Successful 47 GHz Ham Radio Moon Bounce Test

Mitsuo JA1WQF was able to successfully decode Al W5LUA’s 47088.1 MHz QRA-64D signal that was bounced off the Moon on Feb 10, 2020. More tests are planned

Al W5LUA posted news of the achievement on the Moon-Net e-mail reflector:

These were one way tests with only me transmitting. At the moment Mitsuo is only running 1 watt but is actively working on a 10 watt amplifier. I run a 30 watt TWT which produces about 25 watts at the feed. The tube is a Hughes 932H driven by a Varian VPW2931 power supply modified for a second suppressed collector of the Hughes TWT. Both stations are running 2.4m offset fed dishes.

My system noise figure is 4 dB and about 2.5 dB at JA1WQF. Both stations are using the “Constant Frequency on Moon” (CFOM) technique of frequency control which allows you to hear/see the other station and your echoes on the same frequency. I started out by sending single tones to Mitsuo which he copied well and then sent several sequences of calls and grid. Mitsuo was able to decode calls and my grid at 1146Z and 1234Z. Signal levels were -23dB and -25 dB. DTs were spot on and frequency was within 13 Hz.

As a side note, the first EME on 47 GHz took place back in early 2005, with RW3BP working AD6FP (now K6MG), W5LUA, and VE4MA. VE4MA also went on to work AD6FP. It is nice to see a resurgence of EME activity on this band especially since we in the US are running the risk of losing the band to 5G interests.

The first EME QSOs that took place on 47 GHz utilized a program called MMCW which was a program written by a friend of RW3BP’s. The MMCW program required 10 minute transmissions in order to enhance the signal to noise ratio for optimum decode. It is very encouraging to see a WSJT mode provide similar decodes with less than 1 minute transmissions.

More 47 GHz tests are being run in the next few days with Manfred DL7YC.

We hope for similar success.

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