Using a DVM or other self-contained voltmeter, measure the voltage at
the power supply end of the cable during Rx and Tx. Is the voltage drop
small (under 1/2 volt)?
Measure the voltage at the radio end of the cable (using the same
voltmeter) during Tx and Rx. Compare it to the K3 voltmeter. The
difference between the two voltages should be almost constant, with
perhaps a couple tenths of a volt greater difference when in Tx. Is the
excessive voltage drop occuring across the cable? Might it be poorly or
improperly mated Anderson power-pole connections? Or loose connections
at the power supply? Are you using a power distribution box like a
RigRunner? Is the drop occuring there?
The most common cause of this sort of problem is the cabling --
including connectors -- between the power supply and the radio.
73,
Lyle KK7P
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....@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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