contestless in San Antonio
Nd3f at aol.com
Nd3f at aol.com
Fri Aug 18 08:30:16 EDT 1995
Looks like I'm gonna be here in sunny San Antonio for awhile.
Any contesters wanna do a multi-single for NAQP phone?
Any good contest club meetings or hamfests in the next few weeks?
Anybody need help w/ an antenna party?
Anybody wanna rove for Sept VHF?
If yes to any, call me at 210 522-0249 work
or 210 647-0041 room 204 non-work
Brian, ND3F
>From Lau, Zack, KH6CP" <zlau at arrl.org Fri Aug 18 13:24:00 1995
From: Lau, Zack, KH6CP" <zlau at arrl.org (Lau, Zack, KH6CP)
Date: Fri, 18 Aug 95 08:24:00 EDT
Subject: DC receivers
Message-ID: <30348746 at arrl.org>
They have some significant advantages compared to other approaches.
1) Perhaps the highest dynamic range of any currently practical approach.
This is useful for those trying to listen while transmitting--on the same
band....
(Actually, my experience comes from operating within a few hundred feet
of big stations and trying to share bands)
2) Very good operating characteristics when optimized for CW operation.
Suppose you like a 300 Hz CW note. Opposite sideband suppression
isn't a function of the offset from carrier, like filter radios. Thus, you
get
the same suppression whether you choose 300 Hz or 3 kHz. You can
also tune the supression for a maximum at your favorite frequency, so the
image "drops out" as you tune for the right pitch.
3) Is good AGC impossible? Of course not. If you are really serious
you could build a separate, tracking receivers just for the purposes of
AGC and noise blanking. These don't have to be DC receivers like
the main information channel.
However, there is one huge disadvantage. Designing one that works
well is no trivial task, though it may appear to be simple on the surface.
Multiple conversion radios are much better suited for casual, consumer
grade applications where performance must be sacrificed to be price
competitive. Anyone doubting this statement might ask why contesters find
it necessary to improve the filtering on stock radios...
Zack KH6CP/1
>From Joe Subich" <subich at ramlink.net Thu Aug 17 18:44:21 1995
From: Joe Subich" <subich at ramlink.net (Joe Subich)
Date: Thu, 17 Aug 95 23:44:21 +0600
Subject: MultiTasking on OS/2
Message-ID: <9508180401.AA0136 at localhost>
KI6VY Writes:
> On a 486SLC2-50 with 8MB of RAM, performance is crisp when DXBase is the only
> active program Actively running ProComm in another DOS session to a 14400 bps
> modem makes the packet alerts in DXBase beep erratically (instead of a clean
> "whoop whoop", you hear distinct stairstepping of the tone frequencies and
> step width varies), but neither program loses any data with the modem, TNC,
> radio or database. Running Word for Windows adds to the sluggish/erratic
> behavior, but still no data loss. Pushing an idle Word session into the
> background restores DXBase responsiveness.
OS/2 performance is heavily memory dependent. If you increase the memory in
the 486SLC2-50 to 16 MB you will find that the DOS multitasking performace is
essentially the same as the 486DX2/66. This can be corroborated by the performace
improvement noted when putting the idle Windows session (Word for Windows) into
the background (OS/2 will essentailly swap out the entire windows session).
> One caveat with OS/2 and 4 serial ports: due to the way interrupts work on the
> ISA bus, each port MUST have a different interrupt (I use 3, 4, 10 and 12 for
> my serial ports) or be a multiport board and driver designed for on-board
> sharing.
There are several ISA multi port serial boards available today that do the proper
IRQ sharing at reasonable prices. In addition Ray Gwinn (AA4VT) has produced an
excellent shareware serial driver (SIO version 1.53) which supports the shared IRQ
serial communication.
With a little effort, less effort than building a competetive contest station, OS/2
provides a bullet proof platform for multitasking DOS applications. It's a real shame
that the developers of contest/DX software haven't seen fit to produce native OS/2
versions ... a properly tuned and working OS/2 system is much more capable and
reliable than any Windows 3.1 or Windows95 system.
... Joe Subich, AD8I
(subich at ramlink.net)
>From km9p at is.net (Bill Fisher, KM9P Concentric Systems, Inc.) Fri Aug 18 13:35:29 1995
From: km9p at is.net (Bill Fisher, KM9P Concentric Systems, Inc.) (Bill Fisher, KM9P Concentric Systems, Inc.)
Date: Fri, 18 Aug 1995 08:35:29 -0400
Subject: Beverages & Irregular Terrain
Message-ID: <199508181235.IAA25256 at mail1.is.net>
>From the desk of W3LPL
>
>Local terrain irregularity will degrade (certainly not improve!)
