Posted by
Gary Smith-2 on
Oct 21, 2018; 10:18pm
URL: http://elecraft.85.s1.nabble.com/K3EXREF-issue-K3-tp7645822p7645856.html
Ed,
Thanks for the reply. I do need an
oscilloscope. The only frequency counter
at this QTH is this K3, my K3s is at the
factory for an issue with SSB.
That said, there does appear to be a 10MHz
signal coming from the GPSDO. There's
enough bleed-through that when I tune to
10MHz I can still pick up the ticks from
WWV, however removing power from the GPSDO
and the signal drops considerably. I
connected 10' of wire to the center
conductor of the SMA and the signal in the
K3 increased considerably and it was dead
on top of WWV. So I'm feeling it's putting
out a signal at 10MHV but the strength or
condition of the signal, I have no way to
tell.
Looking at the info on the K3EXREF, the
Tech MD is on, REF CAL is displayed and I
need to engage keypad #2 to switch between
the EXREF being in or out, I have it
switched in. No asterisk.
I have not been inside the radio since I
started using it a week ago and the
asterisk was flashing at that time. I
saved the current configuration and loaded
the configuration that was good the last
time I used the radio and that didn't
help. I can't imagine the cable in the
radio failed without any mechanical
action. I'll have to take a look and see
if anything has become somehow dislodged
though it's been just sitting on the
table.
I was hoping it was something in a setting
that might have been altered and it seems
like that's not it. Thanks again for the
assistance.
73,
Gary
KA1J
> Gary,
>
> Well first thing I would check is whether 10-MHz is present at the K3
> EXREF sma jack. If you have a freq counter check for correct freq.
> No counter then use a radio that can tune 10-MHz for presence of
> signal on correct freq.
>
> Check for adequate reference level (I run 10mw which is more than
> adequate; probably will run with 3mw to 5mw). If you have no
> milliwatt meter then use an oscilloscope to measure RF voltage. Pav =
> Vrms^2/R or Vrms = 0.3535*Vp-p*probe multiplier.
>
> From:
http://www.ab4oj.com/test/pwrmeas.html> Pav = 10*10^-3 = 0.01 w , Vrms = sqrt(Pav*R) = 0.707v, Vp-p =
> 2,.828*Vrms = 2v
>
> If you are using a 10x probe Vp-p = 0.2v; Be sure to measure voltage
> across 50-ohm load connected to the REF input.
>
> If this is low or nonexistent try a different cable from the
> GPSDO. Also check 10-MHz output at the GPSDO.
>
> My guess either you have no 10-MHz ref signal or its off
> frequency. If that is good then recheck configuration to enable
> EXREF. Still bad: then check internal coax from EXREF connector to
> syn board.
>
> 73, Ed - KL7UW
>
http://www.kl7uw.com> Dubus-NA Business mail:
>
[hidden email]
>
> ______________________________________________________________
> Elecraft mailing list
> Home:
http://mailman.qth.net/mailman/listinfo/elecraft> Help:
http://mailman.qth.net/mmfaq.htm> Post: mailto:
[hidden email]
>
> This list hosted by:
http://www.qsl.net> Please help support this email list:
http://www.qsl.net/donate.html> Message delivered to
[hidden email]
>
______________________________________________________________
Elecraft mailing list
Home:
http://mailman.qth.net/mailman/listinfo/elecraftHelp:
http://mailman.qth.net/mmfaq.htmPost: mailto:
[hidden email]
This list hosted by:
http://www.qsl.netPlease help support this email list:
http://www.qsl.net/donate.htmlMessage delivered to
[hidden email]