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DVP is no more?

Subject: DVP is no more?
From: Waltk@PICA.ARMY.MIL (Waltk@PICA.ARMY.MIL)
Date: Mon Aug 29 11:29:42 1994
In light of what we've heard about support for the DVP,
I'm glad I went the Sound Blaster route when I decided on
a voice keyer.  You can get a SB Pro card for about $60, new.
For another 25 bux, get the Voice Blaster software sold by LTA
and you a DVP.  Spend a few bux on a box, connectors and a xfrmr,
all available R/S and you're set. Then use free/share/ware programs 
to manually edit, compress, and equalize the voice files you create 
with the SB Pro. Add a little RF compression from the rig and you 
have one heck of a signal, guarenteed to break the toughest of 
pileups.

>From DFREY" <HARRIS.DFREY@IC1D.HARRIS.COM  Mon Aug 29 15:44:09 1994
From: DFREY" <HARRIS.DFREY@IC1D.HARRIS.COM (DFREY)
Subject: Open Wire for Low Loss ?
Message-ID: <QCY2.DFREY.6693.1994 0829 0944 0944>


_____________________________ Forward Header __________________________________
Subject: Re: Open Wire for Low Loss ?
Author:  HARRIS.W5ROBERT at Harris

Richard,  what is the best way for me to feed 300-ohm line
with my rig???   what's the "transformer"?
--
73  Robert Wood WB5CRG

Bob,

That is the original open ended question.  I would ask first:
What is your load?  If the load is reasonablly flat, ie a low swr
- close to 300 ohms and balanced at the far end, then almost
anything will work.

Amoung the appropriate devices:
1. 4:1 torroidal or rod type balun to 75 ohm coax or transmatch
   to 50 ohms,
2. a balanced input transmatch - like the old Johnson Matchbox.
3. an isolated/insulated unbalanced transmatch with a 4:1 balun
   on the transmitter side.

As the load becomes less well defined, like a random antenna for
instance, then you cannot use broadband matching devices.  #2 and #3
are better.

I use #3.  An L network in a wooden box with a 3 wire 1:1 balun on the
transmitter side. This works very well for any terminating impedance,
though some purists may cringe.  Misapplication of baluns is the major
contributor to their poor reputation.

If you are thinking of the latest thread on ladder line for long runs
instead of hardline, your load is controlled. A 9:1 balun and 450 ohm
line are OK.

Dick     k4xu           dfrey@harris.com



>From Peter G. Smith" <n4zr@netcom.com  Mon Aug 29 16:23:09 1994
From: Peter G. Smith" <n4zr@netcom.com (Peter G. Smith)
Subject: DVP
Message-ID: <Pine.3.89.9408290837.A15175-0100000@netcom>

Sounds as if there are at least two a lternatives to the DVP.

73, Pete                                       
N4ZR@netcom.com

On Sun, 28 Aug 1994, Bruce Herrick wrote:

> Yes, it [the Contest Card] only stores 16 seconds.  However, I have yet to 
find a need to store
> any more than that.  However, since your mileage may vary, you should
> contact Gary, W9XT (ppvvpp@mixcom.com).  The manufacturers of the chip that
> stores the voice have a new, 60 second part available, and Gary has it
> working in the Contest Card.  It is still limited to 4 message segments, but
> even that can be modified with a little work.  Talk to Gary.
> 
> Hope this helps.
> 
> 73, Bruce WW1M
> 
> -- 
> Bruce D. Herrick               bdh@mixcom.com      Home:   414.462.1270
> Pryon Corporation                                  Office: 414.253.5678
> N93 W14575 Whittaker Way                           Fax:    414.253.2772
> Menomonee Falls, WI  53051                         PacketCluster: WW1M > NB9C
> 

>From Peter G. Smith" <n4zr@netcom.com  Mon Aug 29 16:29:54 1994
From: Peter G. Smith" <n4zr@netcom.com (Peter G. Smith)
Subject: DVP is no more?
Message-ID: <Pine.3.89.9408290855.A15175-0100000@netcom>

Yes, indeed.  The only thing missing is the wonderful Harvard Radio 
cables that were supplied with the DVP, which appear to be very top 
quality - one of these days I may be running power and need them.  
Anyhow, I wonder (Ken, are you reading the mail?) whether the DVP 
uses/used any particular commercial standard for its sound 
recording/playback.  It would be interesting to know whether any of the 
available shareware could be used to manipulate voice files as Walt suggests.

