worked Mickey 2E0YYY S2S on TW-004 on 12m SSB. That’s 44432 km/W. Mickey had 5 clear round the world echoes, I counted them many times.

Most definitely hard work to copy multi-echo CW but oh so much fun.


In reply to MM0FMF:


Hard to prove? Definitely!

Haven’t checked the Maths, but sound RF theory though :slight_smile:

I have probably experienced my own round the world echoes before, but having only recently started using full break in on CW (I used to use 200ms delay, enough for a break between each letter at 24WPM), as full break in does take a bit of getting used to for the un-initiated. Surely those relays clattering away can’t be doing them any good!

I was probably never fast enough dropping the PTT on SSB to notice before. In any case I was very pleased to hear my own CW transmission arriving back here in Blackburn after a very long trip. That could possibly explain why I was also hearing other G chasers as strong as I was that day, maybe not direct, but possibly all the way round?

I heard Klaus DF2GN/P mention that CW on 12m was a little difficult on one activation due to the echoes, & with other un-feasable QSO’s also taking place that day, I think it is safe to say that conditions on the high HF bands were pretty good :slight_smile:

The expression “work the world on a wet piece of string” comes from conditions like this, or maybe just a little bit better, for those who can remember :slight_smile:

Good fun?

Most definitely yes!

Thanks & 73,

Mark G0VOF

In reply to G0VOF:

In reply to MM0FMF:


Hard to prove? Definitely!

Not really. The total path length round the world gives rise to a delay of about 138.5mS so by measuring the delay it’s easy to surmise how far the signals have travelled. And if they did not go round the world where did they go that gives rise to exactly the same calculated delay? Occam’s razor.

73 Richard G3CWI

When Andy says “earthrad”, does he not mean “earthcirc” or “6.28earthrad”?


In reply to M1EYP:

Yes! I remember typing “earth radius” into Mr. Google to get the value and doing the 2*pi calculation. I’ve typed that rather than circumference. The figure I used was a simple average of the 2 often quoted values for the radius because as we all know, the Earth is a geoid not a sphere.


In reply to MM0FMF:

It has recently been noted that the volume of a pizza of radius Z and thickness A is


Now that’s a fact.

73 Richard G3CWI