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PA2AGA > HDDIG 27.09.00 09:00l 186 Lines 7319 Bytes #999 (0) @ EU
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From: PA2AGA@PI8HGL.#ZH1.NLD.EU
To : HDDIG@EU
Date: Tue, 26 Sep 00 19:51:38 MET
Message-Id: <hd_2000_263H>
From: pa2aga@pe1mvx.ampr.org
To: hd_broadcast@pa2aga.ampr.org
X-BBS-Msg-Type: B
> >have not heard anything else about it.
> >
> >So, can anyone shed some light on this?
>
> There have been a few discussions on TAPR's aprssig mailing list, but
> no conclusions. You should probably check to see if your area has a
> bandplan which addresses this. The bandplans differ quite a bit
> between areas and it will take a lot of coordination to establish a
> common frequency (as it did to get the 144.39 APRS frequency set up).
> In the absence of anything in the bandplan, check out simplex
> frequencies in your area. You'll probably find several that are not
> being used. The local frequency coordinator (listed in the ARRL
> repeater directory) should be able to help.
In Southern California, the SCDCC has considered such a question, but decided
not to suggest an allocation for 70cm APRS until the 2m APRS users state that
the frequency is too crowded to be usable. I have seen some times where my
TNC's rx light stays on for 5-10 seconds at a time because of APRS packets
crammed next to each other.
Unlike other modes, APRS is designed to use a single frequency REGARDLESS of
the number of stations. Moving its digipeater backbone to another frequency
also defeats its purpose. I'm not saying that it's not possible. However,
there is a reason why APRS is on the same frequency nationwide......
------------------------------
Date: Mon, 25 Sep 2000 21:54:52 GMT
From: horseshoestew@my-deja.com
Subject: UHF APRS frequency?
> In Southern California, the SCDCC has considered such a question, but
decided
> not to suggest an allocation for 70cm APRS until the 2m APRS users
state that
> the frequency is too crowded to be usable. I have seen some times
where my
> TNC's rx light stays on for 5-10 seconds at a time because of APRS
packets
> crammed next to each other.
>
> Unlike other modes, APRS is designed to use a single frequency
REGARDLESS of
> the number of stations. Moving its digipeater backbone to another
frequency
> also defeats its purpose. I'm not saying that it's not possible.
However,
> there is a reason why APRS is on the same frequency nationwide......
I would hope that if APRS applications do start popping up on 70cm,
that folks would standardize on one frequency, and standardize on
9600bps.
It will be harder to standardize on a UHF nationwide frequency, because
there isn't even a single standard UHF 9600bps coordinated frequency
yet. I think the ARRL came up with some "suggested" ones in the early
90's - but they weren't any good for the Southern California area,
because of the Pt. Mugu radar problem.
------- Stewart - N0MHS --------
Wireless High-Speed Networking and
Public Radio Services Information(MURS,FRS,GMRS,ARS,CB):
http://www.pubcel.com
Sent via Deja.com http://www.deja.com/
Before you buy.
------------------------------
Date: Mon, 25 Sep 2000 16:35:49 -0700
From: "Dana H. Myers K6JQ" <Dana@Source.Net>
Subject: UHF APRS frequency?
horseshoestew@my-deja.com wrote:
> I would hope that if APRS applications do start popping up on 70cm,
> that folks would standardize on one frequency, and standardize on
> 9600bps.
Well, I don't claim to be an expert on APRS, but it does appear to be
the case that APRS is really intended to run a "context" on one frequency
regardless of the geographical area or number of users covered. Isolated
"contexts" can exist, if you're just interested in a sub-set of users.
The protocol *seems* to attempt to scale to larger areas or number of
users by adaptive timeouts rather than a architecture of gateways
or proxies. I tend to question the capability of this approach myself,
but I'm not an expert. Perhaps I should have a closer look.
So, in the context of a nationwide APRS context, a single frequency
makes sense, but there's no reason why regional frequencies could
be used for sub-sets of the nationwide context.
> It will be harder to standardize on a UHF nationwide frequency, because
> there isn't even a single standard UHF 9600bps coordinated frequency
> yet.
This doesn't make much sense to me. It didn't seem all that easy to move APRS
to 144.39MHz just because they'd set up camp elsewhere. So, I tend to
disagree.
> I think the ARRL came up with some "suggested" ones in the early
> 90's - but they weren't any good for the Southern California area,
> because of the Pt. Mugu radar problem.
Is APRS really *that* old that the ARRL would have proposed nationwide
frequencies
in the early 1990s? I think APRS itself was only hatched around 1992. OK,
enough
of the hair-splitting.
Pt. Mugu is only one of many areas in SoCal plaugued by primary users of the
UHF band (of which amateurs are secondary users). Edwards AFB and Palmdale
Plant 42 frequently encounter RADAR interference - the only thing that's made
RADAR interference better is the number of base-closings during the 1990s.
I tend to suspect almost any location in the United States has local RADAR
often enough to notice.
Dana K6JQ
dana@source.net
(DM04 from 1990 to 2000, now CM88)
------------------------------
Date: Mon, 25 Sep 2000 18:22:10 -0500
From: "Steve Sampson \(K5OKC\)" <ssampson@nospam.radio-link.net>
Subject: UHF APRS frequency?
When a couple of us here locally wanted to experiment with 9600
when Gracilis came out with their card we set up on a frequency down
in the 430 range. This turned out to be a bad idea, as none of the
dual-band Omni's like Diamond and Comet had any gain down there.
We started out using beams, but found cheap Omni's with mucho
gain didn't work down there.
Anyway, if you do start something up, I would try to keep it in the
445 - 446 area. We have a 1200 baud freq of 446.775 in most of OK
which was used for BBS backbone back in its big days.
I think contacting a coordinator was a good suggestion, as they
will know the unpublished aux links, and help you from causing a
big stink. Even then I would put a recorder on the freq for a few
days (I use one of those radio-shack recorders that record when
the squelch breaks (get to hear the cops for a whole day in 15
minutes, ha), as there may be an un-coordinated Ham doing their
thing right smack dab where you want to do your thing.
"Fred Mahone" says:
> I have not been following the APRS talk close enough to know if there
> has been any discussion about a dedicated 70cm. APRS frequency.
------------------------------
Date: Tue, 26 Sep 2000 00:34:08 GMT
From: "D. Stussy" <kd6lvw@bde-arc.ampr.org>
Subject: UHF APRS frequency?
On Mon, 25 Sep 2000, Steve Sampson (K5OKC) wrote:
> When a couple of us here locally wanted to experiment with 9600
> when Gracilis came out with their card we set up on a frequency down
> in the 430 range. This turned out to be a bad idea, as none of the
> dual-band Omni's like Diamond and Comet had any gain down there.
> We started out using beams, but found cheap Omni's with mucho
> gain didn't work down there.
>
> Anyway, if you do start something up, I would try to keep it in the
> 445 - 446 area. We have a 1200 baud freq of 446.775 in most of OK
> which was used for BBS backbone back in its big days.
To be continued in digest: hd_2000_263I
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