| |
PA2AGA > HDDIG 13.09.00 20:08l 206 Lines 7286 Bytes #999 (0) @ EU
BID : HD_2000_249H
Read: GUEST
Subj: HamDigitalDigest 2000/249H
Path: DB0AAB<DB0PV<DB0MRW<DB0ERF<DB0SAW<DB0MAR<DB0IL<SR2BGD<SR4BBX<SR9ZAA<
EC1L<EA7URC<PE1NMB<PI8HGL
Sent: 000913/1700Z @:PI8HGL.#ZH1.NLD.EU #:13663 [Den Haag] FBB $:HD_2000_249H
From: PA2AGA@PI8HGL.#ZH1.NLD.EU
To : HDDIG@EU
Date: Tue, 12 Sep 00 23:00:24 MET
Message-Id: <hd_2000_249H>
From: pa2aga@pe1mvx.ampr.org
To: hd_broadcast@pa2aga.ampr.org
X-BBS-Msg-Type: B
> they say...
Or run cross-band. I don't know why more people didn't do this. It is
so simple AND cheap(at least if your not on some radio-active hill).
Gets rid of all those cavities and duplexers - and only adds the
expense of some extra feedline and a second antenna - both pretty cheap.
------- 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: Tue, 12 Sep 2000 05:39:09 GMT
From: horseshoestew@my-deja.com
Subject: YAM modem at 2400bps? and other YAM questions
In article <srr1gmdict6135@corp.supernews.com>,
"Steve Sampson \(K5OKC\)" <ssampson@nospam.radio-link.net> wrote:
> > What about 2400bps? I remember that in the early 90's, a few of the
> > TNC manufacturers started to market 2400bps TNCs - which pretty much
> > took off like a Lead Zeppelin.
> I had a KPC-4 back then, and it did work (I seem to recall it being
> QPSK).
I tried to do some web searches to find info on 2400bps packet ops. I
came up with a big goose egg. The only thing that looked hopeful was
some old mail archive index of packet information from 1991/92 that
used to be stored at ftp.ucsd.edu (apparently some Brian Kantor-
maintained stuff). The index is still reachable, but all the files
seem to have been blown away.
KPC-4, huh. Well I knew that the KPC-2400 did 2400, but not the KPC-4.
QPSK, huh - that IS different. I sure would like to know the whole
story. Looks like this is all lost technology. Even the TAPR back
issues don't have much info - although I suppose the review of the KPC-
2400 in Nov. '87 might be of some interest(at least it would verify
whether it was FSK, AFSK, or QPSK).
> The problem was that 2400 wasn't worth the expense. The
> speed increase was offset by the long latency times (most everyone
> used simplex).
.. and I would think the error rate would increase. It seems that
2400bps is right on the edge of what will work with most off-the-shelf,
unmodified voice radios. In the lab, it probably worked OK, so these
high-compression heads went ahead and tried to market it. So, the
result was the proverbial "Lead Zeppelin".
> Maybe if they made the data rate 2400, and sent
> 1200 with FEC through it, it might have improved some of the
> long haul links.
Yes - THAT is a good idea. FEC... how about Interleaved Reed-
Solomon?! You wouldn't even have to lower the data rate to 1200.
Maybe just by 5-10%, or so. I've got a YAM modem coming. It comes
with a Beta driver for the Manchester Coding FSK 2400bps
implementation - but I would need to get the source code for it to
implement the error correction. I'm entirely capable of doing this.
------- 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: Tue, 12 Sep 2000 08:16:53 GMT
From: nomail@rob.knoware.nl (Rob Janssen)
Subject: YAM modem at 2400bps? and other YAM questions
horseshoestew@my-deja.com <horseshoestew@my-deja.com> wrote:
>> 4.8kb is better.
>Are you saying that 4.8Kbps will work with an unmodified radio? I
>remember people running K9NGs with Mocom-70s at 4800bps - but I'm not
>sure if they modified the beasties.
>Anyway, the original question still stands - will 2400bps(or 4800bps)
>work well with most radios, without modifications to the radio?
HAPN 4800 bps works OK without modifications to the radio, just connections
to it.
(i.e. you don't need to modify PLL time constants, filter bandwidths, etc)
Rob
--
+----------------------------------+--------------------------------------+
| Rob Janssen pe1chl@amsat.org | WWW: http://www.knoware.nl/users/rob |
| AMPRnet: rob@pe1chl.ampr.org | AX.25 BBS: PE1CHL@PI8WNO.#UTR.NLD.EU |
+----------------------------------+--------------------------------------+
------------------------------
Date: (null)
From: (null)
>They refuse to halt this
>practice and allow the hams who *want* to use radio ... use radio.
As far as understand, you are still free to set up and maintain your
own relay stations in more ore less inaccessible places, why don't you
do it yourself ?
>Those are the folks who killed the "friendship and goodwill" .
Requesting others do devote all their free time to do things that they
are not interested in, just to please some other hams and let them
play exactly as they please without considering others, is quite a
broad definition for "friendship and goodwill" :-).
Paul OH3LWR
------------------------------
Date: (null)
From: "Hank Oredson" <horedson@att.net>
Subject: Re: internet repeater linking
Lines: 44
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 5.50.4133.2400
X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400
Message-ID: <AFhv5.4473$M37.347248@bgtnsc07-news.ops.worldnet.att.net>
Date: Tue, 12 Sep 2000 03:45:36 GMT
X-Complaints-To: abuse@worldnet.att.net
X-Trace: bgtnsc07-news.ops.worldnet.att.net 968730336 12.73.133.181 (Tue, 12
Sep 2000 03:45:36 GMT)
Organization: AT&T Worldnet
To: ham-digital@ucsd.edu
"Ed_Woodrick" <Ed_Woodrick@email.msn.com> wrote in message
news:#kK2YdGHAHA.322@cpmsnbbsa09...
Ed, before you reply, it might be nice to read what you are about
to reply to, and perhaps even try and understand it.
> I'm not sure why some people using the Internet prevent you from using long
> haul links. On my radio, I can talk on HF or VHF and not have any worry
> about what other people do.
That is why I ask that you THINK ABOUT IT.
Here is what I said:
> > Some of us would like to forward packet traffic over long haul links,
> > both on VHF/UHF and on HF. The folks who bypass those links
> > using the internet prevent us from doing so. They refuse to halt this
> > practice and allow the hams who *want* to use radio ... use radio.
Do you understand the above paragraph?
> And I certainly hope that you aren't talking about broadcasting packet
> messages across the US, that's a really inefficient use of spectrum.
You use ham radio for what you want, I'll use it for what I want.
> But more importantly, it seems as if you are saying that Amateur Radio is
> slower than the Internet. Well, this just isn't true. If you are talking
> about the transfer of AX.25 packet data, then indeed, that mode is slower.
> But my radio signal is often many milliseconds ahead of an equivalent voice
> over IP solution.
Amateur radio is slower than the internet, for LONG HAUL links.
> But isn't it obvious that 1200 baud signals are significantly slower than
> 56kb and even faster connections? To compare the two is not a smart thing to
> do.
I did not compare them.
------------------------------
End of Ham-Digital Digest V2000 #249
******************************
You can send in your contribution to this digest by
sending an e-mail to: hd-group@pa2aga.ampr.org
or (via BBS-net) to: hdaga@pi8vnw.#zh2.nld.eu
Read previous mail | Read next mail
| |
