In reply to 2E0XSD:
Hi Colin
That plug is the wrong size - IIRC you want a 1.7mm/4mm plug for the '817. Should fit the 290 though. You’re right, the positive to the outer on the 290 is a recipe for disaster. I use a 2A fuse in line to prevent the arc welding effect. And mark the lead VERY clearly so it doesn’t get plugged into anything else…
73 de Paul G4MD
In reply to all:
Well I’m delighted to see almost everyone still lugs their 817 internal pack/cells up and down the hills with them even if they have no intention of using them! I thought it might just be me.
I think I’ll dump them from mine as they haven’t been charged for a few months. That really is daft; carrying a load of cells of unknown value with me 
Andy
MM0FMF
In reply to G4RQJ:
Thanks Rob,
Glad to hear the 9.6v batteries power the 817 OK, I’m thinking of adapting the FT-290R to take one internally and free up a bit of space to fit a TNC (a little project I’m working on) and a spare to connect externally. I could also use the same batteries to power my H-520 (so it runs full power without issues). Then if I get an FT-817 in the future I just need to make up another cable & I already have the power sorted.
No need to apologise about missing me, it was very spur of the moment, just taking the opportunity to take the Dogs for a Walk (with radios) while the weather held.
I am fully aware of the addictive nature, so I’m sure you will catch me on a hill somewhere fairly soon.
73,
Colin.
In reply to G4MD:
Thanks for that info Paul,
Yep, I’m pretty sure it is right for the 290. I will keep my eyes open for any 1.7mm/4mm ones and post here if I find any.
73,
Colin.
In reply to 2E0XSD:
The 817 is different to many KenIcoYas radios in that it will produce 5W with low voltage supplies (c. 10.5V) and does not need 13.8V to do so. The FT290 is a very different kettle of fish and is rated at 2.5W out only when supplied with 13.8V. IIRC it is only about 1W when using the internal batteries. This might not matter to you but you should at least be aware of it.
Andy
MM0FMF
In reply to MM0FMF:
Thanks Andy,
I did realise that as standard the FT-290 doesn’t run full power on internal batteries.
I think mine has been tweaked to run the best it can. It measures 2W on charged batteries which drops to 1W just before it becomes unusable. It puts out about 3W with a 14v supply (which I rarely bother with).
In reality I find it works really well unless in a pile-up when it just can’t compete with others running more power and the built-in batteries last longer than I can.
73,
Colin.
In reply to MM0FMF:
So if you do have an 817 and external supply, do you still carry a
viable interal battery (AA or whatever) with you as well?
No, I took the internal batteries out as soon as I moved to LiPOs.
73
Richard
G3CWI
In reply to MM0FMF:
I think I’ll dump them from mine as they haven’t been charged for a
few months. That really is daft; carrying a load of cells of unknown
value with me
Yes, in your case that’s the right decision Andy - take only kit that might be useful to you. If you aren’t keeping the pack charged up, then it just ballast. I carry only useful kit and that goes for spares as well as the main kit. Whether I use it or not is irrelevant - like the bothy bag I’ve carried up 250 summits. Once I leave it out the pack, that’s when I’ll need it. Murphy is watching!
73, Gerald
P.S. There’s absolutely no truth in the rumour that I carry a 12V soldering iron with me!
In reply to G4OIG:
P.S. There’s absolutely no truth in the rumour that I carry a 12V
soldering iron with me!
Ah, it must be a butane iron, then!
73
Brian G8ADD
In reply to G8ADD:
Ah, it must be a butane iron, then!
I have actually considered purchasing one of the small gas irons. Very useful to sort things out without involving the depletion of valuable electrical power. Logic dictates though that running repairs during an activation are not the best way of dealing with issues when they arise - direct replacement is always the best and I have used spare cables and even spare rigs on a number of occasions.
73, Gerald
In reply to G4OIG:
I have a 12V iron… I don’t think it would melt butter never mind solder. It has no thermal mass so any wind/breeze cools it down to useless straight away. The gas powered ones are significantly better IMHO.
Andy
MM0FMF
In reply to G4OIG:
- direct replacement is always the best and I have used spare cables
and even spare rigs on a number of occasions.
IMO SOTA activation is not such a mission critical operation that backup is needed. You can always climb the mountain again some other day.
For soldering I use normally at home a cheap 12 V iron. In addition I have also high power iron 230 VAC and small portable iron that operates from 3 AA batteries. All this is of course from the stone age, since now you need hot air tools for the SMD components 
Back to the original question, the external SLAB is actually useful when operating below -10 C. The standard NiHM 1400 mA does not give enough current to the transmitter any more at these low temperatures.
