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
>>
>>
>
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