73, Pete                                       
N4ZR@netcom.com

On Mon, 29 Aug 1994 Waltk@PICA.ARMY.MIL wrote:

> In light of what we've heard about support for the DVP,
> I'm glad I went the Sound Blaster route when I decided on
> a voice keyer.  You can get a SB Pro card for about $60, new.
> For another 25 bux, get the Voice Blaster software sold by LTA
> and you a DVP.  Spend a few bux on a box, connectors and a xfrmr,
> all available R/S and you're set. Then use free/share/ware programs 
> to manually edit, compress, and equalize the voice files you create 
> with the SB Pro. Add a little RF compression from the rig and you 
> have one heck of a signal, guarenteed to break the toughest of 
> pileups.
> 

>From modular!liddy!eric@cs.arizona.edu (Eric Gustafson)  Mon Aug 29 16:20:00 
>1994
From: modular!liddy!eric@cs.arizona.edu (Eric Gustafson) (Eric Gustafson)
Subject: No subject
Message-ID: <m0qf8VZ-00009WC@liddy>

To: arizona!canada.unbc.edu!lyndon
CC: cq-contest@tgv.com
In-reply-to: <Pine.3.89.9408261940.B29593-0100000@canada.unbc.edu> 
(arizona!canada.unbc.edu!lyndon)
Subject: Re: Antenna modelling software


Lyndon,

Here is the info I have on NEC antenna modeling software availability.


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


You can obtain NEC2 (the real thing, "industrial strength") via anonymous
ftp from:
                ftp.netcom.com in /pub/rander/NEC

There is both source code and executables for Sun, IBM RS, Macintosh, and
DOS based PC's. You will also find several NEC related utility programs
there also.



The following NEC related files are available via anonymous FTP on 
netcom.com in /pub/rander/NEC

---------------------------------------------------------------------
NEC (Numerical Electromagnetic Code):


All files with .Z prefix compressed with UNIX compress

NEC2_Mac_.hqx.Z
                NEC2 executable for the Macintosh (in compressed .hqx format)
                from Barry Newberger (bsn@fusion.ph.utexas.edu)

NEC2_Mac_README.txt
                Document file for Mac version of  NEC2


nec2.sun4.dl.Z 
                SUN4 executable (dynamically linked) of NEC2
                compiled for 1000 segments
                from Weston Beal (weston@arrakis.ebay.sun.com)


nc2s1500.sun4.Z
                SUN4 executable (statically linked) of NEC2
                compiled for 1500 segments
                from John Boyer (john.boyer@rd.eng.bbc.co.uk)


nec2.rs6000.Z   
                IBM RS/6000 executable of NEC2. Runs under AIX 3.2
                from Doug Braun (dbraun@iil.intel.com)

nec2.rs6000_readme.txt
                Document file for RS/6000 version of NEC2

mininec3.zip    
                BASIC source code and DOS executable for mininec3 from NOSC

nec2_src.tar.Z  
                Fortran source code for NEC2

nec_param_util.Z  
                  Perl script to create NEC input files from parameterized
                  physical descriptions.
                  from  Doug Braun (dbraun@iil.intel.com) 

nec_post_processor.Z
                Creates polar plots from NEC output.
                MS Quick Basic source code.
                from John Boyer (john.boyer@rd.eng.bbc.co.uk)

nec3.tar.Z
                Fortran 77 source code for nec-81. (modified for 3000
                segments) (from Petri Kotilainen OH3MCK)


readme.nec3
                Readme file for nec3.


necdraw.zip
                DOS utility for verifying correctness of NEC models. Checks
                adherance to rules and provides 3-D display of model. (from
                ACES archive) 

nec_hist.txt
                Article from ACES newletter outlining the history of the
                various versions of NEC.


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


73,  Eric  N7CL

------------------------------------------------------------------------------
Eric Gustafson  N7CL                  | The mountains are high and the Emperor
6730 S. Old Spanish Trail             | is far away.
Tucson, AZ 85747                      |
INTERNET: modular!eric@cs.arizona.edu | You can't work 'em
     CI$: 71750,2133                  | if you can't hear 'em.
------------------------------------------------------------------------------

>From Balmforth, Kevin D" <kbalmforth@msmail2.hac.com  Mon Aug 29 19:28:20 1994
From: Balmforth, Kevin D" <kbalmforth@msmail2.hac.com (Balmforth, Kevin D)
Subject: PIN diode reference
Message-ID: <9408291726.AA14659@igate1.hac.com>

In this month's QST, there was some mention by WB2WIK on use of PIN diodes
(vs relays) to switch HF amps.  Does anybody have a reference on practical
circuits for PIN diode switching of high power amps?  Thanks - Kevin NC6U 

