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C4fm 4 sota


Unlikely to catch on but why not give it a try?


Hi Tom,

Sorry but could not RX you on WB-002 this morning on C4FM on my FT-2 on an external collinear at the works QTH about 7 miles NW Shrewbury. Maybe on some of the other WB’s at some point in the future. I’ve easily chased Stiperstones and Corndon from the office doorway with the HT on it’s stock antenna, before installing the collinear.

I run a simplex C4FM / WiresX gateway MB6SY at the home QTH in Shrewsbury but that’s no help for SOTA.

Steve G6UYG


It might well be of some help if someone clever sets up something akin to the CQ-UK system which now links D-Star, DMR, C4FM and FM to a single room.


It can - and does link to CQ-UK. I need to get my FTM-400 back in the vehicle, it’s the only problem in having a new company car every 4 years, taking the radios out and re-installing them. :grin::disappointed:


I’m taking a drive out now. I will spend some time in the car, at a high spot seeing if I can connect into WiresX and ultimately CQ-UK (27793), but I haven’t really got my head around how it all works yet.

If successful, I will get to a SOTA summit and first check into the CQ-UK room to announce I’m there. If unsuccessful (as I anticipate at this stage), I will simply climb the hill and call CQ SOTA on 144.6125MHz C4FM (Fusion).


Wednesday 21st February 2018 - The Cloud G/SP-015 - #996

After arriving at the Cloudside parking area on Red Lane, I sat in the car for over an hour seeing if I could get my Yaesu FT-70DE going on Wires-X and into the CQ-UK group. After a bit of fumbling around not-really-knowing-what-I-was-doing, I got in, and spoke to the Wires-X / Digital Voice guru Stuart M0SGS. Eventually, around 2220 UTC, I donned jacket, hat and headtorch and went for a walk up to the summit.

Four QSOs were made on 2m Fusion (C4FM) - G3CWI, M0WBG, 2W0JYN and MW6SHJ. Additionally, 2E0IXM and 2E0LKC were worked on 2m FM (analogue).


I first bought a d-star radio about 12 years ago when it was introduced into VK - never particularly happy with audio quality. Then bought DMR radios for WICEN use (our ham emergency comms mob) and then P25 on 2m.

Of all of these I have a preference for DMR - and for multiple reasons. Firstly it is not limited to one manufacturer, secondly the audio sounds to be better to me and finally the potential for data and voice at the same time. One of our locals has been looking at this as it would be very useful to be able to send low rate error data whilst still being able to pass verbal messages on the same radio.

My DMR radios despite being of chinese origin are actually good quality (you get what you pay for they were not particularly cheap) - they meet the fairly strict VK requirements for operation on commercial (i.e. non amateur) frequencies and have proven to have a very good receiver even in high RF environments.

Not completely ruling out fusion, but I really dislike manufacturer specific radios - I really wish that they could agree on a common standard mode or alternatively produce a radio that the user could decide what digital mode they wished to use. Living in hope!



Seems like you made that rather harder than it should have been. In a nice warm shack with the internet at hand for tips, the same process took 2 minutes.


I think C4FM is an open standard (developed by Yaesu but freely available). Various hotspot devices support it but currently there are no other radio manufacturers. To that extent it is manufacturer specific.

Cross-mode rooms supporting all the various modes (and analogue) are already in existence.

Common standards??? That’s the thing about standards, they are far too common.


The specification is published. System Fusion will be trademarked so anyone selling something compatible will have to get permission from Yaesu to use System Fusion in the name. They’ll be able to say compatible with System Fusion ™ and that it’s Yaesu’s trademark.

Lots of stuff made in China is of excellent quality. Apple iPads/iPhones,Macbooks etc. My Yaesu VX-170 and FT-817s are made in China. There is also huge amounts of tat and rubbish made there and sold to us cheaply as well!


Next C4FM SOTA activation coming up in half-an-hour or so. May call into CQ-UK room first.


Thursday 22nd February 2018 - The Cloud G/SP-015 - #997

Lovely sunny afternoon, but very chilly on the summit. No WIRES-X connection available via the MB6ISK node this time, so I didn’t get into the CQ-UK group room after all. I may be paying the price for opting for the budget Yaesu FT-70D HT - it doesn’t appear to have the option to push a button to seek out all available WIRES-X connections. I’m clinging to a hope that I’ve just not yet discovered that feature, but I fear it isn’t available on this rig. Unfortunately the supplied supplementary manual for the WIRES-X additional function is very badly written and seems to be full of errors and omissions.

So straight onto 144.6125MHz C4FM it was, and straight back came Ian G0CTO. This resulted in a lengthy QSO about which frequencies should be used for C4FM. Ian’s view was that 145.375MHz should be DV calling with the standard 2m FM frequencies also used for C4FM QSOs. So far, I myself tend towards the preference of the DV ops in South Yorkshire, to utilise the all modes section from 144.6125 to 144.7875MHz, avoiding of course the 250Hz multiples which are Raynet frequencies.

Next up on Fusion was Neil M0WBG, who could report that whatever the issue was affecting his reception of my C4FM signal the previous night, was thankfully no more.

That was all on Fusion for this activation, but ten QSOs were added on 2m FM. Thanks to everyone that called in.


I think MB6 indicates that it is an attended gateway - only available when the keeper is on site.


