[BC] The Future

[Robert Meuser]

I agree and have done it with existing technology. My point, however, 
was combining very tightly spaced AMs with different technology.

R


Dana Puopolo wrote:

>The cable industry has been using adjacent channels for decades with zero
>trouble. They do it by monitoring and adjusting signal stregnths.
>Co-located FM's can EASILY exist 400 kHz apart with ZERO problems.
>It's the FCC that's the problem! In their "Alice in Wonderland" world, FM
>radios haven't improved a bit in 50 years.
>
>-D
>
>
>----- Original Message ------
>Received: Sat, 02 Dec 2006 11:52:47 AM EST
>From: "Mark Humphrey" <mark3xy at gmail.com>
>To: "Broadcasters' Mailing List" <broadcast at radiolists.net>
>Subject: Re: [BC] The Future
>
>On 12/2/06, Robert Meuser <Robertm at broadcast.net> wrote:
>  
>
>>I think multiplex sites will work with much closer channel spacing
>>thanks to totally different technology.
>>    
>>
>
>It's already practical to multiplex FM signals at less than 800 kHz
>spacing by installing two master antenna systems, so that the closest
>channels can be fed into different combiners, reducing loss while
>increasing isolation.
>
>An example in Germany is the Berlin-Alexanderplatz "Fernsehturm",
>where stations on 93.1 and 94.3 use the lower "UKW" antenna, with a
>co-located 93.6 on the upper antenna:
>
>http://www.d-no.de/fs-turm.htm
>
>Of course, the "space combining" schemes for FM IBOC, using separate
>antennas for analog and digital, work on the same principle.
>
>I manage a tower site in the western suburbs of Philadelphia where the
>rent is based on the length, diameter, and number of transmission
>lines, so everyone has an incentive to minimize tower loading.  Some
>of my tenants who are running trunking systems have come up with some
>clever combining schemes like this, so they can keep the number of
>antennas as low as possible.
>
>Mark
>  
>