Login  Register

Re: Tone/"Low Bat" indication?

Posted by S Sacco on Apr 05, 2009; 2:54am
URL: http://elecraft.85.s1.nabble.com/Tone-Low-Bat-indication-tp2586773p2587368.html

Hi Dave -

OK, sorry for the misunderstanding; I thought you were talking about the
K3's internal battery.

Now that we have that out of the way:

1) "BAT MIN" is set to 11.0 v

2) When I measured the voltage using the K3's internal metering:
    a) It was 13.6 v at receive
    b) It was 10.8 v while transmitting 95 watts output  **** Clearly, 10.8
< "BAT MIN" ****

3) I measured disconnected and reconnected the Anderson Power Pole connector
at the back of the K3, and the voltage increased to 10.9.

4) I have the power from the power supply (an Alinco DM-330MV) running to a
set of fuses before continuing on to the K3.   It's one of those gold-plated
dressy looking deals that car audio folks use to bling-out their
installation (I got them cheap at Skycraft Surplus here in Orlando about 10
years ago).
   a) I removed both fuses (one for +, one for - ) and treated both the fuse
and the holder with DeoxIT.
   b) At the same time, I treated the PowerPole with DeoxIT.
   c) I also noted the the - lug on the back of the Alinco was slightly
loose, so I tightened it.
   d) My apologies for not doing one thing at a time, and then measuring the
result; that would have been the proper procedure.
   e) Upon the above treatment and actions:
        i) The voltage rose to 13.7 v at receive
        ii) The voltage rose to 11.4 v while transmitting 95 watts
        iii) To add another datapoint, I reduced the power to 45 watts
(typical power when driving my amp) and the voltage was 12.0 v.

Conclusion: Voltage drop due to I squared R losses.

I didn't measure the voltage on both side of the fuses before the DeoxIT
treatment, which was another mistake in my diagnostic approach.  I did so
after the treatment, and noted a voltage drop of only .1 volt (from 12.9 to
12.8) across the fuses while under load.

Thanks for the tip Dave; it was much appreciated!

I've Cced the reflector, and hope this serves as a good example for everyone
to mind their connections.

73,
Steve
NN4X



On Sat, Apr 4, 2009 at 8:56 PM, David Gilbert <[hidden email]>wrote:

>
>
> The age of the battery doesn't mean much, and if it is weak it will be
> while you're transmitting that the voltage will sag.  To check it, all you
> need to do is tap the DISP button, and then spin the VFO B knob to monitor
> the battery voltage right on the K3.  If it falls below the value set for
> BAT MIN in the CONFIG menu, you're going to get a warning ... and probably a
> glitch if the warning happens while you're sending.
>
> Dave  AB7E
>
>
>
> S Sacco wrote:
>
> David -
>
> Given that my K3 is about 9 months old (thus, the battery is pretty fresh,
> no doubt), and that it happens irregularly and momentarily, while
> transmitting, leads me to suspect this is not a "low battery" condition.
> Given that, I have not checked the battery.
>
> 73,
> Steve
> NN4X
>
>
> On Sat, Apr 4, 2009 at 7:57 PM, David Gilbert <[hidden email]>wrote:
>
>>
>> Have you checked the actual battery voltage that you're using?  It seems
>> to me that the K3 is trying to tell you something.
>>
>> Dave   AB7E
>>
>>
>> S Sacco wrote:
>>
>> I was working a station on 40M CW (qsk) this afternoon, and suddenly - and
>> only for a moment, my K3 got stuck and put a high pitched tone into the
>> speaker, while at the same time, indication "Low Bat" (perhaps "Low
>> Batt"?).  It then returned to normal operation.
>>
>> I've experienced this "getting stuck" thing a few times, but never looked at
>> the display while it was happening.
>>
>> I'm running 3.04 right now.
>>
>> Has anyone seen this behavior?  If so, is there a way to address it?
>>
>> Thank you & 73,
>>
>> Steve
>> NN4X
>> EL98jh
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email] <[hidden email]>
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>>
>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html