IC-706 for SOTA

Hi all.
Has anyone used the above radio out in the field? I no longer have my ft-817 and now have a 706 which I could use for portable use. I have a 7ah gell cell which I have used previously but am thinking the current drain from the 706 would prohibit it’s use portable. I wouldn’tuse the 100w but restrict myself to around 20w. Any thoughts, experiences?

Many thanks
Tim - G0WBR


I used my 706MK2G with 2 x 7AH SLABs to activate both G/CE-001 and G/CE-003 on the same day a few months ago (most of my contacts were on 2m but also a few on 70cm and on 10m), however I suspect that the cells wouldn’t have lasted for a G1INK style multi-band, lots of contacts activation.

Just don’t do what I did when I took the radio out of my bag back in the shack ! - I dropped it and broke one of the front panel controls.

Stewart G0LGS.

In reply to G0LGS:
Hi Stuart
Thanks for the reply. What sort of power were you using? I only have one of those batteries so do you reckon a couple of hours at 20w on 2m / 40m ssb be feasable?


In reply to G0WBR:
Hi Tim

The 706 is OK although the RX current is very high.

My 706 II G was good for 64 QSO’s (CW and SSB) at 25W using a 17ah SLAB over 2 hours yesterday before I had to stop.

The 706 is not so tolerant of voltage drop and you can “hear” in headphones when the SLAB voltage is dropping too much for the rig. e.g the side tone starts to get a bit rough on CW.

However I have quite happily used my 7ah SLAB with the 706 for activations lasting more than an hour with power at 10 watts or so.

73 Marc G0AZS

In reply to G0AZS:
Thanks Mark I appreciate the reply.
I may have to start looking for something with a little less current drain. I thought the receive current would be a limiting factor.

Many thanks

In reply to G0WBR:
Part of the Rx current is due to the PA stage taking between 350 - 500mA. Mine takes nearly 400mA even when supposedly powered off. Even Land Rover batteries go flat if I leave the radio connected for more than 1 - 2 weeks.
As Mark says they are also rather intolerant of voltage drop. You will find the FT-857 better in both respects.

73 Graham G4FUJ

Hi Tim, why did you ‘leave’ the FT-817?

73, Mike, DF2OK

In reply to DF2OK
I don,t know, very silly i know. I thought i needed more than 5 watts. If anyone wants to swap their 817 for a 706 plus at7000 auto tuner let me know.

In reply to G0WBR:
Hi Tim…
First Happy new Year to all…
I use the 706MK2G 2 years ago and it work´s fine. With an 7ah slab i made around 80 qso on 2 summits with 20W. Now I use the IC7000 and 12ah. This is good for more then 100QSO with 50w.
Hopefully this can help you.

best 73 de Tom

In reply to G0WBR:


For reference, I easily run 2 hours of 2m / 70cms SSB on a pair of 4AH LiPo’s running my FT-817 to a Microset dual band linear giving 22W output at 12.6V starting voltage. Even at a fully drained 11.1V I am getting 15W or so out.

All I need now is the confidence to not carry a spare 4AH battery… but at 287g apiece including the connectors I’m not that concerned. You certainly won’t find me hauling a 17AH SLAB around like Marc!

If I were you, I’d certainly be looking for an FT-857 - wish I had gone that route myself from the start.

73, Gerald

In reply to G4OIG:

All I need now is the confidence to not carry a spare 4AH battery…
but at 287g apiece including the connectors I’m not that concerned.

Snap! The fact I’ve saved a kilo is good enough for now. With a bit more experience I think the single LiPo day will arrive.


In reply to MM0FMF:

I would certainly recommend LiPo’s to Tim if he sticks with the 706 - they don’t lie down and die like SLABs do and should give better performance even with a rig “idling” at 400mA. It might be worth investigating a 4 cell battery which would give 16.8V fully charged and 14.8V discharged so dropper diodes + switching would be required, but it could be the way to go.

73, Gerald

P.S. I’m now left with wondering what to do with my SLABs - the 12AH one is a useful shack back up PSU, but the 3.3AH ones are of little use. If anyone wants them, meet me at a summit parking spot - I’m not carrying them up the hill to meet you there!

In reply to G4OIG:

…should give better performance even with a rig “idling” at 400mA.

Aha… but just remember that the 706 “idles” between 1500 and 2000 mA in RX!

Shocking really but it does get nice and warm even when monitoring. My keying hand stayed toasty warm yesterday with the paddles magnetically mounted on top of the 706! :slight_smile:

73 Marc G0AZS

In reply to G0WBR:
Hi Tim,
I used FT857/10W CW and 7 Ah Accumulator for 1 year. It is good radio for SOTA, but it takes only about 90 minutes of the work when battery is new. When is frost, working time is shorter. Sometimes I have problem to activate 2 summits per day. Radio+Accu+ATU weight about 7 kg. Now I have QRP radio PFR-3 – all in one. I Use 2.2 Ah accumulator and I am able to activate more than 10 summits (500 QSO) and weight is about 1 kg.
Jirka OK1DDQ

In reply to G0AZS:

Aha… but just remember that the 706 “idles” between 1500
and 2000 mA in RX!

