EME on 1.3 GHz 

My first EME QSO on 23cm was actually just a test to see if it is really possible to communicate via the moon with just one single yagi. Heinrich, DJ9YW, calculated everything very thoroughfully. He is active on that band since many years and has gathered lots of useful experiences. We decided to create a "mobile" station so I can operate from different countries in Europe. Another goal was to use a maximum power of 100W, so I don't break the law in DXCCs like TF, 3A or EA9 where this is the power limit.

First time activity ever on 23cm EME from: 3A, 4O, 5N, 8Q, 9A, BY, C6,  IS0, OA, OY, T7, T9, TK, TF, Z3, ZA and ZB2

WSJT showed, that it is extremely powerful to decode very weak signals. I was using JT44 at the beginning and I was very successful with it. After all I activated some countries for the very first time on 23cm EME. At first I was using the IC-706, later the IC-706mkIIG and now the IC-7000. I also changed the mode to JT65 since Joe doesn't maintain the JT44 mode anymore. We picked the JT65C mode, which is already very powerful and still able to handle the large frequency drift on 23cm (that is causeed by doppler shift). Very helpful is the SpecJT where you can see the signal. 

JT65 screenshot QSO DL3OCH - DJ9YW

As you can see in the picture above, I had a QSO with Heinrich, DJ9YW. The weather was bad that day. It was rainy and windy and it was hard to keep the antenna pointing to the moon. It also was very cloudy and there were some heave rain clouds in front of the moon. However, JT65C still decoded pretty good. You can see a little peak in the red line. The green line shows the noise level and it is supposed to look as smoth as in this screen dump.

You transmit one minute and after that receive one minute. The audio signal will be sampled by the soundcard and saved in a wave file. After that, the signal will be decoded. The decoding needs some calculation from your computer so the processor shouldn't be to slow. I am using my old laptop for EME. It has only a 650MHz Celeron processor and it works good. Make sure, that the soundcard doesn't mess up you audio signal. For example the Line In input on my laptop "cuts" the lower and higher frequencies. I am therefore using the microfon input. That input transfers the audio spectrum linear.

(Just in case you are wondering about the red warning "1.000 1.000". I have no idea was was wrong that day but it is now working without warning.)

In the lower screen shot, you can see the spectrum of Heinrichs signal. The very thin line is the synchtone that seems to drift in frequency. That is caused by the doppler shift that is always changing. On that day, the doppler was moving about 12Hz per minute. In the spectrum, the whole area from 600Hz to 2.1kHz should be the same color which indicates that the audio spectrum is pretty much linear communicated. Is the color on the right brighter than on the left, check your audio input.



A QSO needs about 30minutes, depending how weak it is. Please have a look, how a JT65 QSO should run, so you do not have to transmitt more than necessary. In comparison to that is a CW QSO. Look at the details...



Procedure of a QSO in JT65

Procedure of a standard CW QSO

1 CQ DL3OCH   CQ DE VP9/DL3OCH   calling CQ
2   DL3OCH K2UYH FN20   DL2JRM answer
3 K2UYH DL3OCH OOO   DL2JRM 599   rapport
4   RO   599 TU rapport
5 RRR   73 DE VP9/DL3OCH    
6   73      


What the aginner don't seem to like on WSJT is maybe, that you do not hear anything except noise and the call signs do not have to be received completely to be shown in the display. The signal will be decoded once it is received. The result will be shown on your screen if the decoding was sucessful. If not, the deep search decoder gets active. The call signs and the others locator is known. From that, a so called pseudo message is generated and compared with the received message. The QSO text is shown, if both messages correlate enough. It is indicated with a question mark if the deep search decoder was active.

Unfortunately, this is criticized by some OMs. I heard sometimes, that QSOs in WSJT should not count for any awards and stuff like that. Hey, but how does that work in other modes? I really love CW but look in the table to the procedure of a CW QSO. Did you recognize that DL2JRM is working me but never repeats my call sign? How do I know he calls me? How do I know he has my call sign right? We don't know it. However, he will have my call sign right... a look up in the dx-cluster will tell him who is on which frequency. Also the 599 rapport doesn't have to be right...

I don't want to tell anybody how to do a QSO. I just think, that WSJT deserves more respect than vicious criticism.



Here some pictures about my activities on 1.3 GHz:

1,8m Segment dish

f/D: 0,36

Gain: 24dBic

Circular Patch feed (W0LMD design)


59 element yagi

Gain: 21.8 dBi

Lenght: 5 meter

Transverter (made by DJ9YW)

Typ: BJ 250 A

input: 50 MHz / 4 Watt

output: 1296 MHz / up to 100 Watt

specials: temperatur controlled fan, radio controlled clock, to use with 12V (car battery)

Transceiver IC-7000

Mode: USB; 2,4kHz Filter, NB on,

Comp/preamp/ATT/NR off

You can see Heinrich and me in the right picture. Heinrich is using a 4.5m dish with 33dBi gain and 540W power.

The red marked grids were already activated by me.

Not marked in this map: EL93 (C6), EL95 (W4), OM92 (BY), FH17 (OA)

Click on the map to enlarge the picture.

Where do I go next?