5760 MHz PA0EHG

Up
 

Updated on 09-12-14

In July 2009 I started building my 6 cm EME station.

The first thing I needed was power output. For this I had a TWT amplifier which had a defect in its power supply. I started to investigate the reason for this and found several components which where defect. After replacement it started up but gave far to high filament voltage on the TWT, so I had to switch it off. Further investigation gave me some more defects and after replacement of these the amplifier started up and after 2 minutes delay it even gave ready. I waited for a few minutes and than switched the TWT to operate and helix current looked normal. I had to connect dummy loads and a signal source to measure if it was bringing output. After some corrections to the measured results I found the TWT amplifier worked fine. I measured 56 Watt output on 5760 MHz which is very good. The amplifier was specified to deliver at least 40 Watt so I was quite happy with this result.

The next thing was to build a feed for my dish. I googled internet and found the septum feeds and also a feed from OH2AUE and decided to build them both.  I went to our local plumber which had copper pipe of 42 mm and 35 mm available. The 35 mm was needed for the septum feed and the 52 mm was needed for the OH2AUE design.

I build both feeds but found problems with the septum feed giving bad return loss, only -10 dB, and even worse it did not bring me the expected circular performance. I expect I must have done something wrong with the septum. I will give it a next try but for the short time I will give my time to try to be QRV and give it a go with the OH2AUE feed.


The OH2AUE design feed build by PA0EHG

The receiver and transmitter are also ready and now its time to get it mounted into the dish.
Hopefully it will work by next week, the activity weekend on 6 cm EME


It worked fine, I made 9 QSO's in this weekend. During the third QSO I blew my pre amp and had to replace the first fet giving me a bit lower performance. It was still good enough to hear my own echo's and work several more stations.

I still have problems with my pre-amp, during the activity of 30 may 2011 I again blew my pre amp and replaced it with the less performing pre amp with 1.2 dB NF.
With this pre amp I have 11.3 dB solar noise and 0.6 dB moon noise

Stations worked so far:

15 augustus 2009: OK1KIR

#(1)

-

OE9ERC #(2) -
W5LUA #(3) First PA to W
ES5PC #(4) First PA to ES
CT1DMK #(5) First PA to CT
LX1DB  #(6) -
16 augustus 2009:

 

G4NNS

#(7)

-

F2TU #(8) -
DF9QX

#(9)

-

7 NOVEMBER 2009 PI9CAM #10 -  
8 NOVEMBER 2009 OK1KIR   -
OE9ERC   -
OK1CA #11 -
W5LUA   -

24 april 2010

VK3NX   partial  
OK1CA   -
OK1KIR   -
F2TU   -

25 april 2010

IK2RTI #12 First PA to I

16 mei 2010

VK3NX #13 First PA to VK  
VE4MA #14 First PA to VE

30 april
1 may
2011

OK1KIR   -  
PA0BAT #15 -
OH2DG #16 -
W5LUA   -
CT1DMK   -
OK1CA   -

3 june 2011

SK6OSO #17 - Activity due to presence of SK6OSO

 

PA7JB #18 -
G3LTF #19 -

24 may 2012

DL7YC #20 - Activity due to the presence of TK/DL1YMK,
Unfortunately I was not able to work with Michael but made 5 new initials
PY1KK #21 -
F1PYR #22 -
SV3AAF #23 -
PA3DZL #24 -

  

6 cm setup PA0EHG
 
TX and TWTA behind the dish  

RX converter in plastic box

Feed in the dish with RX pre-amp and coax switch

 

 My own echo

My own echo 2

Signal from OK1KIR

Signal from OE9ERC

Signal from W5LUA