With stock construction (with C91, .001uf, C88, 68pf and RC15, 100uh choke
installed) I found instablity in the VCO from about 7175 to 7860 KHZ.
After contacting Elecraft I was told to remove RC15 and replace it with a
wire and shorten the leads of C88. The VCO instablity was still there.
After being advised to keep the leads short I cut any excess leads from all
the IC's that are in the VCO circuit. (Please note that all chips are
soldered in except the controller chip U1). this didn't help at all.
So I tried replacing the wire short where RFC 15 was, with a ferrite bead.
Now the instablity was only from 7800 to 7805 KHZ.
The next thing I tried was replacing C88 with a 100pf silver mica capacitor.
It is somewhar larger then the origonal capacitir but I managed to keep the
leads short. The VCO problem is now gone and the rig seems to work
flawlessly. I have been using it a lot on PSK and even had some ssb
contacts. I still got a lot to learn about the rig and the DSB module but
that will come with experiance. Thanks to all for your advice and
information.
Again, thanks to all,
73
Dave KD1NA
_______________________________________________
Elecraft mailing list
Post to:
[hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
http://mailman.qth.net/mailman/listinfo/elecraft
Help:
http://mailman.qth.net/subscribers.htmElecraft web page:
http://www.elecraft.com
Locked
