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ZL3AI > APRDIG 03.11.06 02:47l 184 Lines 7516 Bytes #999 (0) @ WW
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To : APRDIG@WW
Message: 15
Date: Tue, 31 Oct 2006 13:31:21 -0800
From: "Stephen H. Smith" <wa8lmf2_at_aol.com>
Subject: Re: [aprssig] desirable laptop computer features?
gregg_at_wonderly.org wrote:
>Dale Blanchard wrote:
>>Stephen H. Smith wrote:
>>
>>>etc.
>>>Unfortunately, virtually NO consumer mass-market laptops have serial
>>>ports anymore. You will have to go to higher-priced business and
>>>specialty-market machines to get real ports. (This is why I just
>>>paid USD $1500 for a new Panasonic Toughbook CF-51 15" CoreDuo
>>>laptop through a specialty reseller, instead of buying a similar
>>>consumer market machine for under $1000.)
>
>I don't really think this is as big of an issue as some make it out to
>be. It really depends on the software that you are using, which
>USB->Serial adapter you get, and then how you can configure that
>adapter based on the manufactures software support for "setting" the
>comm port. The keyspan devices, as has been mentioned here before,
>seem to be the best choice.
>
>Stephen, I think you've discussed using the keyspan devices before.
>Can you share more about your need for a real port?
I've never used the Keyspan devices but have used a variety of other
devices. From my experiences:
1) Many drivers try to configure themselves at COM5 or higher. This
presents a problem with many legacy programs that only offer the classic
COM1 through COM4 that DOS knew. For example the "Memory Control
Programs" for configuring and saving the memory channels of various Kenwood
radios. Many GPS config or monitor utilities. Or even the programming
utiltiies provided by the landmobile radio manufacturer formerly known as
GE that TO THIS DAY distributes DOS-BASED programming utilities for their
latest and greatest P25 digital radios!
If the the USB dongle's driver does let you force it onto a lower legacy
COM number, you will often find that serial-portless laptops have already
"commandeered" COM1 through COM4 for modems, serial IR links, bluetooth
virtual serial ports, cell phone and PDA programming links, etc.
Note also that while the COM selectability is usually present in Win XP
drivers, it almost never is in Win 98 drivers and may or may not be in Win
2K drivers.
2) Incompatible with non-standard baud rates and word lengths. Many
dongles won't work at 110 baud (for ASCII RTTY applications) or 45 baud
5-bit BAUDOT code for "classic" RTTY operation. A surprising number of them
will only do the standard baud rates that are powers of two starting at
300.
3) Non-constant latency in the USB-to-serial or serial-to-USB conversion.
This is not usually a problem when the handshake lines are merely
controlling the flow of bytes into/out of the serial port UART. However
many ham apps use the handshake lines in unorthodox ways. The simple
soft-modem applications for RTTY and SSTV that feed clipped and limited
receive audio into the handshake line of a serial port for pulse-count
demodulation usually won't work with the dongles. The delays for the state
change, from the serial port pin to the USB side to back to a virtual COM
port inside the PC are non-constant, screwing up the demodulation by
counting microseconds between zero crossings.
On the transmit side, some applications wiggle a single outgoing serial
port handshake line to directly key the FSK input on some HF transceivers
for sending classic RTTY, or to send CW by connecting an open collector
transistor across the radio's CW key jack. Again, the variable latency of
the program-to-USB-to-serial conversions make it difficult or impossble to
reconstruct a precisely-timed 45.45 baud RTTY FSK rate or precisely formed
CW characters.
4) Windows absolutely maddening "plug-and-pray". Many times I have had
the experience of having Windows automatically DE-INSTALL the driver for a
particular USB device if the machine was booted several times without the
device being present. Then when you DO connect the device on a subsequent
boot, Windows stupidly acts as though this is a brand-new
never-before-seen device and prompts you through the whole driver
install drill AGAIN, nagging you for the "manufacturer's CD". Yes, you can
usually tell it to look somewhere in the /WINDOWS or /WINDOWS/SYSTEM32
directories for the driver, but it's a pain in the neck, especially if you
are booting a mobile computer and just want to get underway in a hurry.
--
Stephen H. Smith wa8lmf (at) aol.com
EchoLink Node: 14400 [Think bottom of the 2M band]
Home Page: http://wa8lmf.com --OR-- http://wa8lmf.net
------------------------------
Message: 16
Date: Tue, 31 Oct 2006 14:24:55 -0800 (PST)
From: "Tyson S." <timbercutter_at_yahoo.com>
Subject: Re: [aprssig] Service monitors
IFR for $1,000.00
http://cgi.ebay.com/IFR-FM-AM-1200-Service-Monitor_W0QQitemZ330042641580QQihZ01Q
4QcategoryZ1504QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
------------------------------
Message: 17
Date: Tue, 31 Oct 2006 16:37:56 -0600
From: Ron Tonneson <ron.tonneson_at_gmail.com>
Subject: Re: [aprssig] Service monitors
Does the IFR 1200 have a spectrum analyzer? I know in the older model, the
IFR 1000, only the IFR 1000S has the spectrum analyzer. The IFR 1000 that
I have does not.
Ron - K0QVF
------------------------------
Message: 18
Date: Tue, 31 Oct 2006 18:30:50 -0600
From: Mark Earle <wa2mct_at_mearle.com>
Subject: Re: [aprssig] Service monitors
IFR 1200 has a spec-an. The 1200 either has, or not, a tracking gen.
Tracking generator makes duplexer tuning easier, but for most people is
not absolutely essential.
Ron Tonneson wrote:
>Does the IFR 1200 have a spectrum analyzer? I know in the older
>model, the IFR 1000, only the IFR 1000S has the spectrum analyzer.
>The IFR 1000 that I have does not.
--
) ) de WA2MCT Mark
( ( Echolink 99190 Grid Square EL17HQ
) ) You will be assimilated... oooh, coffee!!
_|****| http://www.findu.com/cgi-bin/find.cgi?wa2mct-7 Home
( | | http://www.findu.com/cgi-bin/find.cgi?call=wa2mct-9 Mobile
`|____| wa2mct_at_mearle.com wa2mct_at_juno.com wa2mct_at_arrl.net
------------------------------
Message: 19
Date: Tue, 31 Oct 2006 22:17:37 -0400
From: "Rod,VE1BSK" <rodpadmore_at_ns.sympatico.ca>
Subject: Re: [aprssig] desirable laptop computer features?
Thanks again to those who contributed to the discussion arising from my
questions earlier today. I hope the comments were as valuable for others
as they were for me. 73 de Rod.
------------------------------
Message: 20
Date: Wed, 1 Nov 2006 21:45:30 +1300
From: Ian ZL1VFO <zl1vfo_at_yahoo.co.uk>
Subject: [aprssig] Re: Service monitors
An HP8920A is one of the things I get to use at work.
One quite useful function, if I could get it to go, is the ability to print
out to an attached serial (RS232) printer. However, as these are somewhat
rare these days, connecting it up to a PC to capture the printed data is
the next best option.
Does anyone know of a program / utility which can be run on a PC, capture
this serial data 'printed' by the HP8920A, and convert it to a BMP / GIF /
PNG or some other image file? Preferably without having to cough up some
$$, as I'm not sure how I'd be able to justify it to the bosses (or rather
accountants) at work...
-Ian ZL1VFO
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