Ah, I wish it was that simple! It's been back for several days now
and runs its' cycle non-stop.
The only good thing about it is that it's every 30 Khz and not every
10! For the most part it stays away from my PSK and CW frequencies and I
can work around it somewhat.
Thanks, Jose es 73
Dave
KB3MOW
Jose A. Amador wrote:
It might be a switching PSU on standby mode. I know one TV set that
cycles in a similar way (producing some 'reverse TVI), even when the
numbers are not the same, it starts, charges the main capacitor, goes
into standby and restarts when its voltage diminishes under a certain
threshold.
73,
Jose, CO2JA
Dave 'Doc' Corio wrote:
Thanks for the info, Bruce. I didn't have a chance to record it or
measure it accurately before it disappeared Friday evening some
time. As
to if it's time synced, I would have to guess that it is. It was
extremely close to 10 seconds on and 5 seconds off, and the number of
pulses was 55 during the on period. Granted, timing it with a
stopwatch is not exactly precise, but it was close enough that I'm
reasonably certain it's timed somehow.
The simple fact that it stopped Friday night leads me to believe
it's some type of commercial activity. I've had the rig on a lot this
weekend, and haven't heard it once. It also stopped before I could log
exactly where it was. If I'm lucky, it's gone, never to return. I doubt
it, however. If it comes back, I'll get a recording of it and post it.
If you have a recording of yours, please send it to me! May not help,
but it sure couldn't hurt!
Tnx es 73
Dave
KB3MOW
Bruce Sawtelle wrote:
Hi Dave,
I have a similar type noise in our neighborhood. By doing some DF'ing,
we've pinned it down to a neighbor's house, but haven't been
successful yet in gaining their confidence to let us explore beyond
their front door. Can here it on VHF when we're at their front porch.
Is it time synced, i.e. is the accuracy such that it's being derived
from a 60Hz/Xtal time base. In my case, it's not. It comes on for
APPROX 12 seconds and goes off for APPROX 3 seconds, but if I listen
to it over a few minutes, it will drift up or down. Also, I noticed I
can hear it at ~ 16.7KHz offsets, which makes me think it could be
PC video related. Not sure if it could be switching power supply
related, I thought most of them were 100's Khz. Actually, It had been
across the full 20M band last year when we were DF'ing, but now it's
discrete. I have a wav file I can send you if that would help.
Fortunately, it's been down to S2-3 as of late. It also seems to be
tied to colder weather (thermostat control??). BTW, the neighbor is
300-400 feet away in a suburban area (70' x 120' lots) . W5AHC is
another ham in the neighborhood and he's ~100 fett closer and hears it
as well.
Hope this helps. Let me know what it ends up being.
tnx es 73
Bruce - W3NJ
