[Wswss] 23 cm Beacons

[Jim Klitzing]

Thought this message from Chuck, KD6VS, might be of interest to the group...

Jim - W6PQL

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Jim and all,

This last weekend I had the opportunity to do some real weak signal work on 
23 cm and wanted to recap for you what I discussed on the Tuesday 1296 WSWSS 
net.

I became aware that Jack N7AM is operating a beacon on 1296.093 from 
Bremerton, WA (CN87QO). Jack's beacon is running 2.9 watts to a 23 el. 
looper directed at Mt. Rainier.

On 23 cm I am running a TS2000X into a 67 el. WiMo at 35 ft with a decent 
horizon to the north. In addition, I use Spectran digital signal analysis 
software which has been quite useful copying weak beacon signals on 144 Mhz 
(including KA6LSL/b DM22 when it was operating).

Saturday I turned the WiMo up north to CN87 and set up the TS2000 with a 
filter bandwith of 400 hz and Spectran set to FFT=11,000, averaging set to 
32 and the audio input at -70 dB - very sensitive. Transceiver frequency was 
set to 1296.093 offset by 800 hz.

>From aprox. 7:00 am to 10:00 am I observed at least 6 traces on the water 
fall display that ranged from 1 dB to 3 dB above the noise and exhibited 
both +/- doppler shift of 20-50 hz an indication of aircraft reflections. 
Despite the 1-3 dB peaks, I was never able to hear any indication of the 
beacon signal in the headphones. The signal traces were +/- a few hertz from 
the frequency that Jack operates the beacon on and exhibited roughly the 
same doppler shift that I observe when monitroing N6XQ/b in DM12 (850 KM 
from CM97) and hear the audio for confirmation. Further, I never saw any 
detected signal that didn't show doppler shift indicating to me that there 
was no tropo path at all.

I was a bit surprised at this as the path to CN87 from my QTH is calculated 
to be in excess of 1,000 km and Jack is running only 2.9 watts. To make sure 
that I wasn't detecting some other spurious source I rotated the antenna at 
11:00 am to 90 degrees due east. Monitoring for the next two hours I did not 
observe any additional signals on that frequency. Although this is not 
absolute proof that what I detected was N7AM/b I think it would be 
relatively certain it was.

My purpose in writting this is two fold:

1. I hope to encourage Jack N7AM to keep his beacon going as well as 
encourage others to put  beacons on  if they are able. I believe that beacon 
op's seldom know how many folks appreciate their effort and investment.
2. Encourage more of us to study possible very long haul propogation and the 
possibility of really challenging contacts using digital software like 
Spectran.

Jack called me last night on the phone last night and gave him the details. 
He reports that he has received his new crystal and will be moving the 
beacon frequency to 1296.075 soon. Jack has a 30 ft 23 cm dish and I will be 
putting up 4 x 67 el. in the next week or two. Jack and I have agreed to 
establish a schedule once he is able to point his dish at the horizon.

Keep you all posted and would encourage anyone who is interested in this 
software to drop by my shack and I would be happy to demonstrate it's 
capability and power with either N7AM/b or N6XQ/b.

Feel free to forward this to other 23 cm WSWSS'ers as you see fit.

Best 73's

Chuck KD6VS CM97bf