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[aprssig] Packet Node on 144.390 ?

wa7nwp wa7nwp at jnos.org
Wed Sep 13 08:44:54 UTC 2006


Ray McKnight wrote:

 > With a Pactor-II or III modem, capable of up to something like 33kbaud
 > throughput (due to sophisticated compression and transport protocols)
 > how is WinLink less efficient than 1200 baud connected mode packet
 > ack'ing individual packets and waiting for ack's etc through several 
layers
 > of nodes and BBS's?  Not to mention Pactor's ability to pass data
 > effectively up to -18db BELOW the noise floor.  Most packet modems
 > require tons of clean strong audio or else they go stupid and can't 
decode.
 > But let's not open that whole decade+ long debate over pre-emphasis,
 > proper tone levels, etc ad nauseum.  WinLink *is* far superior simply
 > because it generally relies on Pactor which is several magnitudes more
 > efficient than packet.


 >> You got that backwards Bob.  Winlink Email is just a part of what we 
can do with Packet and other Amateur Data modes...
 >>
 >> And no - it doesn't offer far superior performance either.   So many 
urban legends about Winlink.

> Bill, please explain your last comment.

Your posting proves my point. Urban legends..    Check your figures.  If 
they can get 33kbaud into less then a 3 KHz HF channel - they're on to a 
breakthrough in communications technology.   Pactor 3 is better then 
1200 baud packet - but then again so is almost everything else.  Pactor 
1 is about 200 bps raw,  AFSK packet is 1200 and Pactor 3 gets up to 
about 3300 bps under the best conditions.   So best to best -- you'll 
get about 3x the speed of "packet" with Pactor 3.  That's not quite 
several orders of magnitudes.

Add a digipeater or two and packet is down to Pactor 1 speed (200 bps). 
  Digipeaters give coverage at the cost of speed.   Add that noisy HF 
band and your Pactor 3 is also down to Pactor 1 speed...

On the other hand, the 9600 baud "repeaters" we had/have in the Puget 
Sound area will give that coverage and about 3 times the speed of Pactor 
3 -- at the expense of a second channel.

No question that Pactor 3 is the hottest thing going on HF.  It's great 
technology and the designers deserve the price tag they put on it.

Likewise Winlink2k is great technology.  Still it's only one facet of 
what we can do with packet and digital modes and it's not necessarily 
the best even for Email.

The folks that built the 56K repeater systems and 2 megabit links are 
off playing with IPV6 or unwiring islands or raising babies..   Our 
"current" packet technology is not what it once was.   That doesn't mean 
it won't be that - or much better - in the near future.  (The Europeans 
here are probably laughing at my use of the term "our"..  They've never 
stopped doing great technology and making progress...  Notice where the 
Pactor 3 comes from...)

I stand by my assertion that Winlink2k is only a portion of what we can 
do with packet and that it's not "far" superior performance.   The 
"superior" rating is even at risk..   Stay tuned.  :-)

73
Bill - WA7NWP

Has anybody here transfered a 3+ MByte .mp3 file by Pactor 3?  A 2MB 
ampr.org domain file?  Even a 350K Seti workunit?   How about just a 
plain old 200K JNOS .exe file?

  For the poor bloke who can't enter via HF and
> accesses WinLink from a packet front end, well maybe there's an arguement
> there.  I never think in terms of VHF/Packet and WinLink in the same
> sentance, because I will always choose the HF route because it is far
> superior
> and just plain more fun. VHF WinLink for me is merely a backup method
> in case there's nothing else available.  But now we're getting a bit off
> topic.
> 
> ----- Original Message ----- 
> From: <wa7nwp at jnos.org>
> 

>>
>> Bill - WA7NWP
>>






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