Totally Agree Tom, if the 991 manual is anything to go by it is more Confusion than Fusion !
This simpleton requires a step by step guide to setting up and using CF4M and Wires X.
Is there any such guide available ?
Neil M0WBG


The smaller the screen, the harder it is to make a user interface that works and is easy. This was something Nokia understood. Before smartphones, you could buy a new Nokia and the new software worked the same as the old. There may be more features and options, but the basic operation was incremental across updates and models. It costs huge amounts of money to write software like this, if it didn’t, the consistency of interfaces would be standard across all software. But it isn’t like this because it is expensive to do this right.

The problem with things like Wires-X is you have to learn how it works on the air using the system complete with vagaries of propagation to your node and whatever. Really you need a Wires simulator to play with so you can learn how it works in your own time and practice doing things.


Yeah, this is the thing I really like about DMR, it’s really got a very well spec’d data/packet format. You get low-rate in-band data during the synchronization blocks. Or you can use the second time-slot to do full-rate data either with three different levels of FEC and confirmed+unconfirmed. From a data link layer it’s really well designed and defined. All while still preserving voice capability across a channel.

Basically once you have a DMR repeater setup you in theory get data for free. The only thing is few radios support it now.


More DV - Fusion - C4FM SOTA tomorrow (today - Friday). This time off to the Clwydians. Late start so just doing the main two - NW-051 & NW-044. Soup will be Baxters Royal Game.


Friday 23rd February 2018 - North-East Wales

The late start was mainly as a result of needing to drop Liam off at the hospital for his Friday volunteering he does every week with the dementia patients. He’s certainly giving lots of himself to community stuff while he’s out of work - Sunday night at 10pm he has his radio programme on Upload Radio (online and on DAB in NW England) - https://s3-eu-west-1.amazonaws.com/uploadradio/video/940e29f0-17f6-11e8-915c-3b20bb587e44.mp4 - then on Monday at 11pm, he begins his weekly “Late Night Liam” show on Canalside Community Radio (Macclesfield & Bollington) 102.8MHz FM.

Then I had to chase up why the mechanic instructed by the 3rd party insurers to fix the damage done to me car in Shropshire three days ago - was not actually doing anything. So at least five hours later than I would normally choose to commence a SOTA day out by the time I got going!

I could make the time back with the correctly programmed satnav, familiar hills and a host of other shortcuts. These were:

  • Walking in trainers - not bothering to change into boots.
  • Not carrying a rucksack - eat and drink in the car between summits.
  • Just use handheld & rubber duck - so no radio equipment or antenna to “set up”.

To be honest, all this was fine throughout the day. It made me think that I’ve been making this SOTA business harder and more complicated than it need be over the past 16 years!

Foel Fenlli GW/NW-051

I parked my £1.50 to park at Bwlch Penbarrass then set off up Foel Fenlli. I’m sure it gets steeper every year! Not bothering to take my trekking poles was a mistake and hampered my rhythm going uphill, but the descent was fine, surprisingly. Mind you, it was absolutely bone dry with no slippery sections.

The weather was bright and dry, but deathly cold. At the summit I made just five QSOs, 4 on 2m FM and one on 2m C4FM (Fusion). The it was back down to the car for a warm-up and some Royal Game soup.

Moel Famau GW/NW-044

I saw a chap in motorcycle leathers approaching the car. It was Roger MW0IDX, who I hadn’t seen for ages. What a fantastic surprise. We had a good natter for a while before Roger had to go.

I began my walk up Moel Famau, but soon got that feeling that I’d “hit the wall”. It became a real effort to keep moving forward - I was shattered! This took me a bit by surprise, but I put it down to not having that much sleep the previous night.

Upon reaching the summit of Moel Famau, I made straight for the top level of the Jubilee Tower ruins, in order to achieve the optimum take-off for my FT70-DE handheld. This activation was more productive, attracting 21 QSOs - 5 on C4FM and 16 on FM (analogue).

On the way down I wrestled with the thought of squeezing in a third activation for the day. I didn’t have the energy for Moel Gyw GW/NW-053 or Penycloddiau GW/NW-054, plus the sun was starting to go down. Mynydd y Cwm GW/NW-076 would have been an option but I opted for something back in the direction of home.

Hope Mountain GW/NW-062

My satnav didn’t land me anywhere near to the summit or adjacent farm, but at least in some roads I recognised, so I was able to find my way easily enough. I drove into the farmyard and waited for one of the inhabitants to notice me and come and ask what I was up to. David wandered across after seeing to his milk herd, and thankfully recognised me. Permission to access the trig point (in a private field) was granted immediately, and he even suggested that I drive up to it across the fields!

I declined this for several obvious reasons, but took him up on his invitation to park in one of his fields. I now had a fairly easy five minute ascent on foot - apart from the bit where I need to roll under an electric fence. Seven stations were worked from the summit - six on 2m FM and one on 2m C4FM. My hands were numb from cold by the end of operating though!


There will be at least three summits on 2m C4FM - Fusion this morning, so quite possibly a significant spike in DV SOTA! Chasers with System Fusion - fill yer boots!


I wondered why I did not hear you? Your use of a Rubber Duck explains it Tom, on a cold day like yesterday I can certainly see why that approach was employed though!

Connected the larger FTM100D with 50 watts to my 4 ele vertical beam at 30’ AGL, normally can get the 2 x 2 point summits you went up, but with you using a rubber duck I had no chance!

Have you got one of these in your arsenal? They seem to give much better performance and can fit in the other coat pocket if you go for the HH only approach

Original Diamond - https://www.ebay.co.uk/itm/Diamond-RH-770-2-70cm-Supergainer-CL-Telescopic/173169594846?epid=1987204494&hash=item2851b651de:g:HZ8AAOSwmSdajDBI

or cheap Chinese variant

Just a thought??


Matt G8XYJ