Multiple FM tuners to only one antenna
In message , Richard
Harrison writes
Stats wrote:
"Is it possible to do this?"
Yes. Emitter, source, or cathode followers may be used, one for each
tuner to isolate the tuners from each other.
All the the bases, gates or grids can be fed from the same antennna
signal. Individual isolated signals are available at the emitters,
sources, or cathodes for the tuners.
Surely a bit too complicated? The simplest way is to use a passive
multi-way CATV splitter. With a 2-way you lose 3.5dB, 4-way 7dB, 8-way
10.5dB. If necessary, precede with a preamp. The isolation performance
will be more than adequate for your purpose.
Radio Shack or some similar supplier likely has a device such as this
with one input and multiple outputs available off the shelf that works
in the VHF TV and FM broadcast bands. Unlike the followers, it may give
you 10 dB or 20 dB gain on each output.
As I describe, a preamp plus splitter. I don't know what Radio Shack
stock, but in the UK, you can buy 40 to 860 MHz wideband units at
several DIY stores. Gains per output range from 0 to around 10dB.
Outputs 2 to 6. The internal splitting may simply use resistors (and not
use the low-loss ferrites used in CATV splitters), but they work fine.
Some have separate diplexed inputs for TV and FM. Cost $30 to $50.
Ian.
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