From: Jay.Townsend@f3.n346.z1.spk.wa.us (Jay Townsend)
Newsgroups: rec.radio.amateur.policy
Subject: Errors in the ARRL Digital Committee's Report
Date: 30 Jul 92 17:25:28 GMT


 PF> Newsgroups: rec.radio.amateur.policy

 PF> Summary:

 PF> There are a substantial number of flaws in the statements made by the
ARRL
 PF> Committee on Amateur Radio Digital Communications regarding the technical
 PF> state of the art for High Frequency digital transmission.

 PF> Lack of coordination and channelization has led to situations where two
 PF> channels overlap in frequency; since collision detection depends on the 
 PF> ability to detect modem carrier, the channel capacity is halved.

 PF> All of these operating practices have simple remedies which fall under
 PF> the "Good Amateur Practice" clause of Part 97.

Well you have discovered the problem and now you should understand and be able
to fully support the position of the Digital Committee.  Lack of coordination
and channelization.  And your solution can only be obtained by requiring a
control operator on one-half of the circuit.  "Good Amateur Practice" can only
be ensured when WE listen on a frequency before firing off.  

Channelization is the only other solution and it has been rejected as a concept
due to 1) It only works for a few  2) There isn't enough spectrum
3) Who is going to assign the channels ? FCC, ARRL, ME, YOU. 4) Foreign
Phone bands (which BTW was the reason for the strange plan in RM 7248).

You are right that 150 Baud Packet would be better as well as all of the other
suggestions.  Have they been implemented? Tried? Sure they have, but I haven't
seen much new equipment.

It is my contention that the Digital Committee's proposal is not all that bad.
The lack of channelization is good.  The open to all part is good.  The lack of
specific modes is good.  The ability to try different things seems good.
If there are more than 52 people running un-attended automatic operation at the
present time.  And I know for a fact that there are !  Then whats the
difference in the long run.  One of two sides of a HF un-attended operation
will have to answer if there is an interference problem.  It is GOOD Amateur
practice to listen before you create a link.  And amazingly enough its real
hard when you are on a 250 Hz filter running RTTY on 14.092.5 to hear a station
on 14.091.5 running packet.  But contrary to all of your arguments it is my
experience that many if not most packet operators run LSB using 2.4 Khz
filters.  

 PF> 3. Comparing HF packet to other HF digital modes is fatally flawed.

 PF> Comparisons of digital transmission systems must be based on equally 
 PF> attained error performance and throughput.  

Nah, not really.  You are all concerned about moving messages with exact
replication and many of us Digital guys are a lot more interested in having a
QSO with a friend.  I'll give you an example.  Its a contest and I am beaming
240 degrees and its 0530Z.  I copy 2BW and it looks from the garble to be a
five letter call.  I am a lot better than the computer (tho K1EA's program
might also guess it).  A22BW for a triple multiplier.

Flaws in the Digital Committee's report.  Perhaps.  Flaws in analysis of the
entire digital spectrum with respect to a fair, good amateur practice, for all
users of that spectrum -- I think not.



 * Origin: Radio Therapy BBS (1:346/3)
Newsgroups: rec.radio.amateur.policy