23 cm

I will be using the 2.4 m Dish pictured on the 10 GHz Page,

23 cm feed horn, with relay and preamp as used for OX2K
23cm VE4MA feed, hybrid, relay and preamp


OX2K worked 3 June 2000, O reports both ways.  Signals peaked 519 later
Equipment at GM4ISM ... 100W, 0.47dB nf  Linear polarized 2.4m Dish
Audio Clip of the Greenland station (100W to 32m Dish) calling CQ after our QSO  OX2K  32Kb                                        3/6/00
Believed to be first GM-OX on 23cm, and first GM EME QSO?

4 June, worked OX2K again   529 reports both ways Power at GM4ISM raised to 125W
Worked OE9ERC, O reports exchanged, Erich was a good 529, maybe slightly stronger than the OX Dxpedition.
first GM- OE on 23cm??  .. first by EME

14 October

Heard several stations, immediately identifiable were HB9Q at about 539 peak.. OZ4MM at 529. G4CCH at abt 529, VE9DW at 419. These guys were easy copy in 3 KHz bandwidth. Links to WAV files.. 160Kb for HB9Q, 64KB for OZ4MM

Called HB9Q, got a QRZ and then PA went BANG!

after several more attempts to get the system running in time for skeds, and several more loud bangs. I gave up!

The PA has been fixed now, the output coupling loop was intermittent.. Not good. The anode decoupling had also punched through. Tried a test with W5LUA & OZ4MM, but could not hear a thing..

Still to find out why.. Must wait for the moon to come back up above my local horizon, which limits elevation to above 25 deg for most directions. Since discovered at low elevations the feed has a tendency to sag, causing an offset on the dish.. but probably not enough to cause problems. This has been corrected

Future operation on 23cm.
Near Future
Improvements to the PA have been made, now running 140W in the shack, 0.75dB loss to antenna (7/8" Andrews heliax)
VE4MA short circular feed horn now in use (above right)

Presently using preamp with 0.75dB NF (measured at Martlesham)
NF measuring set-up being modified for 23cm, and calibrated. New preamp under construction.. Hope to better 0.4 dB NF  Peter G3LTF's preamp to be returned.. Thanks Peter, I would not have had time to build one in time for OX expedition!
Possibility of high power operation this year with GM6BIG's YD1336 PA, last seen occupying the whole garage, but producing 500W key down.

VE4MA feed on loan from GM4LBV

My own YD1336 or YL1040 (TH347) cavity operational.. whichever is easiest to get going.. the 1040 is attractive HI but only 2 tubes!, and I want something meaty for 70cm.. I have 4 yagis refurbished for 70cm EME (ex GM3JFG)
extend dish to 3m, 0.35 F/D .  total of 5dB improvement on present system, not accounting for extra power.
I now have an operational cavity on 470-860MHz using a TH328.. Working on a retune to 23!


Initials to date 19. Unfortunatly a major PC problem caused the loss of 3 seperate hard drives on 2 computers, and some of my data was lost.. Backup was on a floppy, and it is corrupted ! I have records of the QSOs but date and time and detail is missing.






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