QRZ! Ham Radio 5/QRZ Ham Radio Callsign Database - Volume 5.iso/digests/digital/940272.txt

Internet Message Format | 1994-11-13 | 21.8 KB

Date: Mon, 15 Aug 94 04:30:17 PDT
From: Ham-Digital Mailing List and Newsgroup <[e-mail]>
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Subject: Ham-Digital Digest V94 #272
To: Ham-Digital


Ham-Digital Digest          Mon, 15 Aug 94       Volume 94 : Issue  272

Today's Topics:
                            Help with info
                 Need mods to do FSK on Alinco DR-600
                        Packet BBSs for Unix?
                       Packet Node Info Wanted
                  PK-88 to Kenwood TM-231A interface
     simptr21.zip - Generic TNC comm program (packet, rtty, etc)
                       Smallest MultiMode TNC?
                           TAPR FTP SITE???
            Widrow-Hoff LMS algorithm for DSP??? (2 msgs)
            Windows 3.1 and Baycom Modem TCP/IP networking

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Problems you can't solve otherwise to [e-mail].

Archives of past issues of the Ham-Digital Digest are available
(by FTP only) from UCSD.Edu in directory "mailarchives/ham-digital".

We trust that readers are intelligent enough to realize that all text
herein consists of personal comments and does not represent the official
policies or positions of any party.  Your mileage may vary.  So there.
----------------------------------------------------------------------

Date: Sat, 13 Aug 1994 17:54:00 GMT
From: ihnp4.ucsd.edu!dog.ee.lbl.gov!agate!iat.holonet.net!bthouse![e-mail]
Subject: Help with info
To: [e-mail]

MS>From: [e-mail] (Mike Sheridan)
  >Newsgroups: rec.radio.amateur.digital.misc
  >Subject: Help with info
  >Date: Sat, 6 Aug 1994 06:54:32 GMT
  >Message-ID: <[e-mail]>
  >Organization: jakesys - Public Access UNIX - Manitowoc, WI

MS>Can anyone steer me into info on how to get started with packet radio
  >with a 486 clone?
  >---

   Hello Mike.  You have the main thing needed for packet radio.  Just
   get you a tnc(terminal node controller) and a two meter radio. a
   Handy talkie works well, or you can use a mobile rig.  Most use HT's
   because they are less expensive used.  You need to get software for
   packet.  If you use Procom, it will work very good.  You just set it
   up in the dumb terminal mode.  Then get the manual out for your tnc,
   and start programing the commands you will need for packet.  There
   are many programs out there, but I would suggest using a dumb
   terminal for a while to learn the commands and kind of get familiar
   with it.  I use a Tandy 486 machine, and it works very well.  You
   don't have to have too much to run packet,  as it doesn't take much
   memory to run it. If you have anymore questions, please let me
   know.  Cul....Mike, KE4CLE


 * QMPro 1.50 42-2694 * All rising to a great place is by a winding stair.

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

Date: 13 Aug 94 08:00:00 GMT
From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!gatech!wa4mei!totrbbs![e-mail]
Subject: Need mods to do FSK on Alinco DR-600
To: [e-mail]

Hi Rob,

ftp to oak.oakland.edu and look in /pub/hamradio/mods/alinco. If it
isn't there message back to me and I'll look in my my mod file
collection.

Regards,
Steve Diggs

----
Top Of The Rock BBS - Lilburn, GA         SYSOP: Steve Diggs
UUCP: totrbbs.atl.ga.us               Snailmail: 4181 Wash Lee Ct.
Phone: [phone]                           Lilburn, GA 30247-7407

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

Date: Fri, 12 Aug 1994 03:00:27 GMT
From: ihnp4.ucsd.edu!usc!cs.utexas.edu!convex!news.duke.edu!eff!news.kei.com!ssd.intel.com!chnews!ornews.intel.com!ibeam![e-mail]
Subject: Packet BBSs for Unix?
To: [e-mail]

Greetings all.

    I'm relatively new to the packet scene, so if this is an obvious question,
please forgive.

    What I'd like to find is code for a packet BBS that will work on a Unix
box (specifically, SunOS on a Sun 3/60).  Provision for either BBS operation
or direct login (sort of a packet getty) would be fine; from that point I
could hack the source either way.

