VK3NX
Australian Amateur Radio Station
Equipment on 3cm

- A homebrew transveter based on the DEMI board  is used
for the 10 GHz transverter.  The transverter is used as my
"terrestrial" transverter and incorporates a
homebrew 3W
amp  and the DEMI 8 W amplifier.  There is provision for a
low level (+10dBm ) output on the rear panel which when
selected disengages the internal PA's.  This low level RF is
used to drive the EME TWTA.

- The TWTA is an NEC  which produces 100 W  RF on
10368MHz  and with the associated piece of LMR600 I am
getting about 75-80W at the feed of the 3.7m dish.

-The LO is a homebrew design utilising the circuit in the
"ARRL Microwave handbook" as the basis and is locked to
a GPS derived 10 MHz signal with a "VE1ALQ"  PLL board.

-LNA  is a DB6NT preamp.  Measured NF  is 0.7dB  and the
gain is 26dB

- A W/G switch is used with a simple feed horn utilising a
single "VE4MA" style choke flange.  1 W/G to SMA
transition exists on the input to the preamp.

- IF frequency is 144 MHz.
3cm EME

NEW FEED WITH SUPER VE4MA CHOKE FLANGE
FITTED JAN 2015

Sun Noise = 14.8  dB  (SFU = 148)

Moon Noise = 1.65dB

CS / Gnd = 4.2

Audio Clips of 3cm EME:
RW1AW
Recordings taken at JA1WQF... on 2.4m
dish   (
Thanks Mitsu)
VK3NX received at JA1WQF
OK1KIR - VK3NX  QSO
Using a Large bolt of 22mm diam, (0.77wL), shaped to a point over ~ 2wL, the
WR75 Waveguide piece was heated and flared out to circular.  A 3 screw tuner
(utilising only 2 screws) was used to  achieve a 25dB RL.  A Super VE4MA choke
flange was fitted and adjusted for best illumination.  This  feed produced about
0.25dB more moon noise compared with the original feed which utilised an
"original" dimensioned VE4MA choke flange.
My Echoes on 3cm
Link to 3cm EME Log Book
HB9Q SSB