>the sidelobe performance of a Beverage! Sloped but otherwise regular
>terrain is probably not too bad... (the slope should reduces the angle of
>radiation by the slope angle). But if u have no choice but to place ur
>Beverage over irregular terrain, do the best u can!
I will be experimenting with beverages over extremely irregular terrain this
winter. The beverages to Europe will be going, sort of, down and on the
side of a major drop off. I'm worried about this one.
However, Neal (AE6E), told me that at N6DX they have had very good luck with
beverages running in small valleys that run down hills. Water ways if you
will. He told me to run them down the hill and terminate them at the bottom
before the land starts to rise again. (That's > 1500' in my case) He said
the F/B and F/S should be excellent because of the hill behind the beverage.
Is anyone else using beverages over irregular terrain that can pass on some
tips?
Thanks
Bill
---
Bill Fisher, KM9P - Concentric Systems, Inc.
>From Ed Miske <MISKE at A1.ISD.UPMC.EDU> Fri Aug 18 17:54:00 1995
From: Ed Miske <MISKE at A1.ISD.UPMC.EDU> (Ed Miske)
Date: Fri, 18 Aug 1995 12:54:00 -0400 (EDT)
Subject: Correct "signing" procedure for recent upgrade to General
Message-ID: <D138ZVXCD3HO1*/R=EDISON/R=A1/U=MISKE/@MHS.ISD.UPMC.EDU>
Hi all. Just joined this reflector a few days ago. Have enjoyed reading
all the stuff, particularly the "new rig/DSP filtering" messages.
My Question: Must a recent upgrade to general sign /AG? We are going to
have such a station, KB3BGN, on our NAQP team this weekend. I thought
it was an FCC rule that a station must sing /AG, /AA, /AE until he/she
receives the new license. However, I also remember many operators
insisting, several years back when my good pal N3IXR and I were working
field day using N3IXR/AE, that the /AE was not necessary. Anyone know
fer sure? Is this one of those rules that everyone ignores, such as in
"no harm, no foul"?
Thanks for any help/comments.
(Kinda feel like I just worked my first DX)
73, Ed, N3BGV
>From broz at csn.net (John Brosnahan) Fri Aug 18 14:17:53 1995
From: broz at csn.net (John Brosnahan) (John Brosnahan)
Date: Fri, 18 Aug 1995 07:17:53 -0600
Subject: Need centered world map kiddi at marel.is (Kristinn Andersen)
Message-ID: <199508181317.HAA28785 at uucp-1.csn.net>
>I need one of those maps that has my QTH in the center and shows=
propagation
>directions as straight lines - the one where Australia ends up encircling
>the earth and beyond that you fall off into the black hole!! Sorry, but I
>don=B4t recall what the proper term is (...centric something?).
>Thanks and 73 de Kristinn, TF3KX (kiddi at marel.is)
Kristinn,
You need a program to generate an Azimuthal Equidistant Projection centered
on your QTH. There is an excellent one written by NA3T and NV3Z that is
called azproj10 available as azproj10.zip from
nic.funet.fi/pub/ham/antennas
It requires doing some editing in the postscript language but it is well
commented and easy to do. You will also need a postscript printer or
ghostscript which should be available from the same site.
73 John W0UN
John Brosnahan W0UN
La Salle Research Corp 24115 WCR 40 La Salle, CO 80645 USA
>From Brian McGinness <CARL02 at MACCVM.CORP.MOT.COM> Fri Aug 18 14:49:44 1995
From: Brian McGinness <CARL02 at MACCVM.CORP.MOT.COM> (Brian McGinness)
Date: 18 Aug 1995 08:49:44 -0500
Subject: MultiTasking
Message-ID: <"CARL02 95/08/18 13:49:44.505076"@MACCVM.CORP.MOT.COM>
I agree with you Pat (NZ4K)! OS/2 Warp is a significant
improvement if your machine can handle it. I have utilited
it to run PcPakratt for Windows and CT at the same time
(in preparation for the upcoming RTTY CONTEST) and it works
just fine.
I also use it to access the Internet, it has a FB Web browser
and other internet tools in the Bonus Pak, as well as fax modem
support etc.
Not for the light-hearted as you mention, but when you get it all
working; CD-ROM, Fax Modem, Sound Card, Internet support, etc
it is quite awesome!
73, Brian
WA3WJD
carl02 at maccvm.corp.mot.com
>From richard.frey at Harris.COM (DFREY) Fri Aug 18 14:10:55 1995
From: richard.frey at Harris.COM (DFREY) (DFREY)
Date: Fri, 18 Aug 1995 09:10:55 -0400
Subject: DSP and AGC
Message-ID: <034a43d0 at maila.harris.com>
>73 de Mario, S56A, N1YU.
>P.S. How many filter taps one needs for >100 dB rejection of decent
>analog filter? Is the time delay acceptable in real life?
