[RTTY] Wow! check out this USB to Serial adapter

[Richard Ferch]

Just a caveat, Charlie: Dave AA6YQ mentioned rotor control, radio control, 
CW and TNCs, but he did NOT mention a subject of particular interest on 
this reflector, namely direct FSK keying. Before purchasing one of these 
with the intention of using one of the ports for FSK keying, it would be 
wise to get confirmation as to whether it supports 5-bit codes at 45.45 baud.

The description of that particular device (and almost all of the others) at 
the cooldrives web site does not mention low speeds or 5-bit codes. They 
almost all give a maximum data rate, but no minimum, and most don't mention 
number of bits, although one or two say 7-8 data bits only. I did find 
another less expensive one (http://www.cooldrives.com/eipousbtosea.html) 
whose description says it supports 5-bit codes and data rates from 75 to 
1.2Mbps, but that range does not include 45.45 baud as used for amateur HF 
RTTY.

Looking at a supplier's web site (www.ftdchip.com), the FTDI FT232BM and 
FT2232C chips, which are used in some consumer USB-to-serial devices, 
support only 7-8 bit codes and 300 baud speeds and up. From another 
supplier, the Prolific PL-2303X-Edition only supports 75 baud and faster 
speeds (no minimum speed mentioned for their other devices, no mention of 
number of data bits).

So based on the information I have found so far on those web sites, I would 
have reservations as to whether any of these consumer devices (as distinct 
from special-purpose designed-for-amateur radio devices like microKeyer and 
RigExpert) can be used for amateur radio FSK without the help of timing 
software like the EXTFSK dll . (EXTFSK will work with almost any adapter, 
since it does not depend on the serial port's data rate or 
parallel-to-serial conversion, but I have been given to understand that WL, 
unlike some other software, does not support EXTFSK.)

That being said, if you have a bunch of other regular serial devices in the 
shack (like the ones Dave is using), you might be able to use one of these 
for most of them, and save your computer's one or two real serial port(s) 
for FSK keying.

One other thing to watch out for - a lot of amateur radio software, 
including MMTTY, only supports 8 COM ports (although DXLab and some others 
support 16 or even 32), so if your computer already uses up a couple (one 
for a COM port and one for a WinModem, for example), then you might find 
that while you can configure one of these 8-port devices for, let's say 
COM3-COM10, some of your ham software might not be able to see all of them.

None of this is a reason for not investigating further, just a caveat not 
to be surprised if you buy one and then discover that you had expected it 
to do something it cannot deliver.

Buyer beware!

73,
Rich VE3IAY

On Sun, 9 Oct 2005 12:22:58 -0500 , KI5XP said:


>For those of yall who read the DXLab reflector, disregard.  But for those 
>looking for USB to serial adapters, AA6YQ uses this successfully with his 
>DXKeeper database for USB to serial port conversion.
>
>Certainly this will run just about everything possible in your shack and 
>the price on a google search was only like $179.00
>
>Anyone using this or seen this?
>
><http://www.cooldrives.com/usb-8com-usb-multi-port-serial-adapter-eight-port->http://www.cooldrives.com/usb-8com-usb-multi-port-serial-adapter-eight-port-
>rs-232-serial-usb-adapter.html
>
><http://www.vscom.de/produkte/vscom_usb-8com.html>http://www.vscom.de/produkte/vscom_usb-8com.html
>
>
>Charlie
>KI5XP
>



-- 
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.344 / Virus Database: 267.11.13/126 - Release Date: 09/10/2005