    Does such a creature exist?  If not, do any of the common BBSs for the
PC (W0RLI, etc.) come with source?  I'd like to avoid starting from scratch
if at all possible.

[The next obvious question is if there already exists a packet->UUCP
gateway, but I'll save that for when I have spent more time goofing around
with packet in general...]

Thanks,
Rob
--
Rob Knauerhase [[e-mail]]  Intel Mobile & Home Architecture Lab
  "Always listen to experts.  They'll tell you what can't be done, and why.
   Then do it."   -- Robert Heinlein (Lazarus Long)

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

Date: Thu, 11 Aug 1994 14:40:25 GMT
From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!vixen.cso.uiuc.edu!usenet.ucs.indiana.edu!indyvax.iupui.edu!jsissom.dmed.iupui.edu![e-mail]
Subject: Packet Node Info Wanted
To: [e-mail]

Interesting, an Amateur Radio mode where DXing is discouraged!  This is a new
one. . .

I agree that people should use their closest BBS, but there shouldn't be any
problems with people node hopping to see how far they can get!  Experimenting
is what ham radio is all about, isn't it?

Jay

>::Arrrgh! You're a digi Dxer, the bane of network existance. :-);
>::
>:;Really, we've spent a lot of time educating our users to stay on
>:;their LAN and let the network do the forwarding. All it takes is
>::a couple of digi Dxers accessing a distant BBS to bring a 1200 baud
>:;trunk to it's knees from retries and collisions.

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

Date: Thu, 11 Aug 1994 14:44:42 GMT
From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!vixen.cso.uiuc.edu!usenet.ucs.indiana.edu!indyvax.iupui.edu!jsissom.dmed.iupui.edu![e-mail]
Subject: PK-88 to Kenwood TM-231A interface
To: [e-mail]

Last night, I built a cable to connect my PK-88 to my TM-231A.  I don't have
the pin out here, but it was quite simple.

Unfortunately, the DCD lite on the PK-88 stays on when the radio is squelched.
Because of this, the PK-88 will never tell the radio to transmit.  It
receives fine.  If I am tuned to a repeater and there is no sound coming
through the repeater, then the DCD lite is off.  I'm kind of confused.  This
PK-88 has been hooked up to my Icon IC-28H for years with no problems.

Has anyone else seen this problem, and solved it?

Thanks
Jay
KA9OKT
[e-mail]

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

Date: Sun, 14 Aug 1994 14:17:57 GMT
From: ihnp4.ucsd.edu!agate!spool.mu.edu!nigel.msen.com!simtel.coast.net![e-mail]
Subject: simptr21.zip - Generic TNC comm program (packet, rtty, etc)
To: [e-mail]

I have uploaded to the SimTel Software Repository (available by anonymous
ftp from the primary mirror site OAK.Oakland.Edu and its mirrors):

SimTel/msdos/hamradio/
simptr21.zip    Generic TNC comm program (packet, rtty, etc)

SimpTerm v2.1 is a simple terminal program designed to be used with
almost any tnc or tu on the market.  Features of SimpTerm are:

  o Split window operation.

  o Macro key definitions.

  o User customizable Help screen

  o Most of the non-ascii keys can be used as function keys

  o Optional scroll back feature on the receive window and trans-
    mit windows

  o Simple status display in the middle of the screen

  o Capturing of data to a disk file

  o Access DOS commands without dropping communications
    connection

  o Control of the com port definitions from command line, init
    file and keyboard.

  o Works on 8088 as well as 80486 and everything in-between.

  o Status line

  o Small enough to work well on resource tight platforms, like
    laptops.

  o Selcal functions, limited unattended operation.

  o Times can be in GMT or local time.

  o A station logging function.

  o User selectable color scheme

  o Automatic "cq" operation (or any other repetitive transmission

  o Function keys and control keys can be assigned to a macro
    string, cause a file to be uploaded or call a function within
    the program.

