10GHz


I have been QRV on 10 GHz since about 1978, initially using simple Gunn oscillator systems that were capable of line of sight communications. I built a JVL transverter in 1984, and had a couple of reasonable QSOs with it 'barefoot' running only 250uW.

This included the first GM to GI qso (GI8GJX/P) on SSB, from Cairnharrow to Agnews Hill. Signals were fully quieting on the WBFM system, and a genuine S9 on SSB.. Overall the FM sounded better! I have since worked Sam from my home QTH with S5 signals over a very obstructed path. The path is so bad that the 2m talkback was almost unusable most of the time, but 10 GHz was Q5 at all times. Mind you the 10GHz stations have improved!  I now run 40W and Sam had 12W. The high power capability (Thank you, Iain GM0ONN) obviously led me to the possibility of EME, and I gradually built up a good junk box of useful bits, including a 1.8m TVRO dish.

I finally obtained a waveguide C/O relay and within 2 weeks I had EME capability.. OK, held together with string....  literally. (I had planned for 3 weeks, but the contest weekend came a week earlier than that!) On advice from Charlie G3WDG, I opted for full remote steering from the shack. (Several groups have been QRV with a small team of helpers to keep the dish pointed the right way.) With a noise amplifier I could measure RX noise power and track the moon by myself.

Thanks must go to Mike G3JVL, Iain GM0ONN, Chris GM3WOJ and Charlie & Petra G3WDG / G4KGC for material help and advice.

QSOs resulted with DF7FJ o-o, G3WDG m-m, G4KGC m-m, and WA7CJO m-o

Others worked on the system include VE3ONT o-o with T9 note, SM4DHN and F6KSX

Listen to part of the QSO with WA7CJO (Real Audio Player required) size..60Kb

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  Waveguide filter design software can be found on the technical info page.

1.8m 10GHz EME Dish at GM4ISM                             2.4m Dish .. feeds for 1.3,2.3,5.7 10GHz available


 
 

I have now obtained a 2.4m Dish, (above right) and I am in the process of setting it up for 6cm EME
I hope to use it on all band from 1.3 GHz upwards, but I have only low power available for now.

As of march 2006, I am still not back on 10GHz eme, i have had transverter problems, and cannot generate sufficient drive to run the TWT at the dish, as a moderate feeder run is needed.
 
January 2008

Working on some Plessey 13GHz amplifiers using NE9000 series fets. The amplifier (for GB3TC) had 10dB gain at 10.4 GHz at the start.

After much fiddly snowflaking I have obtained over 700mW for 0dBm in. (the devices should be capable of 1.25W) I have not tried removing any of the existing matching patches, which are unusual in that they are some sort of ceramic material.

Hi res photo of th ere-matched amplifier. 380kB


 

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