[Elecraft] Calibrate TX Gain error

[Gregg W6IZT]

Good Morning:

 

I just ran the TX gain calibration and it fails on 29 MHz at both the 5 and
50 watt power levels indicating an SWR of 2.1:1. I checked the SWR manually
and indeed it is indicated at approximately 2:1 at 29 MHz. I manually
checked all bands and 24.9 MHz is indicating an SWR of 1.6:1. On all of the
other bands the SWR is 1:1 with the tuner in bypass. I am using a load good
up to 3 GHz. I have swept the load and the cable that I am using and the RL
is better than -40 dB throughout the HF and VHF spectrum.

 

It seems to me that all this points to the lowpass filter in the K3 for
12/10 meters. I can do a physical check for a bad cap or cold solder joint
and it looks like I can sweep the filter by opening W3 and sweeping into a
load connected to the antenna connector. Before I do this I wanted to
confirm if anyone else has seen this problem and if so, what was the root
cause?

 

Thanks in advance for your assistance.

 

73

Gregg

W6IZT