>From Steve Harrison <sharriso@sysplan.com>  Mon Aug 29 19:17:07 1994
From: Steve Harrison <sharriso@sysplan.com> (Steve Harrison)
Subject: Worked All CA Counties/CQP
Message-ID: <Pine.3.87.9408291407.C5150-0100000@eagle>



On Sun, 28 Aug 1994 zf8bs@twg.com wrote:
> For anybody who might have missed the original announcement, here's a 
> repeat.  We did manage to get this run in the September QST (even though 
> this "family" journal managed to edit out all references to our decadent
> practice of giving wine to the winners).  Note also the T-shirt award;
> that didn't make it either.  And nothing made it into CQ, despite our
> best efforts.
>  
The reason the prizes were not mentioned in QST is because of US Postal 
Service regulations regarding non-profit organization mailing rates. To 
maintain their non-profit status, such organizations cannot allow the mention
of prizes in materials mailed at the non-profit rate. I'm not certain, 
but I suspect the regulations probably say something about "tangible" 
prizes, which would explain why the awarding of certificates to contest 
participants is OK.
 
Apparently, it is too much hassle to prove to the Postal Service that the 
prizes are actually EARNED rather than won in games of chance (now, don't 
start giving me flames about contests not being chancy endeavors for most 
of us!). This regulation also applies to your local club if they are 
mailing the newsletter using non-profit organization rates; mention of 
door or hamfest prizes are a no-no and the Postal Service WILL take away 
your non-profit mailing rate privilege if they see such announcements. 
73, Steve KO0U/4



>From Peter G. Smith" <n4zr@netcom.com  Mon Aug 29 21:37:16 1994
From: Peter G. Smith" <n4zr@netcom.com (Peter G. Smith)
Subject: ICE
Message-ID: <Pine.3.89.9408291317.A10045-0100000@netcom>

Seversal respondents to the lightning post have referred to ICE as a less 
expensive alternative to Polyphaser.  Can anyone provide a phone or fax 
number for them?  A quick scan of recent QST and CQ gave me no clues.

73, Pete                                       
N4ZR@netcom.com


>From Steve Fraasch <sfraasch@ATK.COM>  Tue Aug 30 00:21:00 1994
From: Steve Fraasch <sfraasch@ATK.COM> (Steve Fraasch)
Subject: PIN Diode Reference
Message-ID: <2E626E98@msm.ATK.COM>


Kevin, NC6U asks:
"In this month's QST, there was some mention by WB2WIK on use of PIN diodes
(vs relays) to switch HF amps.  Does anybody have a reference on practical
circuits for PIN diode switching of high power amps?"

Kevin, the most usual reference I have found is the "PIN Diode Designer's 
Handbook and Catalog," by Unitrode, Lexingon, MA, a PIN diode manufacturer. 
 You can design your own circuits using it, or use the existing designs in 
the "Applications" section.  The book covers the basics: power handling, 
bias, isolation, etc.  Of course, all of the Unitrode diodes are listed, but 
the info is transferable to other diodes.  I would call a Unitrode rep in 
your area to obtain a copy.  The domestic rep in CA is listed as: "Centaur 
Corp," in Irvine, San Diego, and Woodland Hills.

Ham Radio magazine had numerous articles using PINs, but you would need to 
search bibliography of amplifier articles in the mid-80s to find them.  I 
will let you know what I have at home for reference.

73, Steve Fraasch

sfraasch@atk.com

>From Doug Grant <0006008716@mcimail.com>  Tue Aug 30 02:29:00 1994
From: Doug Grant <0006008716@mcimail.com> (Doug Grant)
Subject: DVP Sample rates
Message-ID: <41940830012914/0006008716NA5EM@mcimail.com>

A bit of the history of the DVP...

When Ken was beginning development of the DVP, he sought advice on the 
resolution and sample rates for the audio conversion. He had several
constraints:

1. Components must be readily available from multiple sources, so a small
manufacturer like Harvard Radio (a software house, remember!) could get
parts.

2. The sound quality must be better than telephone toll-quality.

3. It's gotta be ready for Dayton.

Price was a minor issue - the early adopters who had tens of thousands
invested in their stations were unlikely to quibble about a $200 increment.

I told Ken he ought to consider the Soundblaster formats, but he figured he'd
have a lot of trouble licensing the DOS drivers, etc.

I told him I knew of a 'Soundblaster-on-a-chip" in development at an IC company
that happens to print my paycheck, but that it wouldn't be available until
well after Dayton.

I suggested multiple-sourced A/D and D/A converters, which he had no problem 
procuring, and further suggested 12-bit linear resolution as a compromise
between low-quality 8-bit speech and then-too-expensive 16-bit quality. 

