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The Magic of Radio

I recently swapped to part time working to enable me to look after my 2yr son for part of the week. As my wife works school term time only, today I had a bit of free time. The Easter holidays started yesterday afternoon for me and tomorrow we start our journey towards the Isle of Mull for our 2015 family holiday.z

All my usual radio gear is packed up ready to go on holiday, so when the chance for a sneaky SOTA activation presented itself this afternoon, I had to dig deep to find some radio gear! My home brew SSB rig was staring at me, so I packed that, along with a home brew microphone and home brew 20m dipole which still needs finishing off to be honest! For CW, I found my SW-20+ in the ‘radio cupboard’ along with a Czech straight key purchased at Blackpool rally some time ago from Mike G0CVZ.

I chose to activate Rombalds Moor as it’s my nearest summit. The weather was great, hardly any wind and glorious sunshine with fantastic visibility. I easily qualified the summit on home brew SSB, it was such a buzz, it’s the first time I’ve run the home brew rig with home brew antenna!

I then powered up the SW-20+, something I’ve not done for quite some time! I wasn’t sure if the KU6J spotter would spot me as I hadn’t entered an alert, so I fired up SOTAwatch on my phone. I saw a spot for John signing as CT9/M1NNN/P from CT3/MI-001 on 20m CW - I hadn’t expected John to be active on 20m. I’ve been looking at the alerts for possible chasing whilst on holiday and had noted John’s trip, along with M1EYP’s later in the week. I just knew I had to try to work John!

As luck would have it, John’s signal steadily grew in strength whilst I was listening and my VFO seemed to be reasonably stable enough to allow listening for quite a while. I called John a few times and I was thrilled to eventually make it for an S2S, both parties receiving 559 reports. I was very pleased with my 1 watt chase!

I then called CQ and worked a few stations, including a nice S2S with F6HBI/P on F/AM-473.

After the activation, I felt really good, a great start to my holiday! What more can an activator ask for - perfect weather, summit to summit contacts, all home brew QSO’s.

I’m hoping to make it on to a SOTA summit on Mull, but I don’t know for sure yet. I’ve packed my 20m/30m MTR and dipole, and also my FT817 for chasing from the holiday cottage (anyone for WAB?).

Thanks for the contacts today!

73, Colin M1BUU


Hi Colin,

I’m pleased you had a good day, the weather was much better here in Blackburn than it has been all week,sunny & much less windy!

Home-brewing is one aspect of amateur radio that I have missed out on, as my short career in an electronics workshop came to an end just as I was doing something about my lifelong fascination with radio. I am always impressed with your HB radio’s, much neater than any of mine would be & they work very well too :smile:

Best of luck on Mull, you may find 30m a little poor for inter-UK as the f2 critical frequency hasn’t risen much above 7MHz for the past week or so. 30m/20m should still be fine for EU and beyond & there may be the odd bit of surprise short skip f2. There may even be some enhancement on 30 & 20 as we enter the spring sporadic E season. Of course, eS is more beneficial on the higher HF & VHF bands, but lower bands can also be affected to some degree.

In any case, have a great trip & thanks for the nice report.

Thanks & best 73,

Mark G0VOF

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Hello Colin, it is always a pleasure to get a S2S Qso.
I enjoyed our s2s today.
About the magic of Radio: today on summit i was CQing sota on 24mhz
with my Ft817 5 watts into an inverted V dipole and i got a japaneese pile up.
4 JA, gave me strong solid report.
Just Magic!
73 from Gerald

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Thanks for the information Mark. Propagation is not something that I found out much about. I use 30m and 20m because they’re convenient! A 20m dipole is a nice size and its easy to get it high up in terms of wavelength. I like 30m because it’s almost like a reward for being able to do CW! Of late the pile ups on 30m has put me off a bit; after 10-15 minutes at 20wpm, my brain is fried!

I do get a kick out of home made gear, it is a very satisfying thing to make contacts on something you’ve built yourself. I’m not great with words but every time I get good contacts with QRP, I find it truly amazing. I’ll never grow tired of working our friends across the world with low power. How does a 6w radio and a length of 7 strand equipment wire throw a signal across 15,000 miles? Regardless of technical explanation, I regard it as magic!

