DM/TH-064: 144 MHz Meteorscatter

During the 2019 Perseids maximum I managed to complete a random MS QSO on 144 MHz. On the 13th August at 1139z final rogers were received from YU7ON in KN04ax. Mode was FSK441. My set up was 50 W from an FT-857 into 2x5 elements DK7ZB 5 m above ground level. I used my contest callsign DP9X.

YU7ON peaked exceptionally strong at 48 (burst > 20 s at S 6/7). However, at the time I started sending the report he was ‘only’ 37 and so I didn’t change the numbers during the QSO. The time zone on my tablet was Dakar. Must have messed up the hours while synchronising the computer with the GPS time.

The QSO was rather tough or let’s say boring work. I was QRV on the summit from 0730z and so it took four hours for the first QSO to come to the log. In the morning I however decoded a bunch of strong G, F, and HB9 stations via tropo, but wasn’t very keen to call them. We all wanted to make MS contacts, not tropo, didn’t we? Later on, good bursts from LZ, YO, EA5, and I were heard, but no QSO made.

This was the third attempt to complete a SOTA MS QSO: First try in 2017, when all DM/NS region was overcast during the Perseids maximum, but my YL insisted in having clear skies if I wanted her to join me that night. Of course I did! So we had to go north where the sky was clearer in order to watch the Perseids and make a MS contact, but there is no SOTA reference up the North. In August 2018 on the day before the Perseids maximum, I stepped into a thistle while deploying my station to check if everything’s working. The invisible thorn that could not be removed from my foot caused a proper inflammation and so I had to cancel the planned activation the next day.
Next aim is to qualify a summit on MS.


Good effort Pom,
I have not had chance for 2m MS for some years, since moving and loosing my 4x17 array at home plus the 8877!
6M is quite good with the modern digital modes, but antennas so much bigger.
I like the idea of the QRP MS challenge though.
73 Tim


Yes, I’d certainly be up for that as well.

It is quite a few years since I have run any MS, indeed the CW keyer and tape recorder are now museum pieces. I used to run a Trio TR-7010 into a QQVO6/40A giving 70W out and my antenna was a single 10 element. I made many contacts, both via skeds and random during the 1980’s using CW and SSB with this set up. The station was also sufficient for weekly skeds between myself and Giuliano I3LGP which we held at 06:00z on Sundays for many years. Usually we were complete inside 20 minutes running 2.5 minute periods. Bear in mind we are talking CW here… none of this “in the noise” stuff. Unfortunately we both moved house at the same time in 1993 which put paid to this arrangement. I then lost interest when computer generated modes came about, but recently I have been thinking of getting into MS once again.

Seeing you running the 857 Pom has given me an idea as I already have an interface to the rig and can run datamodes. For me it would be far more interesting to try MS than to run FT8, PSK31, etc on HF. The first thing for me is to get reasonably proficient with the software from home, so perhaps this is something I need to get on with. I would be happy to sit out for several hours on a summit to try to make some contacts, but as to whether anyone is willing to go out in the Geminids or Quadrantids… who knows?

73, Gerald


For me it would be far more interesting to try MS than to run FT8, PSK31, etc on HF. The first thing for me is to get reasonably proficient with the software from home […]

Hej Gerald,

in my opinion, MS using FSK441 is very different to the “in the noise” modes in regard to operating skills: Mostly you hear the signals the computer decodes and sometimes it is important to hear a ping or burst to manually start decoding instantly before the period is over in order to choose the appropriate answer for your next TX period. It is also important to have a look at what the computer decoded to get certain strings to another and put them together in your head. A good example is YU7ON’s cq. I heard a ping in which the computer decoded the call sign and “CQ” correctly, but QSY was rubbish. The second-next period I got call sign fragments and a clear “CQ 385” and QSY’d. He took another station first then, but when he returned to 370 to cq, I was able to answer instantly on the given frequency. This may save you good time to complete a QSO.

I use MSHV by LZ2HV on Win8. The software handles plenty of digital modes and they say, it decodes down to a lower SN level than WSJT. It is even operational with a ‘barefoot’ tablet computer. I broke the tablet’s keyboard the other day and had to use the touch screen features incl. the onscreen keypad. Anyway, I bet there are still some high-speed CWists on the band. :wink:

anyone is willing to go out in the Geminids or Quadrantids… who knows?

Here! fingersnip
During the 2017 Geminids I made four QSOs using my SOTA setup. But since it was a typical winter in the Northern Plains with winds, rain showers and temperatures slightly above freezing, I chose the rather comfortable VW Caddy as a shack and a QTH in the city instead of a blank summit.
To put it in short words: weather depending I’m gonna be out then.


Just’ve looked up the coming Geminids in the IMO calendar:

Shower details -
[Radiant]: 07:28 +32.2° -
[ZHR]): 150 -
Velocity: 22 miles/sec (medium - 35km/sec) -
Parent Object: 3200 Phaethon (asteroid)
Next Peak - The Geminids will next peak on the Dec 13-14, 2019 night. On this night, the moon will be 96.31% full.

Except it’s gonna be in Mid-December, looks ideal: ZHR 150 and Friday night and/or early Saturday morning with a full moon.


Could be interesting and a good excuse to turn on the diesel heater in the campervan (Not SOTA obviously).
WX depending, I will give it a go - sked to follow nearer the time :slight_smile:

Well Pom, many thanks for all the information. Most useful and it will help me get back up to speed. I think I need to run MS on the 857 in the shack or maybe in the car before venturing out onto a summit.

It certainly seems like I have let the computer generated modes put me off MS, whereas I should have stuck at it. I currently have 150 watts available as the 6/40 was replaced by a BNOS linear. Soon I hope to have my 9 element back in service as well. As for the showers, my favourite is the Quadrantids which is usually quite short and intense.

