Re: GM4CXM/b on 3cm


Brian Flynn GM8BJF
 

It is a good signal in Edinburgh on an old BSB 30 cm dish. I can also detect it using Spectran on an Rx based on a LNB just using its horn as the antenna. On the dish it is about s4-5. It is drifting very slightly and has an interesting "hunting" on its frequency. I assume it is the xtal oven cycling. Gives it a bit of "character". I am nearly LoS to Ray's QTH

GM8BJF

IO85JV

--- In ukmicrowaves@yahoogroups.com, "Mark GM4ISM" <gm4ism@...> wrote:

Hi All
I am monitoring the beacon at Rays QTH
its is great to have a beacon again in the area. Thanks to Alan GM0USI and Ray GM4CXM and all others who have helped this project
It is 579 at best when i beam just slightly north of the direct heading, and can be detected al all points on the compass, being 519 to 529 in most directions

I am also monitoring the frequency.
My transverter is locked to GPS and the Lo is within 1Hz
The FT847 is not and does drift about a bit so to measure the frequency I inject a low level 2m signal from a 10MHz GPS locked sig generator and compare the tones received.
Thus the frequencies I am measuring are probably no worse that 10Hz out I could get more accurate but that takes some effort
The beacon drifts slightly with temperature, but seems to be settling with a lower range observed in the last 24 hours.
Last night at 3am it was on 10368.922,692. this morning at 08:00z it was on 10368.923,0 it has moved a few Hz lower again as i write.
There are some rapid step changes of tens of Hz occasionally and the keying does affect the frequency minutely but in general the beacon stability is very good.
The most important thing is that it seem to stay well within a typical receiver SSB bandwidth and with therefore appear on a waterfall display if you are looking for it.
Over the next few day I will report the maximum and minimum frequencies I observe and I will be able to then give a more accurate nominal frequency.

Please spot on beaconspot.eu
I note that one of my spots went to the cluster and got duplicated, the second 'version' had the last decimal place of the frequency truncated, apparently shifting the beacon 700Hz!
any one seen that before?

Regards
Mark GM4ISM

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