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[aprssig] 30M APRS and digipeaters...

Bob Bruninga bruninga at usna.edu
Thu Jul 12 21:05:04 UTC 2012


Stephen, AMEN.

I agree.  Few people run the dual-port GATING TNC's anymore, so
We should not have ANY path.  Makes the packet 14 bytes shorter and every
byte length hurts on HF.
Ill update the file NOW....... done

Bob, WB4APR

-----Original Message-----
From: aprssig-bounces at tapr.org [mailto:aprssig-bounces at tapr.org] On Behalf
Of Stephen H. Smith
Sent: Thursday, July 12, 2012 1:12 PM
To: TAPR APRS Mailing List
Subject: Re: [aprssig] 30M APRS and digipeaters...

On 7/12/2012 12:42 PM, Bill Vodall wrote:
> We do need an updated modern best operating practice for HF operation. We
> should either revisit the ECHO/GATE scheme or move to a new scheme closer
to
> something like the WIDEn-N used on VHF. 73 Bill - WA7NWP


I believe the original ECHO scheme on HF was adopted to prevent inadvertent
HF
digipeating when TAPR TNC2s configured for VHF operation were switched to HF
operation without resetting the internal configuration.   (Many TNC2 designs
including the MFJ 127x varieties included a hardware alternate-action
pushbutton switch that switched the unit from VHF 1200/220 tones to HF
1600/1800 200-Hz-shift HF tones.)

If the unproto path of a TNC2 had been set to the usual WIDE (or in those
days,
RELAY,WIDE) for VHF and then switched to HF without reconfiguring, the path
would be ignored, since HF digis would only respond to ECHO.    If you
actually
DID want digipeating on HF, you would have to explicitly reconfigure the
unproto path in the unit to ECHO.

ECHO became the entrenched standard on HF for decades, until the recent
influx
of newcomers familiar only with VHF conventions started arriving on HF due
to
a) low cost soundcard software TNCs and  b) code-free access to all HF
bands,

I don't think we need gating anymore, since there are now enough igate
stations
listening directly on HF that can pass HF packets directly to the Internet.
HF-to-VHF gating is the legacy of Kantronics KAM  dualport HF/VHF TNCs that
could do this (crossband digipeat) standalone with their internal firmware.
(As I mentioned in my previous post, my experience has been that I can
beacon
pretty much anytime from anywhere in North America and show up on the
Internet
WITHOUT being gated to VHF first.)

Shortening the packet path from ECHO,GATE,WIDE2-2 to just ECHO (or better
yet
nothing at all) will significantly increase the chances of a posit being
received successfully, since you are eliminating between 12 to 17
characters.


----------------------------------------------------------------------------
---

--

Stephen H. Smith    wa8lmf (at) aol.com
Skype:        WA8LMF
Home Page:          http://wa8lmf.net


High-Performance Software-Only Packet TNC
http://wa8lmf.net/miscinfo/UZ7HO-Soundmodem-Install-Ver-0.44-Beta.exe

High Quality Calibrated Static Maps for Any APRS App
    http://wa8lmf.net/aprs/PM9_StaticMap_Export.htm

  Vista & Win7 Install Issues for UI-View and Precision Mapping
     http://wa8lmf.net/aprs/UIview_Notes.htm#VistaWin7


"APRS 101"  Explanation of APRS Path Selection & Digipeating
   http://wa8lmf.net/DigiPaths







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