July 95' QEX

Thu Aug 17 13:30:39 EDT 1995

Thanks to KB1GW, WA2DHF and AA6MC for advising me to call ARRL.
They even said they would make it a sample copy and not charge
me!!  Whatta deal!

Thanks again,

73  KC5DVT   Wayne     email...ehayes at vnet.ibm.com
Austin, Texas

>From n4zr at ix.netcom.com (Pete Smith)  Thu Aug 17 18:48:20 1995
From: n4zr at ix.netcom.com (Pete Smith) (Pete Smith)
Date: Thu, 17 Aug 1995 10:48:20 -0700
Subject: Grounding
Message-ID: <199508171748.KAA08733 at ix5.ix.netcom.com>

K8DO wrote:

>Hi Barry...
>I had to think about this one for a few minutes... I would certainly be
>concerned about using the ground-system/shell of the swimming pool to
>dissipate the current surge from a strike on the tower... In all probability
>there would not be enough current through the shell to either be a shock
>hazard to swimmers, or to cause steam pocket explosions in the damp
>concrete... B U T ... It is too important to chance.... I would not tie the
>grounding system into the pool....
>
Maybe I'm being overcautious, but being in a swimming pool, or a lake, or
the ocean (particularly) when there's lightning anywhere around doesn't
"strike" me as a good idea...

73, Pete Smith N4ZR
n4zr at ix.netcom.com  *** note new e-mail address ***

Radio Free West Virginia (under construction)

>From sellington" <sellington at mail.ssec.wisc.edu  Thu Aug 17 18:53:57 1995
From: sellington" <sellington at mail.ssec.wisc.edu (sellington)
Date: 17 Aug 1995 12:53:57 -0500
Subject: DSP at IF
Message-ID: <n1403458400.72299 at mail.ssec.wisc.edu>

We won't be dispensing with analog IF filters for a while yet.  Consider 
that a pair of good crystal filters provides something over 100 dB of
rejection at less than twice the 6 dB bandwidth.  To provide that
kind of dynamic range with a DSP alone, something like 20 bits of A/D
converter
resolution would be required.  That isn't going to happen soon.

That's not to say that IF DSP in addition to good analog filters can't do
great things for receivers.

Scott   K9MA
sellington at ssec.wisc.edu

>From aa4lr at radio.org (Bill Coleman AA4LR)  Thu Aug 17 20:04:42 1995
From: aa4lr at radio.org (Bill Coleman AA4LR) (Bill Coleman AA4LR)
Date: Thu, 17 Aug 1995 15:04:42 -0400
Subject: new rigs
Message-ID: <v01520d00ac5940ec9b76@[205.160.29.40]>

>I find it hard to believe that Yaesu would
>put on a show of describing "Collins Mechanical Filters"
>if they indeed had DSP in the IF. It is my understanding
>that IF DSP replaces mechanical or crystal filters in
>a DSP radio.

Not necessarily, there are still good reasons to use analog filtering even
if you have an IF DSP.

>The Icom and Yaesu implementations are
>not true DSP radios in that sense. They still require
>standard filters...the DSP is indeed nothing
>fancier than a Timewave or W9GR unit in the AF stage.

Not necessarily.

The problem with putting a DSP in the IF of a receiver has to do with
sampling rates. An affordable DSP has a limited processing power, so the IF
frequency must be reasonably low (10-100 KHz). Higher frequencies reduce
imaging problems, but require faster digitizers and more DSP processing
power. Lower frequencies need less expensive digitization and DSP
processing power, but limit the useful receiver bandwidth of the DSP and
also result in imaging problems from nearby frequencies.

So, you may have a compromise. The advantage of having a DSP in the IF
region is it gets to do its work before the audio AGC detector -- something
an external DSP can't easily do. There's also the possibility of doing
certain types of variable bandwidth and adaptive filtering (eg heterodyne
and noise elimination).

But it takes a lot of DSP power to produce a sharp band rejection filter --
something that existing crystal and mechanical filters do well at higher IF
frequencies. It then makes sense to have analog filters in the early
high-frequency IF stages, with DSP embedded in the low frequency final
stages.

Having the combination isn't a necessarily a bad thing. In my opinion, the
proof is in the pudding. Withhold judgement until you get to try each in
similar conditions.

Bill Coleman, AA4LR      Mail: aa4lr at radio.org
Quote: "The same light shines on vineyards that makes deserts." -- Steve
Hackett

>From jerry wald <jerry.wald at sheridanc.on.ca>  Thu Aug 17 20:57:07 1995
From: jerry wald <jerry.wald at sheridanc.on.ca> (jerry wald)
Date: Thu, 17 Aug 1995 15:57:07 -0400 (EDT)
Subject: MultiTasking
Message-ID: <Pine.OSF.3.91.950817155314.19482B-100000 at hubble.sheridanc.on.ca>

Hi Guys...

I have resisted Windows but notice that most new software seems to use it.. 
Whattaya do??????