My commercial experience with DSP filtering and AGC loops indicates
that the more processing you put in front of the AGC detector, the
longer it takes to calculate. This processing delay becomes an attack
delay in the AGC loop and can result in a significant POP especially
when using QSK.
Users of the Ten-Tec Omni A/B/D will remember this effect.
Dick 9A/K4XU
>From Ronald D. Rossi" <rrossi at VNET.IBM.COM Fri Aug 18 15:32:47 1995
From: Ronald D. Rossi" <rrossi at VNET.IBM.COM (Ronald D. Rossi)
Date: Fri, 18 Aug 95 10:32:47 EDT
Subject: MultiTasking
Ref: Note from aa4lr AT radio.org (attached)
>>Hi Guys...
>>
>>I have resisted Windows but notice that most new software seems to use it..
>>Whattaya do??????
>
>You avoid Microsoft-domination by doing what I did years ago. You buy a Mac....>
>
>(sorry, couldn't resist....)
>
>Bill Coleman, AA4LR Mail: aa4lr at radio.org
>Quote: "The same light shines on vineyards that makes deserts." -- Steve >
>Hackett
OS/2 Warp does windows and can multitask quite nicely. I will let you
know how it works on my CONTEST computer in a few weeks.
(SICR (tm))
73 de N1PBT...Ron (rrossi at vnet.ibm.com) ><>
>From Ronald D. Rossi" <rrossi at VNET.IBM.COM Fri Aug 18 16:06:38 1995
From: Ronald D. Rossi" <rrossi at VNET.IBM.COM (Ronald D. Rossi)
Date: Fri, 18 Aug 95 11:06:38 EDT
Subject: NAQP Team...
Boy I just don't know where I misplaced the address to send a team
roster for NAQP this weekend...hows about a reminder for the brain
dead like me?
TEAM: Big Blue (small score)
N1PBT, Ron Rossi
WA1PRY, Lloyd Walls
WQ5G, Steve Runyon
WA2IBM/6, Bill Walters
There is an open slot for another IBMer!!!
73 de N1PBT...Ron (rrossi at vnet.ibm.com) ><>
>From n2ic at drmail.dr.att.com (LondonSM) Fri Aug 18 15:44:42 1995
From: n2ic at drmail.dr.att.com (LondonSM) (LondonSM)
Date: Fri, 18 Aug 1995 08:44:42 -0600
Subject: Beverages
Message-ID: <9508180844.ZM6717 at dr.att.com>
After reading W3LPL's comments on beverages, I thought I would contribute my 2
cents, as well as ask a question ....
Last year was my first experience with my own beverages. By the end of the
contest season, I had 5 600 foot beverages, all 3 feet off the ground (no deer
problems here, but the neighbors escaped Bovine were a different story !), all
made using #14 steel electric fence wire. They were oriented NE, E, SE, SW and
NW. The directional characteristics were such that neither the NE nor SE
beverages worked towards Africa, requiring the use of the E beverage. I used a
9:1 transformer, with no preamp. I had absolutely no problems with inefficiency
due to the low height - plenty of signal for my TS-940S on both 80 and 160
meters. For supports, I used 3 foot steel electric fence posts, and plastic
electric fence insulators (available at your local horse/farm supply store for
< $1.00 per post/insulator). At a height of 3 feet, any sag in the beverages
could become critical, so lots of tension is required, along with supports
every 70-100 feet. Each beverage was terminated with a 350 ohm resistor, to a 4
foot ground rod. I did not use a sloping termination, figuring that the signal
pickup on a 3 foot vertical downlead was small. If the 350 ohm terminating
resistor opened (which happened several times during the winter, for various
reasons), it was obvious that the beverage was not performing well. The
difference between a terminated and unterminated beverage is astounding. I
don't think an unterminated beverage is worth the effort.
Now, the down side and question....
AA0RS (a.k.a. G3SZA) lives about 10 miles east of me. He also had a set of
beverages of comparable length, but about 10 feet high. He used sloping
terminations. In addition, he used ground radials at the termination. The
performance of his beverages was slightly better than mine on 160 meters, in
terms of S/N. Enough of a difference that he worked several mults in ARRL
Phone that could not be heard at the same time at my QTH. Was it the height ?
The termination radials ? His copper wire vs. my steel wire ?
Steve, N2IC/0
n2ic at dr.att.com
>From M Glenn Vinson Jr <mgvinson at crl.com> Fri Aug 18 17:07:59 1995
From: M Glenn Vinson Jr <mgvinson at crl.com> (M Glenn Vinson Jr)
Date: Fri, 18 Aug 1995 09:07:59 -0700 (PDT)
Subject: Lord Howe Island DXpedition
Message-ID: <Pine.SUN.3.91.950818084559.9732E-100000 at crl7.crl.com>
A group of 4 operators will be traveling to Lord Howe Island next month,
arriving on September 19 and departing on September 26.
