Re: Measured Low Voltage Drop Out? - General Comments
- --- In FT897@y..., "Woodrick, Ed" <Mail-Lists.FT-817@e...> wrote:
>You know, until I'd seen these threads on Low voltage Dropout and Min
> Rx Drop out is about 8 V
> Tx Drop out is about 9.2V the power starts rolling off.
> 15A full power Tx (SSB)
> 8A 20W Tx
> 4A 5W Tx
Rx Current Draw I thought I must be the only guy in the world who'd
taken an FT-847, IC-706 or an FT-100 in the field with a 7Ah gel cel!
Anyone like to tell me what the TX power is on 70cm with an external
11 or 12V is?
I was very disappointed when I read they the internal battery will
only allow 10W on 70cm. Not really enough for a decent AO-40 natter.
BTW had a nice long play with an FT-897 a few days ago at a hamfest
here in the UK and the radio is much bigger than I thought. Not much
smaller than the FT-847 which was parked next to it.
73 Howard G6LVB
- --- In FT897@y..., "Howard Long" <hlong@b...> wrote:
> You know, until I'd seen these threads on Low voltage Dropout and MinHFPack is an absurdly large group, now. You are not alone...
> Rx Current Draw I thought I must be the only guy in the world who'd
> taken an FT-847, IC-706 or an FT-100 in the field with a 7Ah gel cel!
BTW, current draw is also relevant for those of us looking at the
FT897 as a possible mobile rig -- power consumption does matter when
you need your car battery to start in a blizzard. There is no doubt
about it, the FT897 would be much kinder to the battery than an IC-706.
- Howard writes:
> You know, until I'd seen these threads on Low voltage Dropout andMin
> Rx Current Draw I thought I must be the only guy in the world who'dcel!
> taken an FT-847, IC-706 or an FT-100 in the field with a 7Ah gel
Nope, there are more of us than most realize. The FT-817 does seem to
dominate the discussion on many groups though. I had quite good luck
with a DX-70 and 7 & 17 Ah gel cells.
The Alinco would drop out starting at 11v or so, and that appears to
be a fairly common number for the mobile rigs. In examining the DX-70
schematics, it appears that the 8v regulator is the suspect.... it's
a common 7808. If I had kept the DX-70 I would have replaced it with
a low dropout version to see if I could improve the low voltage
But now that's not an issue, as I traded for an FT-897 yesterday. 24
hours observation: This is a very nice radio! Forget bells and
whistles, it has the features I have been looking for. Some are not
obvious, but show Yaesu was really thinking about it's intended use.
An example: The dial light is configued to stay on when connected to
external 12vdc, but goes into an auto mode when running off internal
batteries. Of course, this is configurable. This is a common sense
feature that was a nuisance when using mobile rigs. I was always
having to enable/disable the dial light for portable use.
There are many features that show the radio was well thought out for
small battery use. It also looks like Yaesu did well on the TX bias
issue everyone was concerned about. There has to be more to the
subject, as even the Alinco had lower TX idle current drain on 10w
than on 100. The 897 figures posted earlier are quite reasonable to
me given the DSP, etc. Definitely lower than using traditional HF
For what it is worth with 24 hours of ownership, unlike most rigs
I've owned, I have not found a "wish they had done XYZ" on the 897
yet. (beyond the obvious ones like price, battery capacity, etc)
Actually, there might be one. Though the rig is quite substantial,
far sturdier than most, I really wish it was weatherproof. I'm not
even that concerned about water as much as all the holes for dust,
dirt and mud to enter.
I also wish the AT was not coaxial, or at least had a top mounted
threaded mount for portable use like some of the military manpacks.
(And possibly the VX-12xx?)
> BTW had a nice long play with an FT-897 a few days ago at a hamfestmuch
> here in the UK and the radio is much bigger than I thought. Not
> smaller than the FT-847 which was parked next to it.It is larger than you think initially. Certainly larger than my DX-
70. But when you compare it to the size of a DX-70 and a 7AH Gell
cell, then it's quite reasonable. You have to remember that the stock
FT-897 is almost half empty with the slots for battery packs or
My issue with the separate radio/battery/tuner was the form factor.
They all made quite thick packages, and you had to pad them or use
some form of enclosure to keep from damaging them in portable ops.
The 897 form factor is close to ideal, as wide but thin is far easier
to backpack than thick but narrower. (They are all about the same
I'm curious to see if the battery connection uses any form of
standard connector which would allow the use of external batteries
while triggering the "battery" mode of the radio.
Also will have to give some thought on charging the NiMh batteries
with solar without the losses the charger provides. (IE: is there a
safe attended "trickle" charge for the NiMh without the controller)
OK, I'll report more later! But so far, I'm quite pleased.