A sample rate of 10 kSPS was chosen as a reasonable compromise of audio
bandwidth and anti-aliasing filter requirements.

Ken insisted on using relays to bypass the DVP when not in use, as well as
first-class cable assemblies with the grounding done *right*, so people
would be happy with the board and not call him endlessly to debug ground
loops.

Yup - the DVP is expensive and overdesigned, compared to the dirt-cheap
Soundblaster-type stuff available now. However, it works fine and you don't
have to monkey with it to get it to work.

And now you know why certain choices were made.

73,
Doug  K1DG

k1dg@mcimail.com

>From Fred Hopengarten" <k1vr@k1vr.jjm.com  Mon Aug 29 03:09:32 1994
From: Fred Hopengarten" <k1vr@k1vr.jjm.com (Fred Hopengarten)
Subject: TH7 Problem
Message-ID: <2e614364.k1vr@k1vr.jjm.com>

On Sun, 28 Aug 94 22:52:00 GMT, "Barry Kutner" <barry@w2up.wells.com> wrote:
> Recently noticed that the resonance point on 10 meters moved way up the
> band. SWR at 28.0 about 3.5:1, down to about 2:1 from 28.5 - 29.0,
> and 1.5:1 at 29.2, then goes back up.
> No problems on 15 or 20. Any thoughts appreciated. Tnx de Barry
Take it down.  Using compressed air, blow out the ten meter
traps in the front driven element.  I'll bet a LOT of
vegetable matter blows out.

While you are at it, perform the K6LRN mod, and extend RDE-2
and FDE-2 1.5" on each side of the boom.  This will enhance
performance all over 15 and 20, as well as lowering SWR in
CW section of 10.

That's the best that AA1AA and I can think of (as we were
putting a TH7 up today and happen to have the manual still
open).
-- 
                      Fred Hopengarten K1VR
           Six Willarch Road * Lincoln, MA 01773-5105
     home + office telephone:  617/259-0088 (FAX on demand)
                   internet:  k1vr@k1vr.jjm.com
"Big antennas, high in the sky, are better than small ones, low."

>From Robert A. Wilson" <n6tv@VNET.IBM.COM  Tue Aug 30 04:50:05 1994
From: Robert A. Wilson" <n6tv@VNET.IBM.COM (Robert A. Wilson)
Subject: Wireman Braided Copperweld Rust Problem -- now fixed

K3NA writes:

> By the way, W3LPL installed antennas last year with copperweld
> "Flexweave", sold through The Wireman.  Flexweave is a braided cable
> where the strands are small-diameter copperweld wires.  After less
> than one year in the air in a normal rural environment, the wires had
> completed rusted!!!  Apparently the braiding process was so damaging
> to the cable that virtually every strand was nicked in many many
> places.  The steel rust, when it galls (expands outward), sheds the
> copper layer.  The result:  many wire antennas made of rusty steel
> wire -- all in the near fields of W3LPL's many yagi's!  It all had to
> be thrown away.

I checked with N6BT who uses some of this wire in the Force 12 antenna
line.  Tom says The Wireman changed the manufacturing process when
they found out there was a problem.  The wire is now made in a way
that does not damage the copper, and the copper is also tinned.  Tom
has not heard of any problems using this wire since they made this
change.

>From Wirzenius Jari <HATJWI@HATMAIL.HATFI1.msgw.kone.com>  Tue Aug 30 16:32:00 
>1994
From: Wirzenius Jari <HATJWI@HATMAIL.HATFI1.msgw.kone.com> (Wirzenius Jari)
Subject: N4KG tower feed system
Message-ID: <2E635168@msgw.kone.com>


As soon as I read the article I made a decision to give it a try. I fed the 
the tower as described by N4KG QST article and did the match with a 4:1 one 
balun.

So far I have got good results with it. My 160 meter inverted dipole which 
feed point is only at 15 meters above ground is mostly 3 s units weaker in 
listening any stations at a distance of less than 2000 km. I made the 
antenna last friday so I have not got much experience with real DX. I can 
work easily UA9, but I can do it with the dipole too. I will let you know 
when I got time to check the antenna with real far distance DX. The start 
looks promising.

