>From what I've been told, when 70cm first started to "take off" for FM
repeaters, repeater owners in the New York City metro found that they had
fewer issues with desense and overload if they flipped to a negative offset
(i.e. get the ham repeater Rx further away from the 450-455 commercial
repeater Tx's). By the time the coordination councils got on the ball,
there was a mish-mash of repeaters operating with either positive or
negative shift. As a "fix" (using that term loosely), they decided that all
of the "odd" pairs (44x.x25 and 44x.x75) would be negative shift and all of
the "even" (44x.x00 and 44x.x50) pairs would be positive shift. This became
the policy for the adjacent coordinators, and, like a bad cold, it spread up
and down the Atlantic coast from New England to Virginia as more 440
repeaters came online. It's an ugly mess, and one that I"ve made noise
about fixing by having everyone go to positive offset to align with our
respective neighbors to the west and south. Most of the coordination
councils have been in agreement, but others remain opposed, so nothing has
changed yet...
--- Jeff
> -----Original Message-----
> From: [email protected]
> [mailto:[EMAIL PROTECTED] On Behalf Of Bob Dengler
> Sent: Wednesday, September 19, 2007 1:19 PM
> To: [email protected]
> Subject: Re: [Repeater-Builder] UHF band opening
>
> Does anyone know why the New England bandplan has inverted 70
> cm pairs
> every 25 kHz (unlike the rest of the country, which is either
> all + or all
> - 5 MHz)? 25 kHz isn't close enough for any adjacent channel
> issues to be
> a concern.
>
> Bob NO6B
