K2 - High Current & Low Battery on 20m only

[konigsburg]

I have K2/100 #3132 with the 160m, SSB, and DSP modules installed. I am
also using a KAT100. I have had this set up for a couple of years. The
power source is a battery that is being charged as I am operating. My
antenna is a Zirpel (like a Carolina Windom). The KAT100 is able to find
a match on all bands.

On 160m, 80m 40m, 15m, and 10m all is fine (I don't operate that much on
30m, 17m, and 12m). However, on 20m I usually get a "High Cur" warning
when I first operate (CW or SSB) on that band. Then it goes away. All
seems to be operating OK. Sometimes, a bit later when operating on 20m,
I get a "Low Batt" indicator. That too goes away and all seems to still
be operating OK. I have a voltmeter attached to the battery and when the
K2 gives the "Low Batt" warning, the voltmeter says 13.2 volts. I have
not seen any of these symptoms on any other band.

I am using a home brewed battery charger that my elmer made and it keeps
the battery at 13.6V.

The problem typically occurs when operating on 20m after I have turned
on the rig. It rarely happens when the rig is a bit warm. So a warm rig
and the problem usually does not occur could indicate a bad solder
joint? I am not much of an EE so I would appreciate advice on how to
track this one down. The Cal Cur is set to 3.7.

Thanks

73,

:) PK (Paul - K3MZ   K2 #3135  K3 #xxx)


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[Don Wilhelm-3]

Paul,

I believe you may have 2 problems.

The LO BAT indication - check the jumper or switch on the control board
just to the right of center - if it is a switch, be certain it is
positioned to the left (INT) position, but if you have a post-SN3000 K2,
the switch has been replaced with a jumper/header, and thejumper should
be in the INT position (to the left IIRC).

For the HI CUR indication on 20 meters, first check to be certain you
have the K2 bandpass filter aligned correctly for a peak (do this
adjustment at 2 watts).
If you found no problem with the bandpass filter alignment, then look at
KPA100 R19 and R20.  If the resistors have blue bodies, they are
possibly inductive (the non-inductive resistors have a reddish brown
body).  Should you have the inductive variety, request replacement
resistors from [hidden email].

73,
Don W3FPR


Paul K wrote:

> I have K2/100 #3132 with the 160m, SSB, and DSP modules installed. I am
> also using a KAT100. I have had this set up for a couple of years. The
> power source is a battery that is being charged as I am operating. My
> antenna is a Zirpel (like a Carolina Windom). The KAT100 is able to find
> a match on all bands.
>
> On 160m, 80m 40m, 15m, and 10m all is fine (I don't operate that much on
> 30m, 17m, and 12m). However, on 20m I usually get a "High Cur" warning
> when I first operate (CW or SSB) on that band. Then it goes away. All
> seems to be operating OK. Sometimes, a bit later when operating on 20m,
> I get a "Low Batt" indicator. That too goes away and all seems to still
> be operating OK. I have a voltmeter attached to the battery and when the
> K2 gives the "Low Batt" warning, the voltmeter says 13.2 volts. I have
> not seen any of these symptoms on any other band.
>

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