Updated 7/11/04
Radio Amateurs in
the present digital world now require more serial (I/O) communications ports than
ever before. Today serial COM ports are required for such things as radio
control, rotor control, keying CW, PTT and/or FSK, controlling TNC's &
RigBlasters and any number of other peripheral devices popping up in the modern
ham shack.
Many operators install
In my research of USB-to-Serial adapters, I've learned several valuable things
such as not all USB-to-Serial port adapters work the way you would expect a
standard serial port to work. Most do not support 5 bit data used for FSK
RTTY transmission and most, but not all, will do radio control, CW and
PTT. The reason for this is because most standard serial communications
ports today use the 16550 UART (or better) chip to convert parallel data to and
from the CPU to serial data to be used on a standard 9 or 25 pin COM
port. The 16550 UART supports 5 bit data used for FSK and will
communicate with radios and TNC's, key CW & PTT and do just about anything
a COM port is required to do.
On the other hand, a USB-to-Serial port adapter is most likely to be using a
Cypress EZ-USB microcontroller as the UART (Universal Asynchronous
Receiver-Transmitter). Although the EZ-USB chipset can handle 5 bit data
used for Amateur FSK RTTY transmission, many USB-to-Serial port adapter manufactures
do not program the chip to do 5-bit code.
Since it's too difficult to tell if a certain USB-to-Serial port adapter will
run 5-bit RTTY, it's best to use a standard COM port for FSK and use a
USB-to-Serial port adapter for other functions such as radio control.
Again, some laptop owners do not have this choice, so USB-to-Serial port
adapters that are known to work on FSK RTTY are required in order run FSK.
This page will be dedicated to certain brands and models of USB-to-Serial port
adapters that are presently being used by Amateurs today and the facts known
about them. If a person's name and callsign are highlighted, I have
received permission to link their E-mail address. If you have specific
questions for these users, you may contact them directly.
Some of the links shown below may seem broken. But when I tested them
initially, they did work. This is a mystery to me but you can report
broken links to aa5au@bellsouth.net.
Microham offers USB
adapters dedicated to Amateur Radio.
According to Jozef, OM7ZZ, they are presently working on an adapter that
will be capable of transmitting 5-bit Baudot for FSK transmission. For details see http://www.microham.com/USB%20interfaces.html
The Aten UC-232A
uses the
UC-232A - Ekki, DF4OR, uses a UC-232A to control a TNC "I use
the adapter mainly for connecting the PTC-2 to my notebook. If I need two
ports, I use COM1 on the (notebook) extension unit as rig control (Icom) and
the USB-to-COM as TNC control".
Tom, GM0JHF, also uses the UC-232A and states "It will not work for keying
FSK but works OK controlling the radio, TS570D. Fortunately my Sony FX601
notebook has one serial port which to key FSK.
Bill, N3JIX, also uses the UC-232A "I've used it for Rig control, linking
to my PK232, and PTT keying, it worked fine. No, it wasn't able to do FSK
for me either... But to add another quick serial port for the PK232, it was
great."
The
Belkin F5U103 is the only confirmed adapter that does 5-bit FSK so far.
I have personally tested the Belkin F5U103. I am using it to key FSK
through a transistor interface to my Kenwood TS-870 using MMTTY and the MMTTY
plug-in for WriteLog. The trick is to set up MMTTY on the MISC tab for
FSK-Com TxD and press the USB button. In the USB pop-up window, select
option C: - Limiting Speed. However, if you are using Windows XP, this
adapter may not work. Some have said
they have it working under XP, but I have never been able to get my working -
Don AA5AU
F5U103 - Dick, KD6AZN, confirms
the Belkin F5U103 does 5-bit RTTY, radio control, CW and PTT. This is a
single USB to 9-pin male serial port adapter. The manual can be downloaded from
the Belkin website. Drivers for Windows 95, 98, ME, 2000 & XP
operating systems are also available from the site. The F5U103 is
available from CompUSA and Best Buy for $59.99.
