Re: [amsat-bb] Thanks for Coax advice. What about preamps?

[Mike73@xxxxxxx]

In a message dated 10/16/99 10:25:07 PM Eastern Daylight Time, 
rcrice@netropolis.net writes:

> Can anyone offer a clueless newbie some sage advice on preamps.

Hi Robert,

My personnal favorites are SSB. The 2000 and 7000 series. While not cheap, 
they are excellent in design and operation. I saw the URL for SSB listed in a 
previous note so I won't repeat it.

One of the best things you can do if you operate any mast mount preamp is to 
sequence it. Don't rely on the VOX or RF sensing circuit in it to switch from 
receive to transmit. This is especially important when you start to use amps 
(hard key your amps as well) with your rig. The idea is to have all 
mechanical relays switch and settle before you apply RF. If you don't do this 
you risk "hot switching" and eventually this will take its toll on the RF 
relays in the preamp.

I saw the note on SSB's not VOX switching correctly. At one time there was an 
issue with a small coupling capacitor in the RF detection circuit that could 
open under certain circumstances. To the best of my knowledge, this has been 
resolved.

73,
Mike, N1JEZ
AMSAT #29649
AMSAT Local Area Coordinator
"A closed mouth gathers no feet."
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