UHF/SHF
23cm Wide/Narrowband
For 23cm I started out with ATV Amateur Television with a 24 element JVL design Loop-yagi antenna made from copper brake pipe and aluminium U section about 2m long. This worked very well for Receiving ATV and has a reasonable amount of gain, but I managed to get hold of 2x28 element G3JVL yagi's off-the internet on G3CWI's site including a 1W ATV transmitter. This was bought in dec 2003, the gear finally came in may 2004! ! ! The guy who I bought it off had some family problems and the gear was not one of his main priorities! All was ok in the end but I was about sick of waiting! ! .
Anyway, these antenna's were phased together and improved the 23cm setup dramatically and with the transmitter I could join in with the other local stations finally.
Next on 23cm I bought a transverter from gm4wll, a kit made by DEM in the USA.
Now I can hear the GB3MLE beacon over 80km away at S7 all the time, with the old homebrew antenna it is only about S1 ! ! Since then I have added a preamp on 23cm and switching relays at the top of the mast for tx/rx and replaced all the coax with mostly Andrews heliax LDF4-50 which reduced losses A LOT, this is the way to go with microwaves :)
Currently on 23cm i am using the Yaesu FT-736R 23cm module which i purchased in early July 05, this is a lot more stable than the transverter and the tx quality is much improved, but with the cable loss i have to the antennas i needed an amplifier. I recently bought a 23cm PA from DG0VE rated at 60W and this will eventually be going at the bottom of the mast (with the 2m/70cm/13cm PA's) driven from the 736 in the shack to cover the cable losses.
1.2GHz Block diagram Wide/Narrowband
(Handy diagram: Yaesu FT-736R 23cm module schematic (5Mb) - I hope you never need it !)
Recordings from the Tropo opening in Late January/Early February 2006 on 23cm SSB.
13cm (ATV for now!)
First on 13cm I used a video sender and receiver module from Maplin Electronics to send and receive on the FREE 4 channels and expanded the receiver to cover 2.2 - 2.7GHZ with a simple PIC chip and LCD display for frequency controlling the receiver by I2C data lines.
I was able to pick up many local signals and some a distance away with a home made loop yagi antenna (41element) When I still had the M3 licence I used to transmit with the video sender on channel 2 up to G1LPS 28km away with the standard unmodified 10mW ! ! ! (on one of the free channels... why not try it yourself if you have the M3 licence ! ! !)
Now with the repeater GB3KM up and running i have a good coverage !!. I'm now running about 25W from a Spectrian Driver amp that is on the output of a comtec 10mW tx module. The antenna at the moment is a SKY Minidish with a g3ruh helical feed in the loft! this antenna is for AO-51 tests but ended up being used for ATV!
I have Plans for 13cm Narrowband but thats another project for the future!
3cm Narrowband
3cm band is the newest of bands for me. Last Year i bought a DB6NT 3cm transverter Kit, and was very eager to get up and running on 3cm even though i'm beheind the North York moors when it comes down to getting south to the dx stations!
It took me about a week to get the kit built and tuned up, it certianly was worth the money and worked nearly first time i powered up. The only thing i had got wrong was a couple of diodes used for switching the tx/rx stage, anyway the output measured at work showed up 310mW output which i was pleased with as it only states 200mW on the specs !
The next thing was to bult an antenna, my first attempt failed for some reason. This was a modified sat LNB without the mixer stage and BP filter on the front of a sky mini-dish, just as a pre-amp... Nothing was heard but this might have been down to accuracy in the dish pointing! Next attampt was just with the end of some hardline ut-141 bared off at the ends poked up inside the LNB horn and actually worked! I was able to hear the weak carrier of GB3MLE over 80km away !!
I then built the G3PHO Horn form the appropriate bits of copper plumbing pipe, reducers and couplers, and made my own SMA to waveguide adaptor to match. This proved a much better method and was able to hear the CW keying on the beacon much stronger now also with a 60cm sat dish.
So far the only station i have worked (one-way) was peter G3PHO when he was at pocklington for the contest last year(2004) and he was perfectly audible with me on SSB but unfortunately he could not hear my small signal! (250mW) He was running about 4W into a big dish.
22nd of march 2005 was my next part qso... with G4XUM, i heard his signal from IO83SB 170km away at about rst319, quite surprising to hear a signal on 3cm over that distance, Martin could detect me but i was not readable.
27th March i managed to work G1GEY in SSB for the first time, we have worked CW a couple of days earlier but with weak signals. the 27th was very wet and foggy, ideal for 3cm!
Here are some recordings of Don's side of the QSO...
Since working Don and Martin i have worked G3PHO on the NY Moors with no problem and have worked Martin again at 5/7 two times in a row on contests(2005), must be a good path!
In May 2006 i have worked my first strong Rain Scater signals on 3cm.. G1GEY (IO94) and G4PBP (IO82)
Here are some recordings of the qso's...
New, September 07
I now have re-built my 10GHz Narowband setup into a new box, i have also added a 10W amplifier and G8ACE OCXO for beter stability. Photo's to come shortly...........
At the beginning of september the Manchester 10GHz beacon came on air from it's permanent location and much to my surprise it is audible all of the time!! distance is just over 100Km but straight through the Pennines! Signal is normally 41S due to the path but constant and very succeptable to rain scatter, regularly up to S9 for hours at a time! Rain scatter is seen on GB3MLE on 10GHz (at 80Km) but only at very weak levels in comparison.
Here is the patch plot to GB3XGH on 10368.810:
Mast Control Setup
2006: Currently updating the antenna setup with all amplifiers and antenna switching done at the bottom of the mast.
Shack Control Box : PTT control and monitoring of the remote power sensors etc..
23cm Remote Unit : First attempt without Proper sequencing... result: blown pre-amp :-/ ...duh Before now i have managed without any sequencing but having more power about does cause some problems!!
Try this simple Sequencer by G3SEK, works a treat. Only difference is that i used a 2200uF for a longer delay.
Mast Remote Cabinet : Currently seeking a weather proof cabinet to house the 2m/70cm/23cm amps, pre-amps ,relays, batteries etc..
3cm
Centre fed dish found at Harrogate radio rally on 3rd April..
It was a bit tatty so cleaned up removed some small dents and resprayed. Transverter now fixed to the rear of the dish.
GB3MLE 3cm as seen here on SpectrumLab, lots of sidebands!
GB3MLE 3cm with Rain scatter
23cm
23cm GB3MLE beacon aircraft scatter
