E2C or the later E2D possibly.
APS-145 uses UHF (including the ham band) for operation. There
is a newer RADAR on the later E2 series mini-awacs which also
uses UHF.
I used a pair of yagi antennas and two receivers (in AM mode) some
years back to 'listen' to their movement in the skies before I figured
out what I was listening to.
I only offer this as one possibly that I was able to determine definitively.
de AA5CT Jim
-----------------------------
On Thursday, August 12, 2021, 6:17:16 PM GMT-5, Christopher Wawak
<kc2ieb@wawak.org> wrote:
Hi! During the day, there is often what sounds like lightning noise from
~436-440 MHZ. It is an intermittent crackling, strong enough to totally
make the AGC crank and make it impossible to hear anything on satellites. I
turned off the power in my house, and disabled all UPSes and saw the same
noise. Tuning anywhere else in 70cm is fine, no noise further up the band.
The noise happens whether or not I’m transmitting, whether or not the
preamps are in line, on or off, and I’ve replaced all the coax!
I just set up a new Satellite ground station consisting of an icom 9700 and
M2 LEO PACK set of 2m and 70cm circularly polarized antennas. These are
connected to SSB.de preamps which have the gain adjusted to minimum. On the
70cm feedline near the receiver I added two mix 61 ferrite toroids. No
improvement. Feedline is approx 115’ of LMR400. I have also heard the noise
on an icom 705 with an arrow vhf / uhf hand held yagi satellite antenna. I
drove around the neighborhood and couldn’t get a good bead on where it may
be coming from other than “west”. It’s too hot to go on foot right now.
I’ve heard it since last weekend, and it’s been present most days, but
increases and decreases in the frequency of pops. I am keeping a log.
Here is a .wav recording from today:
https://drive.google.com/file/d/1Jl6wB-hJOpY0SDroQQQHw2uMUFdFwiF7/view?usp=sharing
Here is the waterfall, the horizontal wide lines are are impulse noise I
hear. No audio, but maybe useful.
https://www.youtube.com/watch?v=tbEWNWZnf1o
I have trouble direction finding this type of noise - it seems to come from
everywhere! Does it make sense to add more ferrites? I don’t think this is
common mode but…
Thank you
Chris KC2IEB
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