-------- Mensaje original --------
Asunto: SPAM - Radar y la banda de 440 mhz
Fecha: Sat, 17 Oct 2009 18:26:53 -0300
De: MINECO <leadercomm@...>
Responder a: MINECO <leadercomm@...>
Para: LU2HAM <lu2ham@...>



/Hola Mario/
/En usa todos estan migrando a la banda de 900 porque ya no se puede
usar mas la banda de 440 porque los militares la estan usando en los
radares de alarma temprana ( /Pave Paws radar has forced 440 systems
off the air./ ) estos radares trabajan con 150 Kw average son del tipos
SAR ( synthetic apperture radar)/
/Bueno ya vendran por nuestras bandas de 440 Mhz aqui en el sur ( sur
(sub) desarrollo K)/
/Ponela en el foro ya que yo no se que pasa me rechaza cuando quiero
subir algo/
/cambien mi email a leadercomm@...
<mailto:leadercomm@...>/
//
/Un abrazo/
/atte/
/Ricardo/
/LU8KAW/
//
//
/
*From:* Ed Yoho <mailto:w6yj_yahoo@...>
*To:* AR902Mhz@yahoogroups.com <mailto:AR902Mhz@yahoogroups.com>
*Sent:* Friday, October 16, 2009 11:36 PM
*Subject:* Re: [AR902Mhz] 900 MHz expansion...
/
Kris Kirby wrote:
>
> Vester Scott threw out a proposal some time ago in SERA-land about how
> to deal with the issue. I see this group is based in California and I
> understand conditions have changed as users have vacated 440MHz for
> 900MHz.
That is in northern California where Pave Paws radar has forced 440
systems off the air. Luckily we do not have that problem in southern
California.

>
> My proposal would be to set for 15KHz or 12.5KHz channels, from 927.9875
> down to 927.1(ish) MHz, flat at a 25MHz split.
We currently have 12.5KHz channels with a 25 MHz split and they are
pretty much fully in use. Thus the band plan change.

>
> a) Full duplex links would be coordinated like repeaters, with a 25-MHz
> offset.
They currenty are.

> b) Simplex links would be inside of 903-926MHz.
See below.

> c) All receivers and transmitters would require PL, DPL, or another
> signaling format to prevent random interference from opening the
> squelch. Carrier squelch is not permitted.
> d) "Clear coordinations" would be reduced according to fade/coverage
> predictions. Coordinations ranging from 30 miles to 120 miles would
> be evaluated and considered for use.
>
> The part I mostly disagree with is "no high to high linking" How do you
> get an acceptable fade margin when operating on a LOS band without being
> "high"?
Any site that is allowed to have a low TX / high RX to link to a normal
low RX high TX site would make that site useless for anyone else
attempting to put up a 900 repeater as the 902 TX would kill the
co-located 902 RXs.
The idea was to keep all high level RXs on 902 to keep the noise and
adjacent channel levels under control. To link from mountain A to
mountain B, the link _must_ go to a ground altitude site and back up. A
larger initial investment, but it is the only way to keep 900 available
at all sites.

Ed Yoho
W6YJ


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--
LU2HAM
Mario Wolcoff
P.O.BOX 65 Córdoba Argentina
QAP en FO-29, ISS, AO-51,VO-52 AO-07 SO-50
AMATEUR RADIO the original "Wireless communications"