Category Archives: Es’hail-2

Playing with the bird

April 1st, 2019

As soon, as the narrow band transponder was opened in February, I had my first QSOs via QO-100. Using an MKU LNC 10 in a 80 cm offset dish and my 3 m mesh dish for transmitting, made the first steps very (too) easy.

ADALM Pluto and 2 LNAs mounted at a W2IMU feedhorn

In the meantime I mentioned, some hams from the Netherlands, experimenting with ADALM-Pluto SDRs, had very good results. So I got one too and was amazed of variety of possibilities it offers. So I heard my first beacon on 9 cm and it was easy to produce a signal on 13 cm. Recently I got two broadband LNAs (I will call them “A” and “B”) from China and was curious to see how these can be used as power amplifiers too.

Power SourcePower in mW
Pluto 3
Pluto + LNA "A" 22
Pluto + LNA "B" 30
Pluto +LNA "A" + LNA "B"120

After some power measuring I connected the stuff to a W2IMU feedhorn, mounted on a tripod. No problem at all to find my signal on the NB transponder of QO-100. The estimated EIRP is about 2.4 W and results in a signalstrength of 12 dB.

Addendum: April 10th, 2019

3 mW are enough!

At least I mounted a DJ7GP patch feed with the bare naked Pluto in the focus of my 3 m mesh dish. the 3 mW were enough to produce a solid signal on the NB transponder. In this case I have 6 W EIRP to get 16 dB signal.