224.56 9600b Repeater Status
Thu, 4 Nov 1999 22:24:49 -0800
More progress to report.
While I was able to get the TX VCO working a couple of weeks ago
I've been fighting PA problems since then. 200mw drive out of
the VCO was giving only 1.5w out of the PA. Not very good.
I'd about given up and in fact had already ordered a 30W RF
module when I thought I'd give it another try.
22W out and stable as a rock :-)
This is within spec for the 220Mhz conversion and while a little
lower than I would like, it's a lot better than the 4W out of the
Now, what to do with the RF module when it arrives?
I may still use it since it should put out something in excess of
30W and the extra might be welcome, but I'll check the stability
of the existing amp out first.
Things still to do?
1. Stability of the VCO, Make sure it starts and stops
under a wide range of temperatures. I'm not convinced
I have it tweaked exactly right yet.
2. TNC and TAPR Modem, - Finish building and troubleshooting
3. Mate the TNC/Modem and the repeater, adjust levels, check
bit-error rate etc.
4. Check things like txdelay, rx setup time etc. Modify until I'm
satisfied with the performance. (someone may have to shoot the
5. Burn-in - Let it run for at least a week into a dummy load
with a real high duty cycle.
6. Final mounting in rack chassis
Thats the main list.
It's getting closer, I won't promise a Christmas present yet since I have
several other projects I'm working on as well (SFU link, Skagit EOC station)
but it's a possibility.
73's, Ken - N7IPB