I have 10 meters of sloping wire to extend the length of my tower hanging 
down just below my two yagis Cuscraft A3 and home made 18 MHz 3 element 
yagi. They are three meters apart. The tower is 21 meters high and the pipe 
holding the yagi extends three meters above the top of tower. THe radials 
were made of insulated hard copper wire and they were 41 meters long and I 
have now only four of them, but I have plans to add more radials. The 
feedpoint is at 5 meters, so it is a little higher than in the article, but 
the length calculations by the area of the yagi matched in my case 
perfectly. As the two yagis are fairly close to each other I thought that 
the two must be added together. The best SWR hits on 1830 and the SWR 1.3:1 
and the width is quit large. I don't have my notes in office and I can't 
remember them excatly.


73's
Jari, OH2BVE

jari.wirzenius@hat-fi.kone.com

>From Peter G. Smith" <n4zr@netcom.com  Tue Aug 30 11:40:24 1994
From: Peter G. Smith" <n4zr@netcom.com (Peter G. Smith)
Subject: ICE Telno Thanks
Message-ID: <Pine.3.89.9408300342.A5034-0100000@netcom13>

Thanks to everyone who provided phone numbers and testimonials for ICE.  

73, Pete                                       
N4ZR@netcom.com


>From DAVID ROBBINS KY1H W-413-494-6955 H-413-655-2714 
>ROBBINS@GUID2.DNET.GE.COM <robbins@guid2.dnet.ge.com>  Tue Aug 30 12:08:17 1994
From: DAVID ROBBINS KY1H W-413-494-6955 H-413-655-2714 
ROBBINS@GUID2.DNET.GE.COM <robbins@guid2.dnet.ge.com> (DAVID ROBBINS KY1H 
W-413-494-6955 H-413-655-2714 ROBBINS@GUID2.DNET.GE.COM 
<robbins@guid2.dnet.ge.com>)
Subject: braided wire
Message-ID: <9408301103.AA20152@thomas.ge.com>

>>K3NA writes:
>>
>> By the way, W3LPL installed antennas last year with copperweld
>> "Flexweave", sold through The Wireman.  Flexweave is a braided cable
>> where the strands are small-diameter copperweld wires.  After less
>> than one year in the air in a normal rural environment, the wires had
>> completed rusted!!!  Apparently the braiding process was so damaging
>> to the cable that virtually every strand was nicked in many many
>> places.  The steel rust, when it galls (expands outward), sheds the
>> copper layer.  The result:  many wire antennas made of rusty steel
>> wire -- all in the near fields of W3LPL's many yagi's!  It all had to
>> be thrown away.
>
>n6tv responded
>
>I checked with N6BT who uses some of this wire in the Force 12 antenna
>line.  Tom says The Wireman changed the manufacturing process when
>they found out there was a problem.  The wire is now made in a way
>that does not damage the copper, and the copper is also tinned.  Tom
>has not heard of any problems using this wire since they made this
>change.

but if the wire is tinned doesn't that kind of defeat the purpose of using
copper to start with?  Since most of the current flows on the surface and
now the surface is lead/tin instead of copper how does the loss compare
to plain copper?  is tinning better than galvanized steel?

73, Dave KY1H  Robbins@guid2.dnet.ge.com


>From fish@crl.com (Bill Fisher, KM9P  Concentric Systems, Inc.)  Tue Aug 30 
>16:11:23 1994
From: fish@crl.com (Bill Fisher, KM9P  Concentric Systems, Inc.) (Bill Fisher, 
KM9P  Concentric Systems, Inc.)
Subject: K4VX guy wire article
Message-ID: <199408301511.AA00721@mail.crl.com>

You probably all saw the article by Lew Gordon in QST that basically said
you don't need to break up guy wires.  This was according to some NEC
modeling that Lew had done.

Well... Being one that doesn't believe everything a computer spits out, I
have a question.  I would like to hear from ANYONE that has put up any kind
of antenna on a tower with NON-INSULATED guys and experienced problems, that
were eventually fixed by breaking up the guys.

On my tall tower that will support 80 & 160 antennas, I will be using
phyllistran (sp?).  My application of the non-broken guys will be on a
couple of towers that will only support 10, 15 & 20 meter yagis.  These
towers will only be 30 - 40 feet tall.  (Being on a hill sure is nice for
saving on tower sections!  The cement company said they couldn't get a truck
up there though.  Ouch.)

Thanks for all of the help on my radials question.  I think a couple of guys
are putting too much faith in their computers & software.  N0BIW sent me an
article from the Low Band Monitor from July 1994.  It was put together by
K0CS.  Basically he tested different radial schemes with a field strength
meter in the near and far fields.  Results were that elevated is best.  The
difference between two and four radials is minimal if at all in the far
field.  This article is definately worth reading if you are messing with
this stuff.

73
  
---
Bill Fisher, KM9P
Concentric Systems, Inc.  (CSI)
404-442-5821  Fax 404-667-1975


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