$127 to replace them…could buy a QMX 5 band CW and FT8 rig for that!

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I use MX-P50M and mcHF QRP. When I feed it with 5W it gives out about 35W but with input of 10W I get 50W out. QRP rig and PA is the most effective way to work portable as it makes the most efficient use of your battery. The only downside to MX-P50M is you need to remember to change bands.

As for vertical antennas and counterpoise, a lot depends on the local ground conditions. I find EFHW4010 as inv-L with transformer at 2.5mtr and apex at 9mtr works better than 1/4wl vertical but you need to be mind full of lobes and their maximums in relation to main DX azimuth.

Here are radiation patterns at 10deg for 20/15/10m bands, end of the antenna is pointing up (North)

GL 73 Marek


Me too. I used to run a FT-857D for SOTA, mainly around 30 watts output, but the relatively high current draw on receive was an issue for an extended stay on a summit. I moved back to my FT-817ND and added a MX-P50M amp which is much better. I rarely drive it to more than 30 watts output.

My most QRO activation was actually on 2m when I was on Craig y Castell GW/NW-074. I ran the 817 into a 25 watt linear to drive a BNOS LPM144-25-180 linear. There was a bit of battery sag with the SLAB I was using so I settled for 125 watts out to the 5 element and worked Don G0RQL by backscatter (to get around Cadair Idris - Penygadair GW/NW-009) along with a number of other stations. A bit of power can be useful at times…


I wouldn’t bother.
I find most of my projects work fine up until the point I try to box it up.


After a couple of 2M FM disappointments running QRP, I got a Kenwood TM-281

It’s not too heavy (1.3Kg including the mic), it’s amazingly robust and has great sound quality on Tx and Rx. RX current is OK at 0.2A. I run it from a 3Ah LiPo.

When needed it can push 65W but I usually run it at 25W which pulls about 7-8A on transmit. That gives me about 1 hour of QSO time.



Just noticed that there is a new ‘field’ version of the Yaesu FT-710:



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Worth putting up with the harsh sidetone on CW for the rest of the radio which is good. The RX is outstanding for the price point and the ergonomics are very good, but I am Yaesu born and bred hihi. The AESS speaker remains in the box in my loft Mark. I won’t be carrying it on my back to a summit any time soon. It might go down to G/TW-004 next year for a camping table activation on the “summit” though!

73 Phil G4OBK

PS The free shipping suggests ML&S might be getting stiff competition from the expansion of Moonraker. I bought the £8 handle for mine, as I want to use it when we go somewhere in the car or hire a cottage / Gite

PPS The £8 carrying handle is the same one as on the FT-991A but that rig comes with the handle included

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Wouldn’t you have thought for the sake of £8 Yaesu would have fitted the handle to the Field version?

73 Phil


There is proper markup for the dealers on accessories etc. So the dealers all sell for the same price on the base radio and make some profit. The real profit comes from selling you the accessories. As you don’t need to buy CW filters any more that’s one profit line lost.

Turning the power up is one way of doing it.

But there are other methods making the signal travel further, get it more widely heard, and make large numbers of QSOs.

Using exclusively 5w rigs throughout my 21+ years doing SOTA, I’ve slowly but surely sussed out how to use the propagation forecasts - and live propagation/activity reporting (eg DX Heat) to select my band/mode for optimum results for the time of day I’m activating. Or the other way round - select my time of day for the desired band of operation! Use of efficient modes such as CW and FT4 give my TX a little more “poke” too! Oh - and resonant antennas. Monoband verticals with groundplanes are unbeatable (IMO).

For many years I thought my 5 watts was a disadvantage - but it was my relative inexperience and understanding of propagation that was the problem. I now have no desire nor need for anything other than QRP for SOTA activating.


Yaesu FT-90 for the win! I’ve always hankered for one.

Must do something about it but the toy fund is severely depleted having had to buy a new laptop and a new phone. :frowning:

I think I could have qualified the summit today with 5W but 50W was much more fun.

Ended up with contacts all over the place just because people had heard me calling with a reasonably strong signal, some chasers got a summit they hadn’t managed to work previously (and some WAB collectors got a new square) and when tuning around at the end I noticed some of the chasers had stayed on and were running pileups of their own so it seemed like it generated a bit of activity which was nice to hear.


4.5Kg - twice the weight of an 857d. No thanks.

I was seriously considering the FT-710 myself even though touch screens hate me, but I notice that in the USA it has just had a major price drop so I am holding fire on a decision to see if it happens here.

If the walk is fairly short I use an FT-857D, and otherwise an ft-817ND. My rucksack has a padded back and a back pocket inside that the 857 fits in nicely so it is well protected. For antennas I use a W3EDP on the lower bands and a vertical with elevated radials on the higher bands.


I’m fairly certain that you can plug a mouse into it (avoids using the touch screen for most things) if you are not allergic to mice!

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Hmm…that’s good to know, thanks!

Yes, Adrian @G4AZS is correct. I only checked this out this afternoon, as I was setting up my FT-710 with my new (to me laptop) for future use on data modes.

I needed to use the square type B USB port on the back to interface with the laptop for audio, CAT and PTT. But there is also an extra oblong type A USB port. To confirm it worked I plugged my Logitech wireless USB mouse dongle into the type A FT-710 port and I found that I can use the mouse pointer to change the radio settings rather than the touch screen.

Whilst testing the set up in the last 30 minutes I just worked SOTA stations @VA2EO/W1 (10m) and @N6AN (12m). If you read this guys apologies for my keying. I was testing out ELEKEY-A mode on the FT-710 and made several mistakes. Sent K and I got M, so VA2EO came back to G4OBM until I resent my call correctly a few times! ELEKEY-A mode does not suit my fist! I changed to ELEKEY-B mode and no problem, no mistakes then.

I hope the UK price falls for you Brian on the Field version and you get one - the AESS speaker is not worth paying the extra money for. I think Yaesu also have the cashback deal still on as well. They do pay up eventually, in my case they had to be reminded as they hadn’t paid up by the end of the period as they stated they would. Several other hams had the same issue, but a few of us complained and once the logjam of paybacks was cleared they seem to be paying back regularly.

73 Phil G4OBK


Hi Rick @M0RJC, I now have two Kenwood TM-281’s, both bought secondhand after being so impressed by the Kenwood TH-K20 handheld. I have one at home and one in my car. I have been tempted to take one on an activation, but generally seem to be able to work the horizon with a decent antenna (identical to yours) on 2m FM using the TH-K20.

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Hi Kevin

One thing to watch for : I got reports of a “ticking” noise on my signal. Turns out it’s the microphone key scan, which is multiplexed, crossing over to the mic signal line.
If you don’t need the mic keys (something I don’t like anyway) the easiest fix is to blank off the offending pin on the RJ45 (pin 1) using a bit of insulting tape.

Otherwise very happy with it




Here’s something else to check for.

I’m designing side frames and prop feet (to 3d print) for the TM-281 and I noticed a major problem. See the pic below. It seems the power wires are a bit stiff and the insulation breaks at the bend point where it enters the strain relief sleeve.

I guess it’s fine for a mobile install, but the inevitable flexing with portable use has caused a problem !

To make it harder to fix the strain relief bush is heat sealed onto the cable, but it locks into the rear of the casting so it needs to stay. Opening up the unit to get access to repair it I was very impressed with the build quality. Everything except the front panel is on a single PCB which is attached to the chassis with no less than 16 screws.

Long term I may incorporate a new power cable with Powerpole connectors into the printed frame.

Edit : It looks like the cable is available to purchase as a spare part : https://www.pacparts.com/part.cfm?sku=881H07-4410-72