It looks like I have something to work towards and an MS S2S looks like an admirable challenge.

73, Gerald

Great job!

Can you tell us how much Mah it took from the battery to complete the random contact?


After four hours of listening and some TXing, I had to change batteries during the QSO. Both are 6600 mAh LiFePos. So it must have been a vague 6000 mAh up to that point.
The needed capacity to make a contact can’t be predicted. More is better as it gives more operation time, thus a higher probability to complete one or more QSOs. Keep also the computer’s battery in mind. When it’s flat you will also have to quit MS operations, regardless of the TRX batteries.


As for the showers, my favourite is the Quadrantids which is usually quite short and intense. […]
It looks like I have something to work towards and an MS S2S looks like an admirable challenge.

Are we commited now, Gerald?
However I must admit that to my mind the Geminids with their broad maximum are a better fit for SOTA operations. Anyway, fancy any portable 2 portable QSO on the Geminids or Quandrantids maximae?

For an s2s I’d rather prefer the 2020 Perseids due to the expected time it might take to complete a QSO and the weather. :sunrise_over_mountains:


PS: The annual MakeMoreMiles Dubus MS Sprint Contest held during the Perseids has a QRP section (< 1500W ERP). Great for SOTA stations.

First I think I need to get into practice with the software Pom. My plan is to use the autumn to do this as this will be a period of inactivity on the summits front as my XYL is having a foot operation and I will need to spend more time around the home QTH.

I should be okay for portable later on in the year, but the weather will determine the nature of that. Operating portable from a vehicle is one thing, taking equipment up a summit is entirely another. As you say, the Perseids next year offers the best opportunity for an MS S2S, but there are showers earlier in the summer which might offer opportunities - some thought required. :grinning:

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Hi Pom
Done a bit of work on my 2m portable station this weekend.
I have downloaded WSJT 2.0.1 onto my sota win tablet (Surface Go), the mode options i have are

I have used FT8 on HF, and JT65 several years ago.
Question is - Should I use and learn MSK144 as the preferred mode for 2m MS? If not, what is the go to mode please?



Hej Tim,

MSK144 is the state of the art MS mode. It’s quite new and has some advantages over FSK441, which was the first MS machine generated mode.
Howver, I use FSK441 as for some reason I couldn’t get MSK144 running.

There are still plenty stations that use FSK441. I found it easy to use in the field as it tolerates more than 300Hz off frequency and even some drift easily. The software I use is MSHV.


Thanks for the info Pom
I will download it and have a go on my next leave.

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I wasn’t out during the Geminids maximum as the weather wasn’t very appealing. Instead, I deployed my SOTA setup at a radio friend’s garden hut. We heard plenty activity in MSK but not a single FSK signal.

Same during the Quadrantids. Only one FSK QSO spotted on the dx cluster and lots of good MSK bursts were decoded at home with the stationary setup and its cripled antenna, FSK again none. Seems MSK144 has taken over very quickly. Trying SOTA MS QSOs in FSK in the 2020 Perseids could end up in a private party. :wink:

This means, my recommendation to use FSK441 because it is robust and proven to work for a rucksack station on a summit is outdated. The state of the art mode MSK144 is supported by MSHV or WSJT-X. OPs who already successfully run a MGM SOTA setup with a software capable of MSK144 only have to get familiar with the only slightly different procedures. Testing the new mode is recommended anyway, see my example.

My SOTA setup has worked fine in FSK, though still no MSK burst was decoded successfully. The Quadrantids were a good opportunity to do some faultfinding. After connecting different radios to several computers, it seems the cheapo USB soundcard is the faulty bit. Good enough for FSK but failed with MSK. So I will get me another one and give it a try.


Hi Pom,

Many thanks for the update. I didn’t manage to get on for the Geminids and was away during the Quadrantids, though i was on a hill activating on the morning of 4th January. Although I haven’t tried MSK with my set up, I think that it will require an update of the hardware. It seems to be very similar to the move from JT65 to FT8 on HF. The problem is finding a suitable laptop that is light enough and small enough to be easily transportable yet powerful enough to cope with the latest modes with some capacity to spare. Some research required!

73, Gerald

Make me remember nice souvenirs.
73 QRO



the JT65/FT8 move is a good point. If you have a WSJTX/FT8 setup running successfully (RX/TX), MSK144 should also run. After thinking it over I am almost sure that the limiting factor in my set up wasn’t the cheapo external soundcard*. Any portable computer from the past 15 years should do. If WSJTX runs. If you look at sthe specs, any sound card from the early 2000’s onwards has had a sampling frequency of 48 kHz or more. Plenty to decode a signal containing frames of 0.072 s duration.
What I want to say is, don’t worry too much about the hardware. Except the worries are about schlepping an old weighty laptop up the summit. :wink:

*.I connected the sound card to the tablet computer using a micro usb hub. It is much more likely that the micro usb hub is the faulty part rather than the external sound card. I will replace the hub by a discrete adaptor and see if I can find a local FT8 vhf station willing to do some tests with me in MSK144.


thank you, listening to your QSO’s I recall a meteor storm in the late 1990’s. I intended to operate portably but the finals of my IC-706 blew the weekend before the storm. Giving the rig to the local radio store for a fix, he lend me a new and shiny FT-847 for a few days to be QRV during the storm. Shame I dind’t dare to take it out for a portable activation. So I sat at home in the shack with a 4 ele yagi in the attic instead of being on a hill. I didn’t manage to make a single QSO but what I heard over hours was overwhelming and more like sporadic E than MS.


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