There are loads of programs that are tailored to specific tnc's and
there are dozens of good terminal programs that can control any tnc in a
"dumb" (that's a technical term) manner.  This program is an attempt to
provide the average ham with something in-between.  It has a lot of
features, but not so many as to make use of the program or the tnc
hard.  It requires you to know the commands of your tnc, but also gives
you the flexibility that only direct communications with a tnc can
provide.

Jim Lynch, K4GVO
[e-mail]

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

Date: Fri, 12 Aug 1994 09:51:32 -0400
From: ihnp4.ucsd.edu!dog.ee.lbl.gov!overload.lbl.gov!agate!spool.mu.edu!news.clark.edu!netnews.nwnet.net!raven.alaska.edu!news.acns.nwu.edu!ftpbox!mothost!lmpsbbs!NewsWatcher![e-mail]
Subject: Smallest MultiMode TNC?
To: [e-mail]

In article <[e-mail]>, [e-mail] (Jim
Swenson) wrote:

> Please help me find the smallest multi mode TNC available.  I am provisioning
> a 40' sailboat for a ham friend for a several year cruise. Space is at an
> absolute premium.  He'll be operating exclusively HF through a modified ICOM
> M600 SSB marine transceiver. So 300 baud max is fine.  Required modes include
> Packet, WeFAX, NAVTEX,  RTTY, CW.  PACTOR, G-TOR and SITOR would be cool but
> not mandatory. Cost is a secondary consideration.   The size of most units
> I've looked at are just not acceptable.  Ideally, we need something about the
> size of a new Supra modem (about 1" h by 5"w by 7" deep).  Is there such
> a beast.  I'd appreciate any help.

Although I can't directly answer your query, I'll take the time to point
out something that you must consider: Most commercial/marine HF
transceivers will NOT accept the standard "high" tones 2110/2310 used by
the amateur community due to the required audio rolloffs when operating in
a 2.5 kHz channelized environment.

Check to see if the M600 has a "direct FSK" capability so that you can run
with TTL or RS232 connection to the TNC instead of audio.  That is by far
the preferred method and eliminates problems with AC hum, alternator whine,
or ignition spikes on the interconnecting cables.  If you can't run DFSK,
be ABSOLUTELY sure that the multi-mode unit you purchase offers FSK tones
in the 1200-1800 Hz range or you will have MAJOR problems.

I don't have the CCIR or CCITT list of worldwide standard tones handy, but
I recall 1300/1500 and 1410/1590 both being common.  In any case, you get
the point, especially if your friend's life might depend on this comm gear
at some point.  We all want him back alive, especially if he will be rare
DX during the trip!!

--
Karl Beckman, P.E.                  <     If our English language is so  >
Motorola LMPS.RNSG.Analog Data      <  precise, why do you drive on the  >
(Square waves & round corners)      <  parkway and park on the driveway? >
   Opinions expressed here do not belong to or represent Motorola Inc.
Amateur radio WA8NVW                        NavyMARS NNN0VBH @ NOGBN.NOASI

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

Date: 14 Aug 1994 13:43:24 GMT
From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!swrinde!elroy.jpl.nasa.gov!lll-winken.llnl.gov!noc.near.net!news2.near.net!news.umass.edu!nic.umass.edu!twain.ucs.umass.edu!mwarchut@network.
Subject: TAPR FTP SITE???
To: [e-mail]

Does anyone know the ftp site for TAPR.



--
*---------------------------------------------------*
|  Michael W. Warchut         Voice:  413-545-2036  |
|  Senior Technician          Fax  :  [phone]  |
|  PC Maintenance Lab         I am only 100% right, |
|  University of Mass           50% of the time.    |
*---------------------------------------------------*

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

Date: Sun, 14 Aug 1994 07:15:06 GMT
From: ihnp4.ucsd.edu!agate!library.ucla.edu!news.ucdavis.edu!news![e-mail]
Subject: Widrow-Hoff LMS algorithm for DSP???
To: [e-mail]

In article <[e-mail]> [e-mail] (Allen Hall) writes:

   Hello again everyone,

   I was wondering if you knew anything about the Widrow-Hoff LMS algorithm
   that was used in Sept. 1992 QST's article "Low-Cost Digital Signal
   Processing for the Radio Amateur".  Appearantly the LMS algorithm is nice
   to use to cut out signals that are repetetive when listening to SSB (you
   wouldn't use it for CW- cause all you would hear instead of the morse code
   was a "click" evertime a new tone came buy :)

   Appearantly this algorithm is used in the HumVee's to stop engine noise in
   the cabin.  (I think there are other car companies working with it to
   reduce second-order boom in 4 cylinder cars).

