|This page is an attempt to correlate the interfacing schemes for various Radio models, and Sound Card configurations. Since 26th December 1998, when the sound card version of PSK31 was first introduced to the Ham community, and after much dialog, experimentation and confusion, an interfacing pattern slowly emerged. I feel that an understanding of this pattern is valuable and can save you a lot of time and grief. Please note that each circuit references various letters which will correlate with the Radio pin-outs on the various popup tables available. Just click the manufactures button below, pick your radio and read off the hook-up points.|
You have a Kenwood Radio and your hookup information is not here! Don't panic! Goto the Kenwood. Amateur Radio site, then to the "Jump To" pull down menu and... hey presto! If it is not on this list, it was never made.
If you can't find it here try this great TNC to Radio page; Hook-Up Magic
Ok! Ok! so you prefer to buy (that's a dirty three letter word) a ready made Computer to Radio Interface. Check out this nice package by N1ZZ and K1UHF. They call it the RIGblaster
Wait!!! are you hooking up a fully computer controlled Radio? One with a virtual consol? The Kachina, Pegasus or whatever? Hey! first read Georges Notes
STOP!!! If you are a FT1000MP owner, look no further. Doug McCann, VA3CR has a web page dedicated solely to that fine machine. This great site is a one stop information authority and missing it will be your loss. You are warned :) Check out http://www.va3cr.net/.
|Thomas Giella, KN4LF, has also a great web site showing hookup information for the FT1000MP Mk5. Check it put at ~ http://www.kn4lf.com/kn4lf10.htm|
|Ok, Almost there, but before we get into it, please read this email I received off Jack, K8PET if you are thinking of interfacing