[SJDXA] [GCARC] Elecraft K4 problem

[Ben Johnson]

The strange bugs never stop coming, which serve to keep the gray matter
gray and keep us humble.

Glad you found your problem, Bob.

Have a nice weekend.


On Thu, Oct 30, 2025, 17:06 Robert Pantazes <robert.pantazes at gmail.com>
wrote:

> I started the CQ WW Phone contest and the 3rd contact told me that my
> Transmit audio is breaking up.I switched to a dummy load and started to
> monitor my TX audio with a headset, sure enough it was breaking up. I
> plugged in the Heil Headset microphone to the same jack on the rear of the
> K4 and had the same problem. I cleaned out the jack on the K4 with contact
> cleaner and that was not the problem.
> I built an adapter for the front jack (8 pin round connector) and plugged
> the mic into the front jack, the problem cleared up. I went back to the
> contest but I was bothered by this problem.
> On Monday I plugged into the rear jack and monitored the break up. If I
> turn off the preamp the break up stops. I emailed Elecraft and explained my
> situation. Doug at Elecraft answered me and asked for a recording of the
> problem, so I emailed a MP3 file. Later that day I received an email to
> check for RF leakage. I was transmitting with only 5 watts and did not see
> RF on the field strength meter.
> The K4 has menus to monitor voltages, I noticed that on TX the input
> voltage drops to 10 volts. A BAD power supply! I changed the power supply
> and had 13.7 volts at full power and the TX audio sounded great. Why this
> happens only on the rear mic input is a mystery for Elecraft to figure out.
> I did let Doug know my solution and he thanked me.
> That's how I spent my Monday after CQ WW.
> One last thought the bad power supply maker will go nameless but they have
> 3 letters in their name and are out of business from Starkville MS.
> 73,
> Robert "Bob" Pantazes, W2ARP
>
> --
> A. Robert Pantazes, SBE CBT, Retired Broadcast Engineer from Broadcast
> Science.
> E-mail address is W2ARP at arrl.net or robert.pantazes at gmail.com
> Our new address as of March 1, 2024 is,
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