there seems to be devices that will allow for both transmit and receive to
one antenna, but you have to tune each channel or port for a specific set of
frequencies...its not wide open say for the whole 2M or 70CM band.
Perfect for repeaters since they always operate on fixed frequencies...but i
need the flexibility to receive the entire VHF and UHF bands as well as
transmit within the amateur VHF and UHF bands.
I just emailed sinclair to see if they make a product that will accomplish
this.
thanks for looking into it.
73
Colin, V A6BKX
----- Original Message -----
From: "John Miller" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, December 20, 2007 5:14 PM
Subject: Re: multiple radios, one antenna
> I'll find the person that has that equipment in my club and ask about it,
it
> could be a while though. I don't think it's a regular meeting goer or
overly
> active on the air right now but I'll look in to it.
> ----- Original Message -----
> From: "Colin McDonald" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Thursday, December 20, 2007 6:55 PM
> Subject: Re: multiple radios, one antenna
>
>
> >i did...nothing seems to come up for combiner, except VHF and UHF
combiners
> > for TV and satelite systems.
> > nothing for two way radio except some combiners for receive only for
short
> > wave rigs and scanners...
> > I searched on google with several different terms, but nothing.
> > It almost sounds like it either doesn't exist, can't be done easily, or
> > might have to be custom built by down east microwave, DCI or some other
rf
> > products company.
> > maybe i haven't looked hard enough at the sinclaire repeater
> > products...there might be something to that.
> > 73
> > Colin, V A6BKX
> > ----- Original Message -----
> > From: "John Miller" <[log in to unmask]>
> > To: <[log in to unmask]>
> > Sent: Thursday, December 20, 2007 4:47 PM
> > Subject: Re: multiple radios, one antenna
> >
> >
> >> I think that's where a combiner will help you out from what I'm told.
> > Check
> >> it out.
> >> ----- Original Message -----
> >> From: "Colin McDonald" <[log in to unmask]>
> >> To: <[log in to unmask]>
> >> Sent: Thursday, December 20, 2007 6:37 PM
> >> Subject: Re: multiple radios, one antenna
> >>
> >>
> >> > that is what i was thinking too.
> >> > Except a duplexer seems to allow for use of two transmitters and
> > receivers
> >> > within the same band, but not the same band pass...in other words the
> >> > filters have to be set up so that each transceiver can only talk or
> > listen
> >> > on a certain band width. without the two ever crossing.
> >> > So for instance, i could have one transceiver on 144 to 146MHZ, and
> >> > another
> >> > transceiver on 146 to 148 MHZ, but neither radio could just go where
> > ever
> >> > it
> >> > wanted between 144 and 148 without having to reselect the band pass
for
> >> > that
> >> > radio.
> >> > I guess what i am looking for mostly, is something that will trip a
> > switch
> >> > on all the ports as soon as i start transmitting on one radio.
> >> > This will keep the rf from going directly into the other radios while
i
> >> > transmit.
> >> > And, something that has a proper distribution amplifier built in so
> > there
> >> > is
> >> > no signal loss with multiple receivers going off one antenna...
> >> > I basically need a multicuppler for the receive side, but one that
can
> >> > except rf going back through it from the transmitter, and that will
> >> > instantly shut down all receiving ports while that rf is going back
> >> > through.
> >> > A multicuppler usually will receive from say 50MHZ to 2GHZ, so the
> >> > receive
> >> > is certainly wide enough.
> >> > A duplexer has fairly narrow filtering only a few megs wide usually.
> >> > anyway, i'm still searching for what i want.
> >> > 73
> >> > Colin, v a6BKX
> >> > ----- Original Message -----
> >> > From: "Steve" <[log in to unmask]>
> >> > To: <[log in to unmask]>
> >> > Sent: Thursday, December 20, 2007 8:08 AM
> >> > Subject: Re: multiple radios, one antenna
> >> >
> >> >
> >> >> A duplexer?
> >> >>
> >> >> ----- Original Message -----
> >> >> From: "Colin McDonald" <[log in to unmask]>
> >> >> To: <[log in to unmask]>
> >> >> Sent: Wednesday, December 19, 2007 6:53 PM
> >> >> Subject: multiple radios, one antenna
> >> >>
> >> >>
> >> >> here is a question for the list:
> >> >> I want to have my main VHF/UHF transceiver hooked up to my single
dual
> >> >> bander, while at the same time using that same dual band antenna for
> >> > another
> >> >> transceiver and a scanner at the same time.
> >> >> I don't want to have to manually switch the antenna over to the
> > different
> >> >> radios via an antenna switch.
> >> >> What i need is some sort of distribution device that will allow me
to
> >> >> transmit on either of the VHF and or UHF radios, without damaging
> > either
> >> > the
> >> >> other transceiver or the scanner. And then when there is no rf
being
> >> >> transmitted, to be able to have all 3 receive properly using the one
> >> >> antenna.
> >> >> My question is, is there such a device availible?
> >> >> I know about distribution amplifiers for receive, but i don't know
if
> > you
> >> >> can transmit through those, and i also need something that will
> > prohibit
> >> > any
> >> >> rf getting back into the other radios.
> >> >> I know that any receiver that is on the same band will be
desensatized
> > as
> >> >> soon as I transmit, but i am not concerned about that since if i
were
> >> > using
> >> >> a separate antenna, that would occur in the near field anyway.
> >> >> I require such a device because i can only really have one good dual
> > band
> >> >> antenna at any height and i have several different rigs i want to be
> > able
> >> > to
> >> >> use to monitor and transmit on, as well as listen on the scanner.
> >> >> I know that in multi-frequency systems, such as a public safety
> >> >> organization, or even public transit, they often have multiple
radios
> > on
> >> > the
> >> >> same band going at the same time for dispatch or communications
> > purposes,
> >> >> all using the same antenna....i suspect they use some sort of tuned
> >> > cavities
> >> >> to prevent desensatization...
> >> >> I need a little box that i can plug my antenna into, and plug 3
radios
> >> > into
> >> >> the other side and not worry about my 50 watts of rf on VHF getting
> > back
> >> >> into the antenna jack of the other radios and blowing out the front
> > ends.
> >> >> any help is appreciated in finding a solution to my wishes.
> >> >>
> >> >> 73
> >> >> Colin, V A6BKX
> >> >>
> >> >>
> >> >>
> >> >> --
> >> >> No virus found in this incoming message.
> >> >> Checked by AVG Free Edition.
> >> >> Version: 7.5.503 / Virus Database: 269.17.5/1190 - Release Date:
> >> > 12/19/2007 7:37 PM
> >> >>
> >> >>
> >> >
> >>
> >>
> >>
> >> --
> >> No virus found in this incoming message.
> >> Checked by AVG Free Edition.
> >> Version: 7.5.503 / Virus Database: 269.17.5/1190 - Release Date:
> > 12/19/2007 7:37 PM
> >>
> >>
> >
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.503 / Virus Database: 269.17.5/1190 - Release Date:
12/19/2007 7:37 PM
>
>
|