Jerry, VE3ESN, Mississauga, ON, Canada | jerry.wald at sheridanc.on.ca
---------------------------------------------------------------------------

On Thu, 17 Aug 1995 K8DO at aol.com wrote:

> Hi steve...
> I have not used OS2 at all... The gurus at the local computer shop speak
> highly of it... I plan to install OS2 in the near future and see for myself..
> (I'm currently maxxed out with building a house, shack, contest station, and
> working 12 to 14 hours a day... A new OS will have to wait until I clear the
> decks here...)  They also like the NX version of Deskview...  Windows is a
> dog!  If the public understood how badly they have been ripped off by
> Microsoft, there would be a lynching...It is the exclusive licensing
> contracts by MS that force the vendors to include MS DOS/Windows with every
> computer sold that has created the ubiquity of MS products, not their
> value...
> In any event, I  know from experience that you would like DeskView as a
> multitasking OS for DOS based software....
> 
> Cheers ... Denny
> 

>From aa4lr at radio.org (Bill Coleman AA4LR)  Thu Aug 17 22:03:22 1995
From: aa4lr at radio.org (Bill Coleman AA4LR) (Bill Coleman AA4LR)
Date: Thu, 17 Aug 1995 17:03:22 -0400
Subject: MultiTasking
Message-ID: <v01520d02ac595ee8a6de@[205.160.29.40]>

>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

>From Robert <w5robert at blkbox.COM>  Thu Aug 17 22:37:01 1995
From: Robert <w5robert at blkbox.COM> (Robert)
Date: Thu, 17 Aug 1995 16:37:01 -0500 (CDT)
Subject: new rigs
Message-ID: <9508171637.ab10092 at blkbox.COM>

I don't see how all these neat features mean much IF I still
have to pull the cover on/off to switch the amp relay in.
Has that been fixed in the new model??

-- 
73 Robert  WB5CRG  w5robert at blkbox.com   

>From Steve Runyon WQ5G  512-838-7008 <steve at austin.ibm.com>  Fri Aug 18 00:02:46 1995
From: Steve Runyon WQ5G  512-838-7008 <steve at austin.ibm.com> (Steve Runyon WQ5G 512-838-7008)
Date: Thu, 17 Aug 95 17:02:46 -0600
Subject: Multitasking
Message-ID: <9508172202.AA23683 at runyon.austin.ibm.com>

<>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....)

Yes, Macs and also PowerPCs are out there...

My original question to Denny was prompted by the notes on the 
clock running fast - I had asked if he had any experience with OS/2
and how it compared to DeskView or Windows. I'm not a software or 
operating sys guru, but it seems to beat Windows pretty handily 
for real-time multi-tasking apps. 

I'm curious as to whether anyone has experience running contest/logging
software concurrently with other programs (packet, satellite tracking,
etc.) under OS/2, and whether it also suffers from the limitations 
of Windows... 

>From John-Warren at easy.com (John Warren, NT5C)  Thu Aug 17 23:11:04 1995
From: John-Warren at easy.com (John Warren, NT5C) (John Warren, NT5C)
Date: Thu, 17 Aug 1995 17:11:04 -0500
Subject: MultiTasking
Message-ID: <1403443092-33190518 at BANJO.EASY.COM>

...on which you'll install Word, Excel and PowerPoint. Hey, wait a minute...

                                                          John, NT5C.

   (Why not give up, and just invest in Chairman Gates?)

>From Tim Coad" <Tim_Coad at smtp.svl.trw.com  Thu Aug 17 23:21:42 1995
From: Tim Coad" <Tim_Coad at smtp.svl.trw.com (Tim Coad)
Date: 17 Aug 1995 15:21:42 -0700
Subject: MultiTasking
Message-ID: <n1403449419.25705 at smtp.svl.trw.com>

        Reply to:   RE>>MultiTasking

>>You avoid Microsoft-domination by doing what I did years ago. You buy a
>>Mac....

Yeah buy a mac. Then you wont be able to compain about 95% of the software out
there running slow or quirky, CONTEST S/W included, (had to get the "C" word
into this thread") .....Because you wont be able to run it at all. But at
least it probably wont crash as much as windows.......

By the way Im writting this on a Mac and at least half the S/W loaded on this
machine was written by Microsoft....So I guess buying a Mac doesnt really help
the world domination problem either:-)

Tim - NU6S

>From darrel at dii.com (Darrel Van Buer)  Fri Aug 18 00:17:54 1995
From: darrel at dii.com (Darrel Van Buer) (Darrel Van Buer)
Date: Thu, 17 Aug 95 16:17:54 PDT
Subject: MultiTasking on OS/2
Message-ID: <9508172317.AA25710 at dii.com>

I routinely run DXBase and occasionally NA for contests under OS/2 in an OS/2 
DOS window with serial port connections to TNC and radio (in addition to serial
ports for mouse and modem).
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.

In the past, I ran this setup on a 486DX2-66 with 16MB and reasonable cache
and the interaction between programs was substantially less.  Using the lesser 
machine lets me dedicate it to the radio position in a heavily computer-using
family.

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.  Microchannel and PCI do not have this problem, but hardly anybody
uses the former, and there are very few serial boards for PCI.  For Com3 and 4
I resorted to Xacto surgery and stick-on edge connectors to get interrupt
10 and 12 [which are on the AT bus extension connector] because very few
serial boards provide built-in support.

The biggest challenge to switching to OS/2 can be device support.  Depending
on which video card, CDROM, network card, SCSI card, etc you have, it can
range from painless because the support is there, to a lot of digging for
working drivers to impossible because neither the maker norr IBM have OS/2
drivers. 

	Darrel, KI6VY
	darrel at dii.com

>From Patrick Collins <pcollins at freenet.columbus.oh.us>  Fri Aug 18 02:52:37 1995
From: Patrick Collins <pcollins at freenet.columbus.oh.us> (Patrick Collins)
Date: Thu, 17 Aug 1995 21:52:37 -0400 (EDT)
Subject: MultiTasking
Message-ID: <Pine.3.07.9508172107.A25235-9100000 at acme>

I run OS/2 now.  It works great, but if I am using NA I try not to run too
many programs.  Used Desqview in the past and found it to work very well
for DOS programs, but it needed > 8Mb of memory to run more then 2 or 3 at
once.  Who will be the first to write a multi-threading contest logger for
OS/2 Warp Connect?
______________________________________________________________________________
Pat Collins                                    pcollins at freenet.columbus.oh.us
NZ4K	