Tom,
welcome to the club. I think anyone who has put together a K2 has such
stories. In my case I had installed U4 backwards and did not notice it
as the chip has a very pronounced 'dimple' on one end which (for some
reason) made me overlook the notch on the other end. I spent a week
trying to figure out the problem poring over the troubleshooting steps,
emails to Don, and magnified visual checks against the part location
diagrams. I never did see that error and sent the rig to Elecraft,
where it was noticed and replaced.
73,
Neil, KN3ILZ
On 1/22/2019 9:57 PM, K2bew wrote:
Don Et Al,
So, It is with some embarrassment, and much relief, that I can report it
was operator error and my BFO is now working perfectly.
I got home from work and was getting ready to do some continuity checks to
all the circuits surrounding and including U11, but decided I better check
all the components again in that section with the RF board disconnected and
out of the case.
I found much to my chagrin I had not installed D37 and D38! I had them
checked off in the manual as being installed, and I even wrote in pencil in
the margin on the next step where you put the rest of the V149's in the RF
board that I had 2 left over, but I failed to notice I had them left over
because I did not put them in the step before!, good grief.
Anyway I have a high BFO reading of 4917.60 and a low reading of 4911.98
with a difference of 5.62.
Thank you Don and to others that gave suggestions, and I do wish those
having similar problems well in their trouble shooting.
Upward and onward 73,
Tom Bewick, K2BEW
On Sun, Jan 20, 2019 at 8:22 AM Don Wilhelm <donw...@embarqmail.com> wrote:
Tom,
Good work on the VFO.
Before you replace U11, measure the resistance from the wire on the
carrier board to the lead of the SMD IC. Do that for all pins. The PC
traces on the carrier board are not thru-plated holes and sometimes
become damaged with soldering.
73,
Don W3FPR
On 1/19/2019 6:35 PM, K2bew wrote:
Don et al,
I tried a 15pf cap ( what I had on hand) at the source of Q19 to
ground and I got .025v on R30 that did not change with the adjustment
of L30, essentially no voltage.
So, I took it off and it went back to 4.5 volts. So, then I tried
Vicenç, EA3ADV's suggestion and I put 17 turns on the red wire of T5.
That got me a voltage of 8.5V on R30 with L30 bottomed out that I
was able to easily back off to a stable 6 volts.
I went ahead and did the voltage tests on the other bands and had a
nice range of 1.844 to 6 volts as my low and high on the VCO.
So, that's all set.
However, new problem. I went on to the test the BFO and I have 0000.04
kHz. on TP2, so it's not working.
I went to the trouble shooting guide and I have 0.058 Vrms on pin 6 of
U11 with the RF probe.
Looking at the archives of the reflector that would indicate that U11
is bad and I need a replacement, correct? or are there other things I
should look at first?
The good thing is I'm becoming very accustomed to the radio and
enjoying the trouble shooting.
Thanks for all the help, I really appreciate it.
73,
Tom Bewick, K2BEW
---
This email has been checked for viruses by AVG.
https://www.avg.com
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
