Re: 10Ghz last night


John Lemay
 

David

 

Thanks for the nice report. I guess the 20dB difference in power at each end explains my failure to hear you. A couple of points come to mind:-

 

…… Starting the contacts with dots or a carrier works well if the signals are not expected to be strong

 

…… The above is even more helpful if SDR or an audio waterfall is in use because it will show signals that are not yet audible – it’s really tricky beaming up on something you cannot hear.

 

…… As you were receiving a strong signal from me, it may have been difficult to find the optimum dish heading – which you would need so that I might hear you. Some radios, where each bit of the S meter represent many dB are particularly unhelpful in this matter.

 

That’s three points – I’ll only invoice you for two !

 

Importantly, don’t be put off by one failure between us. Conditions will change and it’s only a matter of time.

 

John G4ZTR

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of david656179 via groups.io
Sent: 28 October 2020 23:50
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] 10Ghz last night

 

I also extend my thanks to all who tried last night in what was my first 10 Ghz nb experience.  I was QRP with just 100mW at the waveguide probe.  G4ZTR was a massive signal with me but he did not hear me.  I had good fortune to hook up with G4ODA before the contest and he kindly made me his first contact at the start of contest, he was also a massive signal.  After may tries via KST and fails, G4CLA took time out to work me, he started with CW and then to SSB because I am yet to master it.  He was loud but had heavy doppler and other distortions.  Leicester, GB3LEX was a consistent signal on two clear bearings the 20 deg off one was much stronger however.  Since visually this has clear take off for many miles and as others have said rain scatter disappeared before start of contest, it seemed to suggest a strong reflection more locally to the beacon site.  I took the fact that since I could hear this beacon my RX was acceptable.  GB3CAM as expected, was a massive signal and regardless of beam heading, could be heard all the time.

The bulk of the stations that I should have been able to work were obstructed by a copse of evergreen trees that only five years ago would not have been a problem.  I will have to find a new position on the ridge to avoid or I guess with the aid of aircraft or rain scatter could still work those directions.

I am very interested to read that under some circumstances NBFM can produce better results.  Meantime I am going to attempt a tune up of the PA's and more importantly improve the frequency stability, also stopping the frequency shift that was noted by G4ODA.  And I think a bigger dish, however the old PW wideband penny feed dish is so easy from a mechanical point of view.  So lots to do.

It would be considered foolish of me to go portable alone on such a cold and windy night, I will and am suffering for it, but as somebody else commented, strangely I enjoyed the experience.  Also I neither got stuck in the mud or put the car or myself into the ditch which is a bonus.

73 David G6KWA

So thanks again everybody, see you again on 10 Ghz.


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