73, Jaakko OH7BF/F5VGL
In reply to F5VGL:
You can always climb the mountain again some other day.
True Jaakko. I can always drive the same 900km to get to the mountain as well! Carrying an extra kilogram of kit is far more preferable to the drive.
… below -10 C. The standard NiMH 1400 mA does not give enough current to the transmitter any more at these low temperatures.
As indeed I found out with my C520 handheld on standard 2500mAH NiMH cells when it was down to -6C. The external LiPos powering the 817 were still going strong though. However, I must remember this issue as I now use a LiPo / NiMH combination pack to power the 857.
73, Gerald
In reply to G4OIG:
As indeed I found out with my C520 handheld on standard 2500mAH NiMH cells
when it was down to -6C.
My Icom IC-80AD handy has a LiPo pack and when it’s cold it won’t let you select high power. (Cold = below 0C). The capacity of LiPo cells does drop a lot when they are cold yet I’ve not had problems with my my external packs when it’s been -10C. I can only assume that the handy has detected the low temperature and is limiting the output power to protect the cells from heavy discharge.
There’s no such protection for my VX1r (14 years on the same LiIon cell). The VX170 has a NiMH pack that seems to have enough zing in it to jump start an ocean liner, I’ve never noticed that affected by cold. And you can use the VX170 to hammer tent pegs into frozen ground. If you hit the pegs just right you won’t damage them… nothing marks the VX170’s case! 
Andy
MM0FMF
In reply to MM0FMF:
The key factor is that the temperature of the cells will probably not be anywhere near the ambient temperature. The nominal internal temperature of my backpack during last winter was around 11C - I know as I carry a thermometer with me. Wherever possible I have avoided exposing the LiPo battery packs to the air for any length of time and have kept them in their bubble wrap covering within the pack. An outer pocket was sufficient for the LiPos on their own, but I might need to rearrange things in order to keep the LiPo / NiMH combos inside the backpack itself.
As for handhelds operating below zero, the C520 is a comparative brick - the term handheld refers to 1990’s terminology! I carry it in a pocket at the top of the pack and it would not therefore have the benefit of being kept warm within the backpack. Being unaware that NiMHs don’t perform under low temperature conditions, it was quite a surprise to have the rig die on me. Of course I never had an issue with the 817 on its internal battery as it was operated from within the backpack.
73, Gerald
In reply to G4OIG:
The nominal internal
temperature of my backpack during last winter was around 11C - I know
as I carry a thermometer with me.
Do you keep the thermometer inside or outside your kitchen sink - and do you carry a spare of either?
73
Richard
G3CWI
In reply to G3CWI:
I only carry a single kitchen sink. If it blocks on an activation I have to wait till I get back to the car to unblock it! 
Andy
MM0FMF
In reply to ALL:
Drear friends,
During my SOTA vacation and expedition this year to Rhodes island where I hope to be able to activate 5 summits.(See Qrz.com-ON6DSL) I want to use my FT817 but I want firts purchases a LiPo battery pack.
Can you (someone) advise me what I can best purchases.
I thought of the following … 11.1 V 2500-3500 … The 14.1 V series I dare not buy because I think the voltage is too high.
PSE help … info.
73
Luc ON6DSL
In reply to MM0FMF:
I only carry a single kitchen sink. If it blocks on an activation I
have to wait till I get back to the car to unblock it!
Shame on you Andy, it clearly says in my 1823 edition of “Hillcraft for Gentleman Explorers” (expurgated version) that one of the indispensible pieces of equipment to be carried by the third bearer is a sink plunger. Such an oversight could put the whole expedition at risk.
I do sometimes wonder whether Gerald only takes me along to carry the patio heater and barbecue though…
73 de Paul G4MD
In reply to ON6DSL:
Good evening, Luc.
Many of us are using 400mAh 3S LiPo packs of Chinese origin. Mine is labelled WinForce. The voltage is ideal for the FT-817 but as you say, the 4S would exceed the spec for the radio.
It’s difficult to be certain about battery life because there are so many variables, but I think it’s safe to say that unless you insist on using FM with it’s higher current drain, you should have no problem doing five activations on one of these packs.
After five activations earlier this year on a backpacking trip, the battery was only 25% discharged however to confuse matters, I was also re-charging the pack at around 300 mA during two of the activations using a solar panel. You might even manage with a smaller battery but the 4000 mAh are competitively priced and having load-tested mine, I can say they are excellent.
Oh, and to those contemplating buying a gas soldering iron, I would urge caution. Mine is very difficult to light when it’s cold. Butane, you know. The caravanner’s nightmare in winter.
73, Richard (still pining for the hills…)