   If you know where I can find this algorithm or further information about
   it, please let me know.

   TNX et 73!
   Allen Hall     [e-mail]

   ps- as always, I look forward to any and all comments that you may have
   concerning this posting.


Details of the LMS algorithm can be found in virtually any
introductory book or paper on adaptive signal processing, e.g.,
_Adaptive Signal Processing_ by Widrow and Stearns or _Adaptive Filter
Theory_ (or something like that) by Simon Haykin.  The basic algorithm
is as follows:

X(k) is an N-element array of input samples at time k.  For a
     transversal filter, the elements of X are samples in a shift
     register.
W(k) is an N-element weight vector (i.e., the filter coefficients)
     at time k.  Ideally, when the adaptive filter converges, W() will
     change slowly or not at all with time.
d(k) is the desired signal at time k.  How this desired signal is
     generated depends on the application.  It can be merely
     correlated with the actual signal.

We define the instantaneous error as e(k) = d(k) - X(k)^T W(k), where
^T denotes matrix transpose.

LMS is a form of the steepest descent algorithm dating back to Cauchy
(or some other famous dead guy), where the gradient of the mean
squared error (MSE) with respect to the weight vector is used adjust
the weights so as to minimize the MSE.

The trick behind the LMS algorithm is to replace the MSE with the
instantaneous squared error in the computation of the gradient.
Skipping the math (which is actually fairly simple), we get

W(k+1) = W(k) + mu e(k) X(k)

Simple as that.  mu is called the adaptation step size.  If it is much
too large, the filter becomes unstable and never converges.  If it is
a bit too large, the MSE will not reach its minimum value.  If it is
too small, the filter will take forever and a day to converge.  A
rough first guess for setting mu for a transversal filter is

mu = 1 / (N * signal power).

Ideally, it should be relatively large at first and then made smaller
when the filter nears convergence.

As you can see, it's a simple algorithm to implement, which is why
it's so popular.  It can be slow to converge, however, depending on
the error surface and the initial weight vector.  Also, because it
never (or almost never) actually reaches the minimum MSE, the LMS name
is not quite acurate; some people prefer "stochastic gradient"
algorithm.  But since it's so simple, it's easy to simulate and play
around with on a computer.  Have fun.

--
Jeff Schenck
[e-mail]
Department of Electrical and Computer Engineering         __o
University of California                                _`\<,_
Davis, CA 95616                                        (_)/ (_)
[phone]                                   ~~~~~~~~~~~~~~~

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

Date: 13 Aug 1994 13:15:57 -0700
From: nntp.crl.com!crl3.crl.com![e-mail]
Subject: Widrow-Hoff LMS algorithm for DSP???
To: [e-mail]

Allen Hall ([e-mail]) wrote:
: Hello again everyone,

: I was wondering if you knew anything about the Widrow-Hoff LMS algorithm
: that was used in Sept. 1992 QST's article "Low-Cost Digital Signal
: Processing for the Radio Amateur".  Appearantly the LMS algorithm is nice
: to use to cut out signals that are repetetive when listening to SSB (you
: wouldn't use it for CW- cause all you would hear instead of the morse code
: was a "click" evertime a new tone came buy :)
: ... etc ...


The Widrow LMS and  Wiener-Hopf are adaptive digital filtering techniques.

The following books have chapters on adaptive digital filters:

1.  Digital Signal Processing - A practical Approach
    Emmanuel C. Ifeachor and Barrie W. Jervis

2.  The TI Digital Signal Processing Applications Series:
    Applications with the TMS320 family, algorithms and implementation
    Vol 1 part number is SPRA012A
    Vol 2 part number is SPRA016
    Vol 3 part number is SPRA017

    This series of books deal exclusivly with the TI DSP processors.  There
    is a lot of practical applications as well as some theory.

