[Hallicrafters] "Airplane" Noise on Short Waves

[Todd, KA1KAQ]

Scott - 

This was a very distinctive, steady BRRRRRZZZZZZZZZZ sound, not unlike
a prop engine at full throttle. Someone (I think Gary) pointed out
that there were/are jamming machines used by the former Soviet Union
to block programming from VOA or any number of sources they did not
want reaching their subjects. More recently, Iraq used jammers against
Iran for the same basic reasons. If you came across one of these
signals, you'd know it in a heartbeat. Very distinctive sound, like a
thousand pound bumble bee.

Teletype or high speed dittybop had more of a CW/telemetry sound in
comparison. One of the things I hope to do this summer is get one of
my old mod 28 TTY machines back up and running. Nothing quite like it.

Then there was the notorious woodpecker roaming the bands. This was
discovered to be OTH (Over The Horizon) radar used by the Soviets
during the Cold War. IIRC, we had something similar up in Northern
Maine around Loring.

While it's not really sad that these old signals are now pretty much
gone from the band, what is sad is what has replaced them: crappy home
electronics! Yesterday I decided to see if I could track down some odd
noises coming through on HF. Loudest was the Dish Network receiver.
Unplugged it and found new sounds, like the VCR clock and the clock in
the AM/FM stereo system receiver. Even the TV makes some odd chirps
when not on. Unplugging them all produced much quieter reception. Next
I need to figure out if a better outlet/power strip will clean them up
or if the noise is being broadcast through the air, not just the power
lines.

~ Todd/'Boomer'  KA1KAQ

On 5/2/05, Freeberg, Scott (STP) <Scott.Freeberg at guidant.com> wrote:
> I remember hearing airplane noise as well as a kid with my shortwave.  I wonder if it was RTTY broadcast.  When I was a radioman in the Navy during Viet Nam, I used copy RTTY fleet broadcast.  I sounded like an airplane I guess.  It consisted of a many individual RTTY channels with super narrow shifts, transmitting in that bandwidth.  With a really good receiver you could slowly tune up the frequency and pick out the individual mark/spaces for each RTTY channel within in 3 Khz or whatever bandwidth.  Do you think thats what the airplane noise is?