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GM7HUD > FT817 12.12.06 02:01l 80 Lines 3570 Bytes #999 (0) @ WW
BID : 134187GM7HUD
Read: DL6DBA GUEST VE7HFY
Subj: Re: Using the empty battery ca
Path: DB0FHN<DB0RGB<DB0MRW<OK0PKL<DB0GRL<SR6BBA<SR1BSZ<TU5EX<VK4TRS<VK6HGR<
GB7ESX
Sent: 061211/1601z 44405@GB7ESX.#31.GBR.EU $:134187GM7HUD [Witham, Esx]NNA V3.1
G0FTD wrote:-
>
> The difference between the FT817 and the ND are staggering (not).
>
> The ND gives you a 1300ma pack instead of 1000ma as well as 3 colours for
> the display instead of two. I heard a rumour that the PA stage is different
> and the radio will cover as standard the Alaskan 5Mhz channel without
> doing a full broadband mod.
>
Oh, I thought it had the DSP as well. My 1000mA battery pack is still
sealed. It's always been run on the NiMHs. I bought it secondhand like
that.
It was already opened up and had the old 5MHz frequencies in the memories.
> Have you noticed that on 2m the SWR indicator appears to be a bit gay,
> showing 2 or 3 bars even with a reasonable match ?
Funny you should mention that. My HB9CV gave a horrible reading on the
inbuilt SWR meter when up the hills at the weekend. But it was full scale
badness, so I used the rubber duck. When I got back to the shack and
inspected it, I was expecting the cable to be broken somewhere but it was
FB. Nothing I could do would produce an acceptable match till I noticed the
bolt which connects the phasing wire to the elements was missing. Must have
fallen out when the antenna was being humped about. A new bolt restored
operation and it'll get glued in place so it cant go walkabout again. But
the 817 reading is higher than the external SWR meter.
The old PAs are meant to be rather more fragile and don't like bad
mismatches. Which is why I was concerned to get the antenna fixed. My old
FT470 handie would give "full poundage" (got to use these M3 terms since
the new BR68 came into force) into anything from short to open circuit
without complaint. The later sets have different PA devices which are more
resilient.
> I have here 2600ma cells, so that would be two rounds of 10hrs.
Coo! That's almost as much as my 1.18kg SLA. (HUD Makes silent but amazed
looking facial expression.) But the SLA is 12V and so would be 5W on high
power as opposed to 2.5W from the internal pack.
> What worries me is can the charger circuitry provide enough initial current
> for the larger cells without some on board regulator getting a permanent
> headache.
>
It'll happily charge the 1300mAHr pack. It doesn't know your pack has a
higher capacity and it stops charging on time not terminal voltage. So
there should be no issue with hit charge again after 10hrs. The only
problem being 20hrs at least to charge the cells. An external charger makes
sense as a C/10 rate charger at 260mA will charge them in 14hrs. A big
problem with high capacity packs is that fast charging them requires beefy
chargers. A 4C charger would need to be able to supply a constant current
of 10.4A. Yow!
>
>> Of course the lower temperature on the tops of mountains wont help.
>
> I can certainly conferm that the colder it gets, the less current available.
>
I need to keep the batteries warm when climbing. I was thinking about
asking the memsahib to sew a pocket into my underpants so I could keep the
cells warm. But I thought the funny looks you would get when you put your
hand down the front of your pants and pull out AA cell after AA cell may
meet with disapproval! :-)
> I seem to recall that Lithium Ion where mentioned on the Southgate ARC
> website recently.
I've found someone selling an 11.1V 4Ahr pack for $44 in California. $26
for the charger that will charge them in 2.5hours. Shame the postage to the
UK is more than the cells and charger. But interesting as that LiIon pack
has just under twice the capacity of my SLA and weighs 280g instead 1.18kg.
73 de Andy GM7HUD
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