[Elecraft] Help with High Current issues

[Guy Olinger K2AV]

An HPS-1a with the K3 on CW is a stretch. The HPS-1a only works well with
100w with fairly limited duty cycle transmissions and even then doing
tune-ups needs to be at about 20 watts or so. I was really interested in
the HPS-1a idea some years back for portable use, but had to give it up.
There were some number of verbal rebuffs on the idea among the experienced
at Potomac Valley Radio Club meetings (contesters). This goes along with
negative (for contest use) reviews at EHam at
http://www.eham.net/reviews/detail/5784  Among other things, they reported
that DXpeditions, with their tireless duty cycle, burned up HPS-1a's.

To be robust, a K3 should be powered by a power supply capable of 30 amps
continuous without sagging. Running on the cheep has various problems
around the edges. You can use an HPS situationally, but don't look for
anything beyond its true limits. Running compression will increase the
current draw. The additional power is the point of compression. CW CQ's
running with interspersed QSO's need to be planned with a 40% to 50% duty
cycle.

My RV with it's 65 amp inverter supplying the 13.8 volt DC battery rails is
just good enough to additionally supply a pair of K3's direct from 13.8 DC
rails in a CW field day setting without running down the batteries. The
batteries are a pair of huge T105 6 volt golf cart batteries in series. A
pair of K3's running draw way more than lights and other miscellaneous DC
supplied devices on the RV's DC circuits. Makes the lights blink a little.

73, Guy K2AV

On Sun, Jan 11, 2015 at 5:29 PM, alan geller via Elecraft <
elecraft at mailman.qth.net> wrote:

> Well, as soon as I sent my SOS, I realized I was telling all, I was too
> lazy to switch to a beefier power supply to figure that out. Our course,
> your suggestion solved that issue so I am getting double slow on the neuron
> pathways.The voltage went from 13.5 V to 9.5V on the 6th (set for 20WPM)
> dash and shutdown is around 9.2 V.Soo, my conclusion has to be that the
> SuperCaps in my trusty small/expensive power supply are getting tired.I
> just this minute read a review of the HPS by Phil Salas – AD5X, and he got
> a 2V drop at 10 WPM, so my unit seems to be out of spec and that is a
> "different" issue for this generally useful product.Thank you all for your
> quick response.......Happy 2015
> Alan....K6ADG
>
>
>      On Sunday, January 11, 2015 10:45 AM, James Bennett <w6jhb at me.com>
> wrote:
>
>
>
>  What is your K3 showing as the voltage when you change the DISP to read
> that instead of VFO-B frequency? Low voltage would cause the current to
> increase to keep the power where you set it.
>
> > On  Sunday, Jan 11, 2015, at  Sunday, 10:30 AM, alan geller via Elecraft
> <elecraft at mailman.qth.net> wrote:
> >
> > What is causing my my seemingly odd occurrence of a low SWR and a high
> current shutdown on my K3 ? It just happened this morning and is very
> worrisome.
> > Freq:  14.055SWR:  1.3:1Antenna:  OCF dipoleSending Dits: Random Hi Curr
> warning for 45 sec and then a shutdownSending Dahs: Random Hi Curr warning
> for 10 sec and then a shutdownPower Supply: Gamma HPS-1aOther indications:
> dimming of backlight synched with XMIT approx 5 sec prior to shutdown
> > Thanks for any help...this is a new issue
> > Alan....K6ADG
>
>
>
>
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