[Elecraft] HI Current

[Bruce Chadbourne]

Don, et. al.
Thanks for the replies. I can repeat this problem (a good thing) at 20m CW
around 14.115 Mhz.
Power supply (Astron VS-35M, front panel meters) showing proper voltage,
and current knob set toward max.
At 14.050, SWR reads 1.0 on the K3. Power set at 100w. Voltage reads 13.8v,
then with key down, K3 meter says 23 amps, voltage drops to 12.6v    No HI
CUR warning.

At 14.115, SWR still 1.0, 100 watts,  13.8v, put the key down, the HI CUR
warning appears most of the time (so I can't read voltage/amp on K3 meter).
One time it didn't show, and current was still 23-ish amps, and voltage
12.6; at which point I realized the rig had automatically reduced power
from 100 to 88 watts.   The ammeter on the Power supply reads about 17 amps
at both freqs, with and without HI CUR warning.  The power supply voltage
meter does not show the deflection below 13v, stays rock steady. That seems
to say the voltage drop under load is happening at the terminals or power
cord

Per your suggestion I checked the lugs on the back of the power supply -
very firm, but I guess  I'll disconnect the leads and clean them and repeat
the test.
I guess my question to the experts in the group: does a 1.2 volt drop at
the rig sound normal at 100w? I am using the power lead that came with the
K3 kit; it looks healthy, hasn't been out of the shack on any field day ops


On Mon, Dec 15, 2014 at 4:20 PM, Don Wilhelm <w3fpr at embarqmail.com> wrote:
>
> Bruce,
>
> I would expect a Hi REFL message rather than Hi Cur if SWR was the problem.
> Check your power supply connections.  If you have bolts and nuts on the
> power supply output terminals, if the bolts turn (even slightly) when you
> tighten the nuts, you will have to dig inside the power supply to fully
> tighten the bolts to the lugs on the inside.
>
> With Elecraft gear, a low power supply voltage will result in a higher
> current draw from the power supply.  Elecraft gear seeks to maintain the
> requested power output, and a low supply voltage means that the current
> must increase to maintain the power level.
>
> 73,
> Don W3FPR
>
>
> On 12/14/2014 4:18 PM, Bruce Chadbourne wrote:
>
>> To the list:
>>
>> I occasionally get the Hi Current warning on my K3. I notice it cuts my
>> power back about 10% from 100w.  My initial assumption is that my SWR is
>> too high - but the SWR meter is easily less than 2.0  I run the ATU which
>> confirms SWR about 1.2 or so.
>> So what am I missing - something bad in my transmission line?
>>
>>
>

-- 
Bruce Chadbourne PgMP
1034 W Beagle Run Loop
Hernando, FL 34442
352-453-5456

If urgent, the best way to reach me is by phone. Thank you.