    The TI literature number is 1-800-477-8924, all they need is the part
    numbers and your address, the books are free.

--
Henry Smith ([e-mail])

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

Date: Sun, 14 Aug 1994 01:53:33 GMT
From: agate!spool.mu.edu!uwm.edu!news.alpha.net!mvb.saic.com!eskimo![e-mail]
Subject: Windows 3.1 and Baycom Modem TCP/IP networking
To: [e-mail]

Andrew J Lynch ([e-mail]) wrote:

: Packet Radio Folks,

: I have a question regarding Windows 3.1 or WFW and ham/packet radio:  Is
there a Windows or WFW driver available for the Baycom packt radio modem
that would allow TCP/IP networking functions over packet radio?
: I understand that Windows 3.1 or WFW can use TCP/IP networking with the
WINSOCK.DLL.  This provides TCP/IP networking services to an Windows TCP/IP
application.  Whatever networking medium used requires a driver, ie
SLIP/PPP, ethernet, token ring, etc.
: Ham/packet radio also uses TCP/IP as a protocol in local area networks.  I
have a Baycom modem and plan to use the AX.25 driver withthe DOS program
KA9Q NOS to access the local TCP/IP packet network.

: My question is: Is there a way to tie the Baycom modem into Windows 3.1 or
WFW?  You could then use the TCP/IP applications over pacet radio just like
you would over an ethernet or SLIP/PPP, only much slower. I think you would
need a packet driver like the etherne cards require.

: Has anyone got any information on this?  If I get any responses, I will
combine and post to this list.

: THANKS IN ADVANCE!!

: Andrew Lynch, N8VEM
: [e-mail]

: 73!!

You're probably not going to have a lot of luck doing this with Windows and
the Baycom.  The Baycom product requires a lot of the computer's attention,
because it has to 'bit-bang' data into and out of the serial port.  It can't
take advantage of the parallel-to-serial/serial-to-parallel conversion
capabilities of the serial port, and therefor is very processor-intensive.
This along with Windows being intensive and trying to multi-task is not a
good combination.  There are folks who are working on writing a packet
driver to go between Windows TCP/IP applications (Winsock or FTP's PACKET
driver interface) and a KISS-capable TNC.  But I don't think you're going to
see it for Baycom-type modems.

Think of it this way - Most Windows systems have trouble keeping up with
19200 baud with only one task open when you don't use a buffered UART.  All
the application has to do is get the interupt, read the port, clear the
port, then display (or process) the byte received.  At 19200 baud this
happens at 1920 times per second or slower, and you have until the next
charachter has arrived to read the currently stored character before you
will lose data.  Also, typically the most intensive processing that has to
be done on a character-by-character basis is CRC calculations.  When sending
characters, all the program has to do is respond to keyboard interupts (if
typing), send bytes to the com port, and wait for an interupt from the com
port that says it's ready for another byte, and perhaps update CRC
calculation.

With Baycom, assuming the software is set up to use one of the PC's timers
(the lowest processor overhead), at 1200 bauds, when the interupt comes in,
you have to go read the timer, reset the timer, decide how many bit times
have passed since the last interupt, stuff and shuffle the proper number of
bits into the shift register, account for 'bit stuffing', then see if you've
filled a byte.  If so, the byte goes into the packet buffer, and if you have
time, maybe you update the CRC calculation for the packet.  This can happen
in one bit-time (1/1200th of a second, more or less, depending on signal
'twist' and modem timing errors).  And all that processing has to be
finished before the next interupt.  Then when a packet is complete and
error-free, the driver still has to check addressing, etc.  all of this is
>before< the packet gets passed up to the TCP/IP software stack.  And the
driver has to continue handling interupts and dealing with the incoming data
stream, trying to make sense of it accurately, until the data stream stops -
usually when the squelch on the radio closes.  And during all this, Windows
is supposed to find time for other applications to run.  Not a problem that
will be easily solved.

73,

Bob

--
---------------------------------------------------------------------------
Bob Donnell, kd7nm     [e-mail]   [e-mail]
Western Washington Amateur IP Address Coordinator   [phone]
---------------------------------------------------------------------------

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

End of Ham-Digital Digest V94 #272
******************************