"digitania" wrote

1) Is it *possible* to connect multiple receivers to a single antenna?

2) Does is require the use of some sort of isolation circuitry for
each
receiver's feed? If so, what kind?

3) Can I then attach multiple antenna tuners to that single antenna
and
optimize each receiver's feed?

4) Would I be better off to try to disguise several seperate antennas
as
a single antenna - e.g. several long wires bundled together as one - or
would that cause other problems on the receivers' front ends?

A passive or active multicoupler is just what you want. These devices
electrically isolate each output (typically either 2 or 4 ouputs provided).
The passive versions have between 2-4 db insertion loss. The active versions
boost the signal so the loss is overcome (and then some). Active
multicouplers require a 12vdc power supply to them, usually about 200-300
milliamps.

Each output of a multicoupler could have an antenna tuner attached to it.
However, it is likely that trying to tune an antenna out of it's bandwidth
could result in unacceptable draw-down of available signal strength for
other receivers. This is even with an active multicoupler, which are the
only kind acceptable for any kind of DX-type work. Multicouplers are great
tools, but they have their limits! They are also prone to amplifying local
intermod (pager towers etc) when used in UHF bands. You have to choose the
bandwidth-type you require, and two major manufacturers below are well
known:

Stridsberg (very expensive) ~ $150, and
Industrial Communication Engineers (ICE), ~ $50.

Receivers don't care what form of input you give them, but by receivers we
do not mean portables. Most portable radios are miserable performers when a
high gain signal from an external antenna is connected to them. They are
made to do their best job with the provided whip or 12' or so of
inside-the-home external wire only. If you want to add several receive
antennas in parallel to each other that's not a bad idea either. But
bundling them together would be counterproductive, and a detriment to each
of their capabilities.

If you wanted to receive HF/SSB, SW, AM broadcast, VHF and UHF in one
antenna, I would suggest a discone, scantenna-type antenna. Even though
these usually advertise 25-1300 mhz reception, most of us have tried them
even on low-band SSB with pretty surprising results. Otherwise the wire
antenna will be the best bet for HF/SSB, shortwave and AM broadcast only.
Even your rain gutters can funtion in this capacity. Some enterprising hams
have even transmited through rain gutters, lol.

Hope this helps,

Jack
Virginia Beach