Phew, no need to carry a patio heater on an activation then! :wink:

If I had a 706 I would still be using LiPo’s rather than a SLAB on an activation. LiPo’s are made to provide high currents and an idling current of 2A would be no real issue. The 4AH batteries that I use are rated 15C which means they can produce 60A. Whatever we do to them in amateur radio service is unlikely to seriously challenge their capabilities - apart from shorting them out, that is!

73, Gerald

In reply to OK1DDQ:

Dear Jirka!

The lighter your set-up is, the more comfortable your walking tour will be. However the lighter your set-up is, the less your power and likely the less QSOs you can make. On the contrary the heavier your back pack is, the more power you have and the more your result will be. Therefore you need to compromise between your comfort and your (enjoyment) result.

Even I have been DXing since 1968. I worked with FO station at 21 MHz CW working with 2W fed from a solar cell. I also worked 5W station from W1 at 3,5 MHz. I had never before gave 329 report for a QSO partner, but since I have been chasing SOTA, I did it several times, because I felt just like as if I were making meteor scatter QSOs at 144 MHz… Even if the partner was located in the dead zone, sooner or later but I received 2-3 letters at the verge of hallucination, 5-10 seconds intermission, 2-3 letters again… But at least I could hear him! It’s merely question of persistence and we can complete the QSO!

I used to be disappointed spending 20-30 minutes at my radio but hearing nothing at all from a station operating 100mW from a pair of AAA batteries fed into a bike spike stuck into the ground… In case of this extent of QRPPP signal whatever QSB peak may come, it simply can not penetrate from the dead zone, there’s no way to establish a QSO… Furthermore the field strength drops proportionally to the second power of distance…

I am sure that a pair of tourist boots weight at least as many as a 7Ah battery. A bottle of tea or water as a 5-10W RIG, a binoculars or a camera as a half wave dipole. A BigMac sandwich as a QRP antenna match… I didn’t even mention pullover, a raincoat, a cap or hat and sun glasses, etc. :slight_smile:

A SOTA activation is not a “DeeJay, Hawaii, CocaCola, sunglasses” type of action! I try to share the inconveniences and not to push all those on the chasers’ side of the table. That is I do rather go slower, but I carry more weight and try to provide 1-2 S grades stronger signal. Despite of this I received 119 (Hi!!! Nonsense!) report as well. :slight_smile:

This is my opinion, which may be wrong, and may be subject to dispute. I did intentionally put it sharp in order to make all of us think it over and make a reasonable compromise. I hope: it did not hurt anybody!

Joska, HA5CW

In reply to LA8WF:

Dear Jon!

I used to go portable for VHF contests in the 1980s for several years and my experience was that one big capacity battery is better than two half as big. On the one hand it gets low slower and the percentage of non-usable packaging (housing) is lower on the other. Finally you don’t have to deal with changing! (In winter time, considering cold [that is more vulnerable] fingers, this is a significant aspect!) Therefore I suggest you trying the next bigger product, the 12Ah ones weighting about 5-6 kg.

73: Joska

In reply to HA5CW:

I just weighed my Yuasa NP12-12 (12v, 12 Ah) battery and it was almost exactly 4 kg, about a kg lighter than my 13 Ah battery by another manufacturer. My FT857D, battery, tuner and antennas come to 7.5 kg which is less than the equipment I used to carry for snow and ice climbing…anyway, I’ve never run a 12 Ah battery flat on the hill in an activation except once when I had forgotten to charge it up!


Brian G8ADD

In reply to G8ADD:

My 12V 12AH SLAB weighs 4.2kg Brian. By comparison 3 x 4AH LiPo’s weigh 0.86kg. As far as I am concerned it is a no-brainer when choosing a power source, particularly as amphour for amphour more operation time can be obtained from LiPo’s relative to a SLAB. The last time I used the 12AH SLAB was on Moelwyn Mawr GW/NW-016 and my backpack weighed in at almost 17kg. That would have been a more reasonable 13kg with LiPo’s and my day would have certainly been much easier.

If Tim is happy with the operation of the IC-706, I can certainly recommend the purchase of a couple of 4AH 15C 3S LiPo’s at around £23 on eBay or if he opts for the 4S ones the cost is £27. With an inexpensive charger at less than £10, it is not too much to give the rig a good work out before deciding whether to go back to Yaesu.

73, Gerald

In reply to G8ADD:

I just weighed my Yuasa NP12-12 (12v, 12 Ah) battery and it was almost
exactly 4 kg, about a kg lighter than my 13 Ah battery by another
manufacturer. My FT857D, battery, tuner and antennas come to 7.5 kg
which is less than the equipment I used to carry for snow and ice


Maybe that accounts for why you get out so infrequently compared to Gerry!