fredag den 7. april 2017

144 MHz EME: CQ heard

Last evening, just before midnight, the Moon was high in the sky, and the Sun had set more than 1 hour ago. The degradation was about 2.0 which means good conditions. I watched out for EME-signals, and I used the EME-chat (N0UK) as a guideline for their frequency. The EME-chat is mandatory because you want to know where the different stations are calling. Below is a cropped screen-dump of the WSJT-X Wide Graph waterfall (times are in UTC):
OK1DIG calling CQ on 2m EME.
OK1DIG decoded by WSJT-X (JT65B). 
WSJT-X decoded the JT65B signal (sync tone at 1165 Hz) as OK1DIG calling CQ. His signal was pretty good and between -15 dB and -13 dB. His equipment: 4 x 17 yagi and 1 kW.

I could also see K1SCE answering the CQ (sync tone at 1389 Hz) He used 4 x 9 yagi and 1 kW, but he was not picked up by the other station. The signal from K1SCE was not strong (best -20 dB), but it was perfectly readable at my QTH.

If my SSPA was connected, I would have answered OK1DIG. My first priority is getting on the air - and flying to the Moon!

Best regards OZ1BXM Lars

lørdag den 1. april 2017

144 MHz EME: Graves radar 143.050 MHz heard

Today Friday 1st of April is my lucky day! I've heard the first radio signal off the Moon!

I listened for ham radio signals from the Moon after having erected my 2x6 vertical yagis. I listened most of the time on 144.120 MHz - but no stations were heard. I was disappointed. I had expected at least some stations be visible on the waterfall. The reason - probably - was lack of big gun stations.

The danish ham radio magazine OZ published "Experience EME using simple equipment" in their July 2015 issue. The message was clear: Use the French Graves VHF-radar signal as a beacon, and listen to its reflections off the Moon! The radar is located in 70140 Pesmes, France (locator JN27SI). It transmits a powerfull beam between 15 degrees and 40 degrees elevation. The azimuth angle is between 90 degrees East through South until 270 degrees West. The purpose is to track LEO satellites. As a side effect, the radar signal at 143.050 MHz will hit the Moon and bounce back to Earth.

The map below shows the location of the Graves radar. It is far away from my QTH.

OZ1BXM QTH and the Graves radar in France.
I used my EME station for receiving the Graves signal. My Yaesu FT-847 can easily tune to 143.050 MHz, and when I aimed the antennas towards the Moon, the radar signal (continous wave) was heard immediately and visible on the waterfall.

A screen-dump of the "Wide Graph" waterfall in WSJT-X is displayed below.

Wide Graph waterfall displaying the radar signal.
Kind regards from OZ1BXM Lars Petersen