On Sat, 10 Nov 2007 01:58:28 -0600, Dave wrote:
"Helmut Wabnig" hwabnig@ .- --- -. DOT .- t wrote:
On Sat, 10 Nov 2007 01:04:00 -0600, "Dave" wrote:

Is there a fairly quick answer to the question of what is involved with
matching an RF amplifier to a whip antenna? I have built an active, tunable
antenna to assist my shortwave receiver, and it works wonderfully on the
110' random-wire antenna up on the roof, but only picks up the strong
stations with the whip. Those that it picks up come in great, but there are
others that it is able to detect but not lock on to and make intelligable,
IE BBC Africa, 7160 kHz around 0400/0500 UTC (and I am on the Gulf Coast
of Texas).

is the whip some sort of reduced size antenna?

The smaller an antenna is, the worse is the performance.

It's a 43 inch collapsable antenna (7 segments.) Maybe I just need more
amplification...

No. You need more antenna.

If you add amplification to a marginally performing antenna, you will
also amplify all the nearby interference: power line noise, dimmer
lights, electrical motors, poorly shielded TVs, etc. usw.

Sure, the desired signal(s) may come up in strength by adding more
amplification to a poor antenna, but everything you _don't_ want to hear
will be stronger, too.

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
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