Dick has experienced RFI into the adapter when running high power but fixed it
with a clamp-around torroid. He has not experience RFI generated from the
adapter.
Jim,
WB2TPS, also uses the F5U103
but cautions that it not only generates RFI "crud into the receiver",
it is also susceptible to RFI especially if you run high power.
Even though Dick, KD6AZN, is satisfied with the F5U103 adapter for FSK, others
have not had his success. I personally worked Dick on RTTY when he was in
WhiteHEAT - John, WA9ALS, is presently using the WhiteHEAT adapter. It is a
4 port DB-9 adapter. John says "Tries FSK, but not right" and
"Does rig control fine. Expensive, about $300.
Works great to control Icom PROII, IC-706MKIIG, and runs my telephone
modem. I also know that it does rig control for the 1000MP series."
The WhiteHEAT is available from EMJ America, Inc.
The EMJ part # is 1CTIWHI.
GUC232A - The GUC232A is recommended by West
Mountain Radio for use with
their RigBlaster interface units. With similar appearance and part number
as the Aten UC-232A, it makes one wonder if they might actually be the same
adapter.
Tom, WA5OMD, uses the GUC232A to control his RigBlaster. He runs AFSK
with his Yaesu FT-1000MP Mark-V through the RigBlaster. He has not tried
FSK. Instead, he receives RTTY with the radio in the RTTY position on VFO
A to take advantage of the narrow filters and transmits AFSK on VFO B and uses
a display offset programmed by the User Function to line up the two VFOs.
USA-49W - Roger, KN6RO, uses the USA-49W 4-port serial adapter to
control his FT-920. He comments that it will not run FSK and will not
pass cloning data through to his Yaesu VX-5 HT. The unit sells for around
$150 and is available from Keyspan resellers. Keyspan also makes a single port
unit. See "Other USB-to-Serial Adapters".
70607 - Chris, AC0M, uses the
PCCABLES model 70607. He has one to control his PK-900 and another
connected to his RigBlaster. He has used one to control various radios
including a Yaesu FT-1000MP Mark V Field. Chris states "Have never
had any problem at all with RFI to or from them even when running the Alpha 99
full bore on RTTY."
QUATECH offers a full line of USB-to-serial adapters from a single port to 16
port devices.
The single port adapter is shown here.
Thanks to Lisa at
Quatech for informing me that Quatech offers a full line of serial PCMCIA cards
for laptops. For more information check http://www.quatech.com/catalog/rs232_pcmcia.php.
98270-8 - Jim, N7US, uses the
4-port 98270-8 "for Yaesu rotor control and controlling my Mark-V with WL
and DXbase, connected to my 87A for its AlphaRemote software. I haven't
tried it for FSK, as I use the only serial port on my Dell with the RigBlaster
Plus and MMTTY".
Jim purchased his 98270-8 at buy.com.
Other USB-to-Serial
Adapters
Byte Runner makes
several models using the FT8U232AM chip.
Digi International
EDGEPORT model 301-1001-11 is a 1 DB-9 port adapter. Check NexTag.
Digi International
EDGEPORT model 301-1000-02 is a 2 DB-9 port adapter. Check NexTag.
Digi International
EDGEPORT model 301-000-04 is a 4 DB-9 port adapter. Check NexTag.
Digi International
EDGEPORT model 301-1002-08 is an 8 DB-9 port adapter. Check NexTag.
Keyspan model USA-19QW is a single
USB to DB-9 male adapter. Check pricing at NexTag.
SIIG model JU-CS0012 available at shopper.com. This device used the 16550 UART!
Syncrotech model USB-SIO-K03 is a single USB to DB-9 male adapter.
Tripp Lite model U209-000-R is a single USB to DB-9 male. Check pricing at NexTag.
USBgear model C-232-MM is a single
USB to DB-9 male adapter.
USB-Shop.com model UC 310 is a single USB
to DB-9 male adapter.
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