[MAMS] Up this morning

[Zack Widup]

I got up yesterday at 5:15 am to drive to EN50rl and got set up by
around 6:45 or so. I tried to work Dave KB0PE and John WB9PNU who were
on an AT&T site/hill in EM49ua. I could actually hear the signal of
one of them but found out I had a rig problem - I was losing
phase-lock on transmit. I tinkered with it for a bit but I couldn't
get rid of the problem. My in-line Whattmeter (displays DC
voltage/current/wattage/amp-hours) showed my battery voltage was 12.27
volts on receive, dropping down to 11.9 volts on transmit. I thought
that was the problem. I had just charged the battery and expected a
lot higher voltage. I thought it was going bad. It's only two years
old. I wouldn't think it would be going bad so soon, as I have been
taking very good care of it.

Anyway, I packed up and went home. When I got home I set up everything
exactly as it was in the field, except I used a power supply instead
of a battery. Everything worked fine. No phase-lock loss on transmit,
the lock loop voltage remained rock solid, I got 2.5 watts out on
transmit as I expected. I tried turning the voltage on the PS down to
11.6 volts and it still worked fine. I have built into the transverter
a little circuit to assist in keeping the phase-lock circuitry stable.
It steps up the 12 volts to about 18 volts, then uses a 7812 to
regulate it to 12 volts. The circuit I used will reliably produce 18
volts out when the input voltage drops to as low as 4 volts; it just
draws more current. I could detect no problems with that, either.

Later on I tried it with the battery again at home. Again, everything
worked and it remained phase-locked. I have no idea what was wrong on
the hill. Maybe it was just an attack by Murphy. It did this same
thing once before, about 3 years ago, with same results when I checked
it out later.

I hope this doesn't happen too often. If it does I might have to go to
a DFS LO scheme for 10 GHz like I'm working on for 47 GHz.

I am getting a cold and it hit me really hard last night. I slept in
this morning. I don't want to push it too far just for a contest.

Maybe it's just as well that I didn't drive to Wisconsin this weekend.
I'd hate to have all this happen in the middle of nowhere and far away
from my test equipment.

73, Zack W9SZ


On 9/16/12, Dave Sublette <k4to at arrl.net> wrote:
> Good morning all,
>
> I am up and running this morning if anyone wants to try a sked.
>
> Dave, K4TO
> EM77wx
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