Multi-Rig Audio

[ames at nebula.decnet.lockheed.com]

Now here's an area I've started doing some experimentation, and
where we have seen some information over the reflector.  What I'm
doing is not low budget, but seems to make some sense (to me).
A standard unit to inerface two radios and several people is an
aircraft intercom.  So having deferred my flying lessons, I decided to
pickup a Flightcom IIId Intercom with a 32 second Digital Clearance
Recorder.  Of course it's stereo and has input/output for a tape
recorder and can take 4 headsets for the configuration I have.  It
works quite well for CW.  For Phone, well there's the problem.
	The David Clark headsets have a different kind of mike 
element, and these are all used with aircraft AM VHF radios.  The
electret mike is clearly more sensitive than a Heil HC-4, a gain 
issue.  The intercom applies an 8 volt bias to the HC-4 and has
a 1 k-ohm resistor in series, according to Flightcom.  They will not
provide schematics or details on the design.  A similar bias is
applied in the output to my rig.  As a result, the output is nil.
The logical next step is to try AC coupling thru a series capicator.
after that, perhaps buffer OP amps on input an output.  This is quite  
a small package electronically (hi density), so this is more than
tacking on a few leads on a large piece of electronic real estate.
	Has anyone used such an intercom?  Has anyone made such a
modification?  Has anyone progressed to the point where they are
using BOTH pilot and  co-pilot mike jacks?  Has anone figured out
how to use the DCR as a DVP?  I think this thing has a lot of
potential, I just haven't gotten very far, so far.

73, alan N2ALE/6

>From Jim Reisert AD1C  19-Nov-1993 1750 <reisert at wrksys.enet.dec.com>  Fri Nov 19 22:45:47 1993
From: Jim Reisert AD1C  19-Nov-1993 1750 <reisert at wrksys.enet.dec.com> (Jim Reisert AD1C 19-Nov-1993 1750)
Date: Fri, 19 Nov 93 17:45:47 EST
Subject: CT and serial numbers
Message-ID: <9311192245.AA25227 at us1rmc.bb.dec.com>

Jeff, N9FOX wrote:

>Hello, all.  I have a question about using networked CT in a
>contest which involves serial numbers.  During the SS CW weekend,
>we ran two computers networked together, each with CT v. 8.45.
>We had a real problem keeping the serial numbers consistent
>between the two computers.

I just spoke with Ken K1EA.  You *must* hit the INSERT key after typing in a
callsign.  This will "reserve" a serial # for your QSO, and the other
computer can go on its merry way logging more guys.  You will get your
reserved serial # when you actually work the guy.

If this is broken, please let me know ASAP.

73 - Jim AD1C

>From Jim Reisert AD1C  19-Nov-1993 1810 <reisert at wrksys.enet.dec.com>  Fri Nov 19 23:06:08 1993
From: Jim Reisert AD1C  19-Nov-1993 1810 <reisert at wrksys.enet.dec.com> (Jim Reisert AD1C 19-Nov-1993 1810)
Date: Fri, 19 Nov 93 18:06:08 EST
Subject: CT Networking
Message-ID: <9311192306.AA26609 at us1rmc.bb.dec.com>

------------------Reply to mail dated 19-NOV-1993 11:25:31.49------------------

Fred, KE7X wrote:

>We've got a problem for the 4M5I operation because our portable
>computers don't have enough serial ports for the normal network
>scheme - i.e. in/out on each com port to a single computer.
>Does anybody know if you can daisy chain to two computers using
>a single com port.  In from one on RxD and out to the other on 
>TxD?  If the daisy chain is a ring this would work if the software
>supported it.  Any clues anybody?  Thanks, 73, Fred KE7X

Ken K1EA asked me to commend Fred for coming up with such an elegant
solution to the single COM port problem.  Ken says this will work as long as
the computers are configured in a LOOP.  You can even wire the handshaking
wires the same way as the data wires, so that only 3 wires (data, handshake
and ground) go from each computer to each adjacent computer.  When a packet
is sent from the originating computer, it will go around the loop, in one
direction only (since there is a uni-directional interface between the
computers, not the bi-directional interface which needs two COM ports on
each machine) and when it gets back to the originator, it will stop.  You
can use this same loop configuration with a standard (multi-COM port)
network, as long as all computers are daisy chained in the loop.

I would suggest testing this three computers before you travel.

73 - Jim AD1C

>From tree at cmicro.com (Larry Tyree)  Fri Nov 19 23:27:58 1993
From: tree at cmicro.com (Larry Tyree) (Larry Tyree)
Date: Fri, 19 Nov 93 15:27:58 PST
Subject: SprINT
Message-ID: <9311192327.AA16735 at cmicro.com>


Well the vote as just about as even as the House NAFTA vote.  

To elminate some confusion, the dates were UTC and LOCAL dates since
the contest will start at 2300Z.  So that is Sunday afternoon.  

The January 2 people yelled slightly louder than the December 26
people, so it is resolved that the contest will be held on January
2 (Sunday) at 2300Z for two hours.  We will stick with 20 and 40 meters.

I will post the rules again sometime in December.  For those of you who
don't know what the SprINT is, it is basically the same as the NCJ
North American Sprint, except you send the name that you received in
your previous QSO.  Also, you can work dupes if you have worked at least
three other stations first.  Logs must be sent in via Internet within 72
hours of the contest.  

Hope all the people with American Airlines tickets make it to their
DX locations for the WW CW.  I know several people who may be stranded
and end up in the USA instead of some rare DX location.  My prayers
are with you and I hope it works out.  K6NA may not make it to 9Y4.
Maybe the people with the best travel agent will be in the top spots
this year.

My ticket is on United.

73 Tree N6TR (soon to be TI1C)