At 4/20/2004 04:31 AM, you wrote:
>As long as you don't experience mixing troubles it will work,
Using a coax "T" to connect 2 RXs to 1 ant. is not a good idea,
particularly if the RXs used have good front-end filtering (helical
resonators). The reason for this is that unless the frequencies of the 2
RXs are nearly the same, the front-end impedance of one RX will be mostly
reactive at the other RX's frequency. This reactive impedance will reflect
back in an unpredictable way to the T. If you're unlucky (as one unknowing
system owner was out here, running a deaf system this way for many years),
you'll reflect a short back to the T & effectively short out the RF at the
other freq. before it ever reaches the RX for that freq. OTOH, if you can
measure the input impedance of front-end "A" at freq. "B", you could use
that to make the RF cable connecting RX "A" to the T such that at freq. "B"
the T would be an open at that port. Probably more trouble than it's worth
considering how cheap RX power dividers are.
> the method
>more durable is building a mutli-coupler for the bandwidth you need -
>could be done with 7/8 hardline using taps at the electrical 1/4
>wavelength for each rx port, the cavity filter will be next in line -
>must be kept straight. You will have to experiment if you are trying to
>mix 145 and 15x as losses begin to show on the wider bandwidth that are
>never recovered,
Using a commercially-designed power dividers with broad-band port-to-port
isolation is the usual method of splitting off a RX antenna to multiple
RXs. I can't quite follow the method described above.
Bob NO6B
> adding some form of pre-amp here also carries in noise
>from other signals that can easily overload the rx of all ports.
>
>INECA wrote:
> >
> > Hello All:
> > Questions:
> > Does some problem exist if I share oneself RX antenna for two
> > repeaters with a "Tee?"
> > I thank any information in this respect.
> >
> > Regards
> > Ucaima
> >
>
>
>--
>73...Clark Beckman N8PZD
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/Repeater-Builder/
<*> To unsubscribe from this group, send an email to:
[EMAIL PROTECTED]
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