We will take 3 stations and be active on RTTY, CW and SSB.
Callsigns and QSL info are as follows:
On RTTY, VK9LZ
On CW, VK9LX
On SSB, VK9NM (yes, that is not a typo: VK9NM. I guess all 2 letter
calls beginning with "L" have been used up for Lord Howe now)
QSL all to Eddie Schneider, P.O. Box 5194, Richmond, CA 94805
Operators will be W6OTC, N4TQO, KE6FV and W6/G0AZT. We have a 40-10m
beam, a vertical for 80m and 160m, and a wire, just in case. Each
station has a small amp to run 500 watts.
We will operate as M/S in the CQWW RTTY contest and will operate RTTY and
CW at all other times when the bands--including the WARC bands--are open.
We will operate SSB outside of the contest weekend.
73, Glenn, W6OTC (mgvinson at crl.com)
>From H. Ward Silver" <hwardsil at seattleu.edu Fri Aug 18 16:59:33 1995
From: H. Ward Silver" <hwardsil at seattleu.edu (H. Ward Silver)
Date: Fri, 18 Aug 1995 08:59:33 -0700 (PDT)
Subject: DSP power
Message-ID: <Pine.3.07.9508180832.D27404-c100000 at bach.seattleu.edu>
> DSP power is NOT related to the carrier frequency in the practical cases of
> band-limited signals. The same power is needed for 9 kHz sampling of audio
> signal or 455 kHz IF if the input signals are within 4.5 kHz passband.
> A/D converter is the only limiting factor so TS-870 11 kHz 4th IF fits
> nicely with CD digitizers with 20 bits resolution.
>
Mario has a point. By undersampling (and carefully filtering out the
undesired aliasing products) you can digitize higher frequencies than
the Nyquist criterion (2x highest sampled freq) would seem to allow. The
tradeoff comes in s/n ratio, distortion, and susceptibility to in-band
aliasing. No free lunch...although some are cheaper than others.
> DSP is well entrenched in commercial rigs from Collins, Watkins & Johnson,
> Rohde & Schwarz so there is NO need to repeat some early mistakes as it is
> all software. Or shall we have FT-101, VHS, MS-DOS etc. story again?
>
> 73 de Mario, S56A, N1YU.
>
Yeah, but these rigs aren't used in environments with the requirement for
rejection of extremely strong adjacent channel rejection, high frequency
agility, reception of signals at (or below) the noise floor, etc.
Contesters and DXers tend to quickly find the flaws in receivers because
they use them to limits not explored by the commercial and military users
who require much higher s/n ratios for reliable links. Our links last for
about 10 seconds!
We will find all sorts of noxious secondary and tertiary effects from the
use of DSP that can be safely neglected in high s/n - single-channel work.
Just like the 70's and mixer design. I suspect that sufficient attention
is being paid to such effects this time around and the learning curve will
be much steeper. But there WILL be a curve.
> P.S. How many filter taps one needs for >100 dB rejection of decent
> analog filter? Is the time delay acceptable in real life?
Good question! Next question? A quick look in my references don't give a
clue about this one. Analog blow-by may actually be a limiting factor.
100dB of isolation is tough to obtain without special techniques.
73, Ward N0AX
>From force12e at lightlink.com (Natan) Fri Aug 18 18:06:34 1995
From: force12e at lightlink.com (Natan) (Natan)
Date: Fri, 18 Aug 95 13:06:34 EDT
Subject: N2PNG
Message-ID: <199508181707.NAA23622 at light.lightlink.com>
Has anyone the whereabouts of Barry, N2PNG. I need to talk to him
concerning the upcoming contest season.
thanks
Natan W6XR/2
>From sellington" <sellington at mail.ssec.wisc.edu Fri Aug 18 18:34:18 1995
From: sellington" <sellington at mail.ssec.wisc.edu (sellington)
Date: 18 Aug 1995 12:34:18 -0500
Subject: DSP power
Message-ID: <n1403373178.99644 at mail.ssec.wisc.edu>
>100dB of isolation is tough to obtain without special techniques.
Not if one cascades two filters at different IF's.
Scott K9MA
sellington at ssec.wisc.edu
>From sellington" <sellington at mail.ssec.wisc.edu Fri Aug 18 18:34:18 1995
From: sellington" <sellington at mail.ssec.wisc.edu (sellington)
Date: 18 Aug 1995 12:34:18 -0500
Subject: DSP power
Message-ID: <n1403373178.99644 at mail.ssec.wisc.edu>
>100dB of isolation is tough to obtain without special techniques.
Not if one cascades two filters at different IF's.
Scott K9MA
sellington at ssec.wisc.edu
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