[Elecraft] New Output Power Issue

[Don Wilhelm]

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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