I will have 40,30,20,17,15,12,2 and 70cms with me on Mull, but I’ll only have 20m/30cm CW for SOTA.


For a long time I felt I was being cheeky using 30m because my CW was so ropey.

Split operation Colin. The MTR does split as does the 817.

I should make an effort to get on the higher bands. I have a dipole for 12m, I ought to give it a try.

I have never worked in to Japan, that certainly would be nice!

Sorry for bad sending, I haven’t used a straight key for years! Was fun though!

73, Colin

MTR doesn’t really do split, you can shift the RIT up to a Max of 1.5kHz as a bit of a dodge.

Do you really expect me to cart an FT817 up a hill?!!

Arf! Just set the RIT to +1kHz and send UP1 after every CQ. I wont tell anyone you are using RIT not twin VFOS.


I have worked you on CW more than once, there is absolutely nothing wrong with your sending!

Take whatever radio you want up the hill, if chasers want to work you, they will do it your way :wink:

Thanks & 73,

Mark G0VOF

Thanks Mark! I usually use a Palm Mini paddle or Palm Pico paddle, both these keys are currently packed up with the rest of my holiday kit. Yesterday I had to use a straight key as I don’t own a third paddle (I lust after a Kent twin, but not for SOTA!).

My speed has increased somewhat since the last time I used a straight key, I was doing on the job training yesterday!

73, Colin

Operating Split will probably not make Colin happy(er) because this simply shifts the pileup.
Split is well beloved by the chasers because it offers a clean(er) RX frequency and speeds up the QSO rate.
So take your time and have fun.

I am still a rookie when it comes to best practice CW operating, and have never tried to work split, though I have listened to a few operators using it.

One potential advantage is that calling stations spread out a bit, which makes it easier to pick out a callsign than if they are all calling on the same frequency. Obviously that occupies more of the band, though. So, is “spreading out” thought to be good or bad, or is it just down to preference?
For myself as a chaser, I tend to wait until everyone else has been worked before calling - but if everyone did that it would be a very slow process :o)

(I agree about the magic, Colin, and the first qso from a home brew rig is hard to beat!)



usually spreading is to let the dx (or in this case, the activator) decipher callsigns because the signals are not on the same frequency. Split is intended to get the callers off the dx frequency. Together they make it possible for the dx to tune through the wall of callers and pick out callsigns more readily. I used split quite frequently on 20m cw when in v85 land. it helps you work through the callers more quickly. There are some strategies for being heard more readily by the dx, one is to work out which way the dx is tuning through the wall of callers, up or down. Then position your tx so you are the next signal found by someone who is using a very narrow filter, usually 250hz or less. Another is to call slightly away from the main body of callers, so that the dx/activator using a wider bandwidth will hear your distinctive offset and be attracted away from the wall. Your mileage will definitely vary. Have to try a few things to see what works each time. QRP makes it even more challenging, but also more rewarding.
Good luck… have fun…
vk1da/2uh ex v85da

The magic of radio was again evident this morning on 20m when I was copying loud and clear several VK stations working Mike 2W0YYY/P from SOTA but I was unable to copy Mike in Wales, except for a couple instants when he was barely audible with a 31, I called him, but he didn’t copy me.
Best 73 de Guru.

Every so often I get the urge to do something different, on Saturday, I thought it would be fun to try 17m and 15m. Reports of poor conditions on HF had been floating about, but I thought I’d give it a try anyway.

The wind on Great Whernside was pretty fierce, so I had the apex of the SOTAbeams old prototype multiband dipole antenna at about 3m above the ground. Conditions on 17m seemed strange, I heard very little activity from EU but I was amazed when I was called by K1JD in Santa Fe, New Mexico with a very strong signal.

Activity on 17m soon dried up so I switched to 15m. Signals from USA were even stronger! I was thrilled to work KX0R in Colorado, an all time new state for me. The signal from KT5X in Santa Fe, NM (>4500 miles) blew me away! -

This radio thing is magic!

