| VK3NX Australian Amateur Radio Station |
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| Equipment on 6cm EME: - The homebrew transverter utilises the N1BWT no tune transverter board as the basis of the system. I have now built 3 of these boards and each one worked as expected. - The LO is a homebrew design that is PLL locked to a GPS derived 10MHz signal using the "VE1ALQ" PLL board - LNA is a 30dB gain , 0,7 dB NF preamp from DB6NT - The PA is a TWTA running 120 W. I achieve ~ 100W at the feed. - The feed is a scaled version of the "RA3AQ" optimised septum feed that I built from 0.5mm copper sheet. |
5760 MHz ... was the first microwave band that I set out to "chase" echoes on. It took almost 2 years and a
move of QTH in order for me to achieve echoes. The original system was an extension of my "hilltopping" 6cm equipment. I ran a
transverter with homebrew amplifier chain utilising IMFET-3 FETs. The basic transverter produced 3-4 W and this was fed to a "dish-
mounted" PA utilising 4 x 5964-8 FETs. This produced approximately 20 W and with cable losses I was achieving ~ 13W at the feed. This
amplifier utilises the same type "WA5TNY" board that was used originally with IMFET 5964-3's : which was used for the very first QSO on
5760 EME.
The feed was a screw polariser and after extensive tuning produced less than 2dB difference through 360 degrees rotation on a dipole
Rx antenna. With the initial setup and very careful optimisation, I was able to finally hear my own echoes for the very first time in a 250
Hz Bw. After retuning of the amplifier I was able to produce closer to 30 W out and this allowed ~ 20 W at the feed. The first few stations
I worked had bigger dishes which compensated for my smaller setup and QSOs were achieved. The smallest station I have been able to
work was a one running 15 W into a 4.5m dish. We had a number of unsuccessful attempts whilst he was running linear polarisation, but
after changing to CP we succeeded.
The help I received from the whole 6cm EME community was marvellous and without them I would not be having the fun I currently am
with my EME activities.
Recently I have been lucky to come across a TWTA for 6cm thanks to a local ham. This unit produces > 100 W and after incorporating
the necessary safety / switching features it is now setup in the station. Needless to say finding my own echoes is now 7-8dB easier!
My SSB echoes are now QSA 5.
move of QTH in order for me to achieve echoes. The original system was an extension of my "hilltopping" 6cm equipment. I ran a
transverter with homebrew amplifier chain utilising IMFET-3 FETs. The basic transverter produced 3-4 W and this was fed to a "dish-
mounted" PA utilising 4 x 5964-8 FETs. This produced approximately 20 W and with cable losses I was achieving ~ 13W at the feed. This
amplifier utilises the same type "WA5TNY" board that was used originally with IMFET 5964-3's : which was used for the very first QSO on
5760 EME.
The feed was a screw polariser and after extensive tuning produced less than 2dB difference through 360 degrees rotation on a dipole
Rx antenna. With the initial setup and very careful optimisation, I was able to finally hear my own echoes for the very first time in a 250
Hz Bw. After retuning of the amplifier I was able to produce closer to 30 W out and this allowed ~ 20 W at the feed. The first few stations
I worked had bigger dishes which compensated for my smaller setup and QSOs were achieved. The smallest station I have been able to
work was a one running 15 W into a 4.5m dish. We had a number of unsuccessful attempts whilst he was running linear polarisation, but
after changing to CP we succeeded.
The help I received from the whole 6cm EME community was marvellous and without them I would not be having the fun I currently am
with my EME activities.
Recently I have been lucky to come across a TWTA for 6cm thanks to a local ham. This unit produces > 100 W and after incorporating
the necessary safety / switching features it is now setup in the station. Needless to say finding my own echoes is now 7-8dB easier!
My SSB echoes are now QSA 5.
FIRST CW ECHOES
"Spectran" trace of first
echoes in August 2006.
"Spectran" trace of first
echoes in August 2006.
| Audio *.wav file of 1st echoes |
| Audio Clips from 6cm EME: |
| OK1KIR |
| LX1DB |
| RW1AW |
| W5LUA |
| F2TU |
| 6cm EME |
| Current 6cm Equipment: |
| Current Performance figures as of May 2012: Sun noise = 11.2dB (SFU=67) CS / Gnd = 4.4dB Moon Noise =1.0dB |
| DL7YC |
| IK2RTI |
PA0BAT
| My Echoes at Apogee |