ARLA/CLUSTER: JA1WQF successfully decoded W5LUA on 47088.1 MHz EME

[Miguel Pelicano]

Bom dia!!!

Enquanto eu ainda me debato para fazer um QSO nos 24GHz através de reflexão
lunar (EME), (está quase, falta só... o quase!!), nos 47GHz EME os testes
sucedem-se e ontem foi assim:

"

JA1WQF Mitsuo was able to successfully decode W5LUA’s 47088.1 MHz QRA-64D
signal today Feb 10, 2020. 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.                 73 de Al W5LUA

"

Esta madrugada o sinal de W5LUA também foi descodificado por Manfred,
DL7YC, que usa o LNA feito por Mitsuo, JA1WQF. Os cálculos preliminares
apontam para a necessidade de um sistema composto por: 2.4m dish, LNA NF
<2.5dB e 20 watts.

73, Miguel

CT1BYM
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