Colin M1BUU

My appetite for radio related activities has recently returned after a summer doing other activities.

I attended the RSGB Convention on the 14th/15th October in Milton Keynes and had an opportunity to operate the special event station GB3HQ, put on by the Camb-Hams using their mobile shack “Flossie”. I managed OK on 40m CW, but I did find it more difficult than I expected. At least the GB3HQ log book was a little bit fuller!

My appetite for CW QSO’s had been whetted so I when an opportunity to activate my local summit G/NP-028 presented itself on Friday 20th October I took it! I used my home built KD1JV MTR-5B and matching home built 5 band linked dipole. I started off on 21MHz but I had no takers, although the RBN had picked me up. I moved down each band but finished on 10MHz as the croc clip on one of the 7MHz links had broken off. :cry: My 5 band dipole has had a fair bit of use, since my veteran 3 band SOTAbeams dipole had been out of service with a broken wire (now fixed). I had a great time, I was very happy to work SV1RHL and VE2JCW, I don’t often work Greek stations and I certainly didn’t expect to be working across to Canada!

I have a little bit of time between the end of work and picking my son up from school each week day, so I decided that I would squeeze in another activation of G/NP-028 yesterday on the way home from work. I had replaced the missing croc clip on my antenna, so I thought I would start on 40m to offer G/NP-028 to those who might have missed out two weeks earlier. I was on air just 3 minutes after my alerted time, using my original 2 band Mountain Topper, which I built back in 2012. My Mountain Topper has never missed a beat, it has been extremely reliable.

First in the log on 40m was EA2DT, which took me by surprise as I’m used to working EA on 10MHz and above during daylight. Next in the log was Juerg, HB9BIN/P on HB/BE-101 for a nice S2S. I wasn’t ready for the wall of noise that then appeared as lots of callers called in! A notable QSO was one with Allan GW4VPX, I was pleased to get him in the log as I know he’s been working hard to get going with CW for SOTA. It was me who made the mistakes during our QSO, I struggled to send Allan’s name - sorry Allan! I was pleased to get four further S2S QSO’s in the log thanks to HB9BCB/P, DL/HB9CLT/P, DL4TO/P and DL/HB9AGO/P.

I needed to pack up at 1420utc at the latest and I’d worked all callers on 40m by 1408utc. I debated whether to give 20m a try, and eventually decided that I would. First in the log at 1412 on 14Mhz was SP9AMH, I was then called by Bob, AC1Z. I hadn’t even considered working across the pond and at first I thought I was being called by an eager EA station! I was confused for a little while - my brain was convinced that I was listening for a Spanish station, eventually I managed to re-set and work Bob without further issue. In all, I worked 7 stations on 20m, including VE1WT, VE2JCW and N1GB. The signal from N1GB was huge and George gave me a 579 report. I sent “Wow” in my excitement! In all I had 38 QSOs across both bands in just under 50 minutes.

Despite the doom and gloom regarding sun activity, there are still QSO’s to be made and working ‘across the pond’ with a mint tin will always feel like magic to me!

I have taken up radio construction again, at the moment I’m building a KD1JV Designs Soda Pop. Soda Pop is a play on words around ‘SOTA Op’. The Soda Pop is a single band CW transceiver using Arduino for control and an SI5351A for frequency generation. 95 kits were offered back in March. Due to a mistake in ordering, a spare PCB containing several errors was included with each full kit. The spare PCB was intended to be used as a drinks coaster! It is possible to correct the mistakes on the spare board, so as I like a challenge, I decided to build the spare board into a 40m transceiver! The board is now up and running, I’ve already had some test QSO’s using it. I have made a custom case from aluminium sheet in my usual style.

73, Colin


The magic of radio still sparkles for me!

I love my little QRPp rigs but in recent years I have found myself using them less and less. I have been running my MTR-5B flat out from a 3S lipo, getting a out 4 watts output. Reports have been mostly poor, like 339, 449, 559 etc. I’ve always managed to qualify each summit but the QSO numbers have been down.

