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FT-857D Portable Help


Hi all,

I’ve been successfully carrying out SOTA activations using my trusty FT-817ND on and off for the last couple of years. I’ve now brought myself an FT-857D to give me a bit more power and hopefully work though some of the noise on 40m at weekends!

Does anybody have any advice on batteries. I’ve tried out with a 7.2Ah SLAB which seems okay and worked for an hour or so without problem but I’m not convinced it would survive too much abuse in the rucksack I also tried a Li Ion battery 9800mah which was a waste of time and money. Incidently why is the FT-857D power connector so enormous?

My other problem is protecting the unit in the field. It won’t fit in my Lowe Pro bag that I normally use! Any advice would be gratefully received.



In reply to M0ZZA:

Search the reflector. There’s several hundred posts on batteries and lots of useful advice. After you’ve done that and digested all that info then if you have questions, post them and everyone will be keen to help you further.



Thanks. Will look further.



In reply to M0ZZA:

Hi Tony, the 7 Ah SLABs seem quite robust, mine have suffered no damage either backpacking or camping. One is five years old and has started to deliver less power in cold weather but I don’t think it owes me anything. I find it best to operate at about 20 watts and hold some power in reserve for marginal contacts, that way the charge lasts longer.

When Woolworths was still going I found amongst the “back-to-school” section a soft plastic padded container which would fold flat and was the perfect size for the 857, it had a velcro closure and a carry handle and is waterproof, I think it was intended to take a packed lunch and flask. It only cost a couple of £ or so, I’m sure that somebody still sells it, I’ll keep an eye open. My rucsac has a compartment between the padded back and the main compartment that the rig will slip into in this padded container so it is in the safest place.

Incidentally, the manual suggests that the operation of the rig will become erratic below 11.75 volts, but in fact it will still work well at a lower voltage - the modulation of mine starts to distort at just above 10 volts.


Brian G8ADD


In reply to M0ZZA:

I`ve used 7ah slabs for 700 odd activations without problems. Even the old ones will happily power the 857 for over an hour on full power. I cut my power lead down to about a foot long. I know this gets rid of the fuses & fuse holders which suits me as I found the holders are prone to oxidation which in turn restricts the power to the rig, resulting in a dirty signal. If you do simmilar, just remember not to reverse the polarity of the leads - surely nobody would be so daft …


In reply to G8ADD:
Thanks Brian, I’ll keep my eyes open. I did try a 12ah SLAB but decided that that was overkill and overheavy.

I tried the Icom Rucksack designed for the 703 which is super quality but not designed to carry more than the radio. I couldn’t even fit my packed luch in as well let alone waterproof, First Aid kit etc. etc.

I’ve certainly had no problems running the 857 on around 10.5 volts either. I think I’ll try a LiPO as well just 'cos I can.




In reply to M0ZZA:

Hi Tony,

I used my FT-857D for the 50MHz contest last Sunday on NW-051 using a 12Ah SLAB.
I was continually operating for three hours at 50W ssb and I estimate the battery to now be at half capacity.
For transporting the rig I take the front panel off and carry it separate to the rig in a large padded plastic food container/lunch box.



In reply to M0ZZA:

As with so many of life’s (SOTA) problems, goats are the answer:





In reply to G3CWI:

Yep. Like the idea of goats…




In reply to M0ZZA:
Hi Tony,
I often activate the summits during my business trip all around Europe. I carry two 7 Ah SLABs just in case as I can hardly make more than one summit a day and I charge the used SLAB overnight in the hotel.
I went to Scandinavia in September. First night in the hotel I discovered I have forgotten to pack the charger. Distempered I decided to give it a try and see how long the SLABs can power the FT-857 without recharging.
Well, I have made 36 QSOs from OK/MO-015, 51 QSOs from OK/OL-020 and SO/SW-004, 37 QSOs from OZ/OZ-005, 26 QSOs from SM/VD-002, 21 QSOs from SM/SE-001 and finally 36 QSOs from OK/US-017. All on CW, running 50 W at the beginning and 20 W toward the end, alternating both SLABs. The SLABs ran slowly down, but the transceiver was working well till the end of my journey.
I make no special precautions when packing the SLAB, just taking care not to shorten the lugs. The battery is pretty sturdy.
So much for the 7 Ah SLAB.
73, Ruda OK2QA


In reply to M0ZZA:

Peanut and Rooster are already into SOTA. Have you noticed that goats is an anagram of G-SOTA?




In reply to M0ZZA:

Hi Tony,

As has been suggested I would recommend only using a power level necessary to make contact. I have used a Yaesu FT897D,(basically the same inside as a FT857D), on several activations & a 7Ah Slab was more than sufficient to last several hours with careful control of transmit power levels. Of course, If I had left the TX power at 100 Watts, it would have drained much quicker.

It makes good sense to only use whatever power is necessary for a QSO, although sometimes when conditions are very poor, even 100 Watts will not be enough.

I have found that a starting power level of between 10 & 20 Watts (SSB)is normally more than sufficient to get yourself noticed on an open band under average conditions, from there you could alter your power up or down accordingly & make efficient use of your battery power, which is after all, a finite resource on a summit.

If the HF bands are not playing, no amount of power on a particular band will get you a contact, so the ability to move around the spectrum is very useful.

Since I acquired an FT817 I have only used that radio for activations. I must admit I was a little wary at first taking no more than 5 Watts up a hill, but with the added confidence that if I had to use CW, I could, I have found it to be very rewarding, & somewhat easier to carry. HI!

I have activated the same summit twice this year, with the same radio under both very poor HF conditions,(G/SP-012 22nd May 2010) & under absolutely superb HF conditions, (G/SP-012 24th September 2010). In May I only managed one contact on HF with the other 21 contacts being on VHF. HF conditions were not very good at all that day & 22 contacts was my total for several hours on the summit. I as not complaining though, as the weather was glorious :slight_smile:

On 24th September with much better conditions on HF, I managed 48 HF qso’s in 59 minutes, with a final 2 qso’s on 2 metres FM using a handheld. HF conditions that day were superb with both 60m & 40 in fine shape.

I had found a 7Ah slab to be quite a bit more capacity than I would need for the FT817, so I took a 2.2Ah slab which still had plenty of life left in it when I got home.

Your 7Ah Slab should be more than sufficient for a single summit activation with your FT857, but for more time, you will need to drop the TX power down to only what is necessary.

More activators do seem to be looking at Li-Po batteries due to their smaller size & higher capacity. As mentioned, these have been discussed in great detail on the reflector, & I am sure that a search of past topics would be very informative.

With regard to the 7Ah Slab’s durability in a rucksack. Apart from accidentally shorting the terminals, you should not have any problems. Most Slabs used by activators have a gel type electrolyte, which should not leak, although the battery will vent any excess gas it may produce.

Best of luck with your future activations, & don’t be afraid to experiment :slight_smile:

Best 73,

Mark G0VOF


Hi Tony,

Having made the change from 817 to 857 as I have done, I think you’ll appreciate operating the rig in colder weather when the larger controls are easier to handle than those on the 817.

Just a few suggestions:

  1. Lighten your load by carrying 4 cell LiPOs (with diode dropper) rather than a 7AH SLAB or build a LiPO / NiMH combination like I use which is suitable for both the 817 and 857 and weighs just 480g (http://www.flickr.com/photos/18897403@N00/4491202158/) There’s plenty of advice elsewhere on the reflector.

  2. Packaging of the rig - the rig has a fan for cooling, so I’ve mounted mine in a lightweight plastic box which allows me to leave it in the backpack and still operate if it is wet (http://www.flickr.com/photos/18897403@N00/4860147246/) I use polystyrene wrapped in Jumbo tape to wedge the rig firmly inside the box and the box is bound with simple webbing straps. I’ve brought the various connections out to the front to avoid having to access the back of the rig.

  3. Generally try to determine band conditions and use the minimum power to achieve a steady run of contacts, raising the power at the end of the activation to pick up those having difficulty with your signal. I rarely use more than 30W on HF.

73, Gerald G4OIG


In reply to M0ZZA:

I admire all of you who even consider hauling these rigs and batteries up a hill, the pack weights must be enormous. My last activation (WS-157) nearly crippled me and I was just carrying the 817 and a Lithium Ion battery pack plus food and lots of water.

The thought of backpacking an additional 10Kg up an unrelenting 45 degree, rough heather hillside gives me nightmares! Then, I am getting old!

Barry GM4TOE


In reply to G4OIG:

build a LiPO / NiMH combination like I use

Could you explain this a bit more please.

btw - I agree with you on power needed. These days I use my Clansman PRC 320 for HF on SOTA, yes it’s pretty heavy but it’s a self contained complete system already packaged as a backpack.



In reply to G8TMV:

build a LiPO / NiMH combination like I use

Search the reflector for previous posts about this Colin. It’s all there preserved in its glory for everyone to use.



In reply to G8TMV and GM4TOE:


Email me (as QRZ.com) if you need more info than is on the Reflector.


Nowadays (after a weight reduction exercise) my backpack is normally 12.5kg, but in that I have retained a decent first aid kit, 2 man bothy bag, plastic tarp, etc… after all, I never know when my reputation for soliciting dire weather conditions is going to be enhanced :wink:

73, Gerald G4OIG


In reply to GM4TOE:
Hi Barry,
I understand your reservations about increasing your pack weight when ascending the ‘real’ mountains of north Scotland but I’m not sure your weighing scales are the same as those south of the Border. The FT-857 only adds 1KG, including LIPO batteries to the 817 pack weight, which I can live with. It’s horses for courses, really, and if one’s interests tend towards QRP, then the 817 is ideal. On balance,I prefer the 857, as working country wide on VHF/UHF does it for me.
I’m getting old too! With the big 70 looming I’m starting a campaign to have the mountains brought to me. Would you care to subscribe?
73, Frank


In reply to M0ZZA:
Not sure what sort of current the FT857 takes. I run my Elecraft K2 at 5W off a 4AH gel cell and that is adequate for 6-8 hours of operation - the K2 will work adequately down to around 10V as all but the PA and audio stages are run off a sub 8V rail. So no need to carry more than a single battery… On my (rare) activations I have found 5W to be perfectly adequate on CW, although the 90ft top doublet helps a lot. On SSB you probably need a bit more umphh.

73 Dave G3YMC


In reply to GM4TOE:

I did an Activation of Pen-Y-Fan in July and felt shattered when I got to the summit. Then wondered about the weight of my bag. Checked it when I got home and it was over 15Kg - without the essentials. I’ve been adopting a slightly more minimalist approach since then!

I like the idea of the LiPO/NiMH hybrids, Must look into this further,