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Re: HHB Portadisc

Subject: Re: HHB Portadisc
From: Walter Knapp <>
Date: Thu, 04 Sep 2003 17:16:29 -0400
Marty Michener wrote:
> At 03:13 PM 9/4/2003 -0400, Walt wrote:
>>The numbers are a measure of voltage of the pac. They are pretty
>>accurate if you are using a set of alkalines, which drop fairly steadily
>>in voltage. Unfortunately NIMH don't drop much for the first 80% of the
>>discharge. I start thinking replacing the pac when it's got down to 97%.
>>And as I said will not go below 70% unless in the middle of a really
>>valuable recording. Typically I replace the pac early so I won't get
>>caught like that.
>> From my measurement of the Portadisc's current draw, it's not hard to
>>see how the voltage is going to vary. With the full recording load I
>>occasionally saw lows close to 200ma. There was far more variability in
>>the load than I expected.
> Yes, Walt, that explains why the numbers jump all over.  But mine are
> frequently well below 70% for much of a recording, and get to 40 or 50%
> before I need to switch.  I gotta check this and take notes (oh great, on=
> more "experiment" needed for the equipment sake, ( ;^) ).

I'd not be too surprised at that with the fuji set. The ones I got are
very erratic. I've only got 4 of them left, and even hate to put them in
a headlamp. Though fully charged I've had all 4 cells die in minutes,
then next charge be normal. Really annoying if you are standing in the
middle of a swamp, change batteries and just go a few steps...

But, with the GP batteries, or Kodak, or Sanyo, all of which I've used
at some time, I have never seen such erratic readings. Nice and steady.

I expect that several parts of the Portadisc are on pulsed power to save
energy. And that more than one cycle is involved.

If neither your Radio Shack or the Fuji are stable, it might be time to
try a new set.

I am really curious at the wildly changing readings. So out of tune with
what I see.

> Maybe I'm a klutz, but I always have my hands and brain full making
> half-way decent recordings, being stealthy and ID'ing my vocalizing
> victims, without studying the erratic course of a bunch of numbers that
> seem to follow almost no pattern, then plunge!

I've somehow got some part of mine trained to zero in on the reading
when it drops. I'm almost always recording with a steady 99% indication.
So I only have to latch onto some other pattern. Since I'm keeping a eye
on that audio level meter some of the time it's pretty well taken care
of without thinking. And I change early, don't try and suck the
batteries dry. After all there are enough chargers in the Ranger to
charge faster than I use. And a bag full of already charged batteries I
could use. I'm a believer in having excess batteries.

> I certainly agree one shouldn't design a fast heat-producing charger into=

> the recorder, and I am grateful for your suggestions on the Maha MH-C401F=
> chargers!  Gotta try'n git me one or two.

They are not cheap. I'm still examining what they can do. I only bought
two. I usually have plenty of time and generally charge the Portadisc's
batteries in the Portadisc and use the chargers to charge headlamp
batteries and so on.

I just checked the place where I got mine. Now claiming 100 minutes
instead of their earlier emphasis on a hour. Probably more accurate for
high cap batteries. Here's the link:

As I noted, there are bound to be other brands. Though the pulse stuff
is pretty new.

I stuck a couple GP 1800 mAh batteries on the discharge cycle on the
other chargers. When it indicates fully discharged I'll try and remember
to time fast charging in the pulse charger for you. I don't use the fast
charge all that much. Still runs against my previous battery experience,
but is probably perfectly ok. Theory sounds real good.



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