[Elecraft] New Output Power Issue

[Ian Kahn - Ham]

Don/all,

It is highly possible the culprit is my RigRunner, purchased in March of 
this year.  When I took it out of line, the voltage drop went from over 
4V on tx to under 2V (13.8V down to about 12V). Current draw is .78 to 
.82 amps on rx and 19.8 amps on tx. However, while the internal power 
meter shows 100W, an external meter into a dummy load only shows 70 
watts out.  The current and voltage readings look normal, according to 
Rev. D10 of the owner's manual.  But I'm still concerned about a 30W 
drop at the output. Anyone have any other suggestions?

Thanks, 73, es Merry Christmas.

--Ian

Ian Kahn, KM4IK
Roswell, GA  EM74ua
km4ik.ian at gmail.com
K3 #281, P3 #688
HRD v5.x/6.0 Test Team

On 12/24/2012 10:46 AM, Don Wilhelm wrote:
> Ian,
>
> With that much voltage drop, I would strongly recommend you look at 
> your power supply and the power cable to the K3.
>
> First measure the drop while transmitting right at the power supply.  
> If you have significant sag there, either your power supply is 
> marginal or the output terminals at its output may not be tight (on 
> most power supplies that means the inner nut is loose.  Also make sure 
> the cable is tightly clamped at the power supply end.
>
> At the K3 end, examine the APP connector.  Look into the end and make 
> sure the contact blade is fully latched over the spring finger.  If 
> the APP feels like it is not holding to the mating connector on the K3 
> with adequate pressure, then suspect incorrect assembly of one or the 
> other of the APP connectors (check the APP mounted on the K3 too).
>
> The conductors in the power cable should be of an adequate size to 
> carry the current.  US wire gauge #12 conductors or larger should be 
> used.  That is what is supplied by Elecraft.
>
> 73,
> Don W3FPR
>
> On 12/24/2012 10:18 AM, Ian Kahn - Ham wrote:
>> Update on my low output issue:
>>
>> I ran the TX Gain Calibration this morning, and everything passed 
>> with flying colors.
>>
>> I am seeing about a 4-4.5V drop across the radio when going from rx 
>> to tx.  Rx voltage sits at 13.8V, but when I transmit, voltage across 
>> the rig drops to between 9 and 9.5V.
>>
>> All tests performed while tuned into a 300W dummy load.
>>
>> Before I tear into my rig and start looking for corroded tin pins on 
>> the PA board (K3 #281, so unlikely the board was replaced/mod 
>> performed), is there anything else I should test while my station is 
>> still all together in one piece?
>>
>> Thanks to everyone for the assistance, and Merry Christmas!
>>
>> 73,
>>
>> --Ian
>>
>> Ian Kahn, KM4IK
>> Roswell, GA  EM74ua
>> km4ik.ian at gmail.com
>> K3 #281, P3 #688
>> HRD v5.x/6.0 Test Team
>>
>> On 12/23/2012 5:07 PM, Don Wilhelm wrote:
>>> Chuck,
>>>
>>> It could - defer decisions on that until after doing the TX Gain 
>>> Calibration.
>>>
>>> 73,
>>> Don W3FPR
>>>
>>> On 12/23/2012 5:01 PM, hawley, charles j jr wrote:
>>>> Could it be/affect a 40% difference?
>>>>
>>>> Chuck, KE9UW
>>>> Lionel Trains, TCA, LCCA, LRRC
>>>> aka Jack, BMW Motorcycles BMWMOA #224
>>>>
>>>
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>