I saw the 50w QCX amplifier on the QRP Labs website and thought it would be perfect for SOTA. The amp is efficient because it is not linear and runs class C. As I’m a CW op, the amp is perfect for me. The fun SOTA events seem to mostly happen on 20m, so I thought having some decent power on that band would be great. The QCX amp needs a PTT signal from the driving radio to switch between RX and TX. I’d built a QCX-30 a couple of years ago but I haven’t really used it.

I hatched a plan to swap my QCX-30 over to 20m, install all of the needed mods and update the firmware. The firmware updates add some subtle differences to certain routines that otherwise might cause an issue when running the amp. I picked off the PTT signal from the QCX pcb and plumbed it to a 3.5mm stereo socket so that I could use a cheap 3.5mm audio auxiliary cable to connect the rig to the amp.

The QCX amp works across all of HF but has a single low pass filter, so this limits the choice of band to one or at a push two bands (depending upon harmonic relationship). I obviously used the 20m LPF option for my amp. The amp went together well and worked first time. The toroid windings were a bit fiddly but with care and patience it was do-able.

The EU-NA SOTA QSO party was coming up and I thought it would be a great opportunity to try the new amp. I’d built the amp and it had sat on my shack shelf for a while, however the QCX was still without a proper enclosure. I had bought all the bits and an extruded case earlier in the summer.

Thankfully I got the QCX boxed up in time for the EU-NA event but I hadn’t had time to give it a test run. I had never tried the rig since swapping it over to 20m.

I ordered some 5S lipo batteries at a discount price, they are 3000mAh, so I wasn’t sure if they’d last long. The quoted current draw for the QCX amp is 5 to 6 amps. I was thinking an hour of use would be somewhere in the expected ball park, I was wrong!

I made 97 QSOs with the QCX and amp during the Transatlantic SOTA event, I ran solidly for 2 hours and I was still on the first battery! My charger reckoned that the 5S lipo was 79% depleted when I plugged the battery in for a storage charge at home.

22 of my QSOs were transatlantic and my signal reports were all much better than normal. The increase of solar activity also helped a lot without a doubt.

Of course, running higher power is bound to make QSOs a bit easier, but for me, I found pleasure in the fact that I had put together the system. Boasting is not my aim, but I just find it amazing that I was able to build and modify a radio and an amplifier, furnish the necessary cabling and make so many fabulous QSOs using an antenna I’d made myself.

Flashing the QCX with v1.05 firmware using Arduino Uno.

The QCX amp kit

A few toroids to wind

Final stage, adding the PA transistors.

Starting with the QCX case.

Extruded enclosure purchased from a Hong Kong based seller via Ebay- £8.14 delivered.

Getting there.

Brother labelling machine put to work (I love my labelling machine!)

G/NP-009, A successful test run for the QCX and QCX amplifier.


Nice report, I was on Buckden Pike last summer before heading to Iceland. I can’t wait for the QCX Mini to come out. Really gutted about the curfew; I can’t sleep out and do a night time activation with my QCX 80.
73 de OE6FEG

I think the QCX mini has potential to out sell the other versions. The MTR has probably been discontinued although a 4 band version with built in SWR meter is supposedly going to appear. There aren’t many choices for small trail friendly CW radios these days. My last shipment from QRP Labs cost $12 to ship and arrived in about 3 days. So as a rough guess, $55 for the QCX mini kit, $15 to $20 for nice case and $12 shipping = ~$87 or around £66.

£66 for a smart CW transceiver seems like an absolute bargain!)

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I’m beginning to regret not upgrading my MTR3b to the LCD version. Someone told me the receiver is also better, although I take these things with a pinch of salt. I also heard they have not yet decided if they will do another run next year; again, I have no idea if that is true or not. Well, for multiday trekking its lightweight made an acceptable trade off for the very simple interface and zero SWR protection. I always loved mine. In contrast, the QCX has an awesome receiver and you get the pleasure of making it yourself. Like you, I think the QCX Mini is going to sell like hot cakes. It looks great, there’s less work involved (and thus less need for signal tracing post construction) and the price is rock bottom.
73 Matt

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