[Elecraft] K3 output power failure.

[Eric Rosenberg]

W3LPL and other mentioned the PA temp and sagging power supply.

I didn't think to check the PA temp  until later (how much later, I don't
know),  If I remember correctly, it was 35C. In both cases, I was operating
in a contest (ARRL 160 and ARRL RTTY RU) with the RF power set to 100w

Sitting in front of the rig now (been powered for 15 or so minutes), the PA
is 26C.What did catch my eye was the voltage and current at the rig: 13.3v
& 1.2a in RX

I then keyed the radio, brought the power to 100w, it's a the voltage went
to 11.8v/17.9a and then shut down. The voltage went up to 13.3v/1.2a but
still no output. PA temp is 31C

I swapped power the Astron power supply for an Alinco DM-330MV switching
supply (1 ft power cable to the radio). I set the power supply so the radio
reads 14.5v. I also turned up the fan up to level 4 (it hadn't gone on
previously).. The radio read 14.5v/1.3A on RX. PA temp 22C, FP temp 30C in
RX

Still no TX output, although the radio went to 14.2v and 2.3a when I first
keyed the radio. It quickly ramps up to ~4.a and stays there until I unkey
it.

Any ideas as to what's going on?

73, Eric W3DQ




On Mon, Jan 6, 2020 at 9:29 AM Bob McGraw K4TAX <rmcgraw at blomand.net> wrote:

> What was the PA temperature?   And how are the fans set in the CONFIG
> menu.
>
> Bob, K4TAX
>
>
> Sent from my iPhone
>
> > On Jan 6, 2020, at 12:15 AM, Eric Rosenberg <ericrosenberg.dc at gmail.com>
> wrote:
> >
> > In the middle of the ARRL 160 contest, my K3 stopped putting out any
> RF. No  explanation that I can think of... all of a sudden, ZERO watts out
> when the radio was keyed, either by software (N1MM+ or WSJT-X) or pressing
> the TUNE button. The TX LED was lit, the meter showed audio, which I could
> hear via the radio MON.
> >
> > I could not get it to come back. I shut it off for a couple of minutes
> and then it came back.
> >
> > Everything seemed fine until this weekend's ARRL RTTY Roundup. After
> being on the air for about 4 hours, once again there no was RF output (the
> meter said "0 watts with two dashed lines above it), The radio keyed (the
> TX LED went on and the meter showed audio which could be heard via the
> radio MON), and the meter said "0 watts with two dashed lines above it.  I
> disconnected everything but the antenna, and still... no change. I did a
> system reset. Again, no change.
> >
> > I quit for he evening and came back in the morning, On a lark, I hooked
> it all back up, and lo and behold, everything worked as if nothing had gone
> wrong.
> >
> > I'm stumped. I've never opened up the radio -- the only time it was
> opened was at Elecraft last year.
> >
> > Any advice is appreciated!
> >
> > 73,
> > Eric W3DQ
> >
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