FT-857D Portable Help

In reply to G3RMD:

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

Three score and ten lands on my shoulders in January. I like the idea of that campaign, but we are thinking of moving either to the Welsh Borders or Eden Valley next year…Mohammed going to the mountain!

Enough of that! Now I have both the 817 and 857 available, I can say from experience that dropping those few pounds and taking the 817 up a hill feels like losing 10 years of progressive enfeeblement! My intention now is to only take the 817 on the higher hills and save the 857 for the 1 and 2 pointers. The alternative is to put panniers on the dog - goats aren’t too easy to keep in a city garden!

73

Brian G8ADD

In reply to G8ADD:

I partially solved the problem of the bag I carry being too heavy by reducing my own weight by 8.5kg. Well actually it’s a result of the new diabetes drugs, effortless weight loss! Means I can have a few more drams without worrying about the waistline anymore! :wink:

(the new slimmer) Andy
MM0FMF

In reply to G8TMV:

RT320. I’ve two of these gathering dust at the moment. Great radios. I wonder whether the 24v NiCADs could be replaced or refurbished with LiPO cells.

73

Tony

In reply to M0ZZA:

RT320. I’ve two of these gathering dust at the moment. Great radios.
I wonder whether the 24v NiCADs could be replaced or refurbished with
LiPO cells.

They are becoming quite popular and much sought after at sensible prices on Ebay (rather than the several hundred quid some people are trying to sell them for). There is now a very simple pll based LSB mod for them that makes them much more useful since they can be used on 40m and 80m. The batteries seem to be very good quality. The three that I got with my 320 had been sat on a pallet in a shed for 5 years. I put them on a bench supply in constant current mode at 100mA for several days then cycled them normally. All three seem to be in good condition.

Colin G8TMV

Well I’ve finally received my 4 cell LiPo batteries from Hong Kong. Took just over a month to arrive. The charger only took 5 days. So will get batteries charged up and give everything a whirl on Pen-y-Fan before Christmas. I’ve made a voltage dropper as well.

I’ve searched the reflector for around an hour but can’t find where I read it so apologies if this is elsewhere on the reflector. The LiPos are 14.8v 4 cell units 5000mah 20C with a 30C burst. I read somewhere (probably not on the reflector) that to get an accurate battery capacity I should multiply the mah by the C rating giving each battery 5000x20=100,000mah(!) 100ah? If I run them in parallel that would be 200ah? That seems a lot to me!? What does the 30C burst mean in this case?

Tony
(ignorance was bliss!)

In reply to M0ZZA:

was it this site

Phil G4egu

In reply to M0ZZA:

5000mAh is the capacity. You’d think you could draw 5000mA for 1hr or 2500mA for 2hrs etc. with such a rating but you’d be wrong. This is normally the 20hr rating. i.e. you can draw 250mA continuously for 20hrs. But when you draw more the life drops faster.

20C/30C is the peak current rating. i.e. you can pull 20*5000mA or 100A for short periods and 150A for very short periods. This is of interest to RC modelers as their motors pull high currents. So they may get 10-15mins flying time out of such a cell. 5000mAh will run an FT817 on SSB for many hours.

Of course these are from BV-land so specifications are not robust. In fact they’re probably outright lies. Take them with an industrial size pinch of salt! :wink:

Andy
MM0FMF

In reply to G4EGU:

Not that site, however far better information here than I have read elsewhere thanks. Just need to construct a fire proof charging box. No doubt that will provoke comment from the XYL.

Where are those asbestos tiles…

:wink:

Tony

In reply to G4EGU:

Not that site, however far better information here than I have read elsewhere thanks. Just need to construct a fire proof charging box. No doubt that will provoke comment from the XYL.

Where are those asbestos tiles…

:wink:

Tony

In reply to M0ZZA:

Just need to construct a fire proof charging box.

No need - charge them outside if you can. I use an old car battery to charge mine up. If it looks like rain, I throw a polythene sheet over the lot. In fact (gasp, horror, shudder), I’ve taken to charging them inside in the Utility… and unsupervised as well. I know how to live dangerously!

Seriously, don’t take any notice of those YouTube videos where idiots short out LiPos to get their kicks. Apply commonsense, be careful with the charging connections (the leads are not particularly robust) and you should be okay. After all, were you intending carrying your fire proof box up the hills?

73, Gerald G4OIG

Haha, Just found Tesco are selling some 10.2 Netbook cases with rigid sides and red zip. Well padded and a nice soft interior. The 857 fits very snuggly in it. Perfect fit,

Tony

In reply to M0ZZA:
Another possibility (just for pure padding) is the soft laptop/netbook cases that the Poundshop sells. They do ones for 10.2" (might fit an 817) and a 12.5" which would probably fit an 857. Obviously they aren’t waterproof, but for a bit of extra padding in a rucksack…

Jonathan
M6HBS