Domenico, I had no idea absolutely that you would have responded with such relevant experience !!! It is an amazing story to hear. The recent interest and work on "inflatable" antennas may be the most interesting chapter yet (ref: JPL DESCANSO publications) in antenna theory.
Thanks
-samudra
Hi Samudra, N3RDX
Early 13 august 1960 about 50 years ago I have received the ECHO 1A 45 mW beacons transmitting at 108.00 and 108.03 MHz and also I got an excellent visual of the big satellite balloon only looking at it in the sky with naked eye
Receiving radio signals and looking at the orbiting satellite at the same time it was a very exciting experience and I newer forget !
I was using a home brewed downconverter for 108 MHz with two low noise triodes 6AN4 in a front end grounded grid circuit.
The second IF receiver tuned at 27.963 MHz was an Hallicrafters SX-28 and the antenna was a qubical quad.
By the way the NASA and GSFC ground stations where transmitting to the reflecting surface of the above passive satellite a very very high EIRP at 960 MHz and 2390 MHz using big dishes.
The experience gained with the passive ECHO satellites demonstrates that they are not convenient at all so that the project was soon abandoned.
73" de
i8CVS Domenico