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AO-51 10 Meter Antenna Answers

I hope this will clarify the AO-51 1-M antenna questions. On the "top" of
the spacecraft is a single ~18" whip antenna fed with semi-rigid 50 ohm coax
cable. In the topmost module is a 10 dB off-the-shelf (actually "from my
basement" is more correct) Minicircuits ZFDC-series directional coupler that
covers (effectively) DC-to-light.

The straight-thru port of the directional coupler feeds the preamp/power
splitter that provides the 2M uplink facilities.

The -10 dB directional coupler tap drives one side of a SPDT Coax Relay; the
other side connects to the L-band antenna. The relay arm then drives the
"SQRX" receiver (a much modified R-10 ICOM all-mode, all-band handheld
scanner) which serves as AO-51's "universal" receiver.

If you followed this, you see that the non-resonant whip antenna drives a 50
ohm coupler & receiver and it's not at all surprising that you need a fair
amount of xmtr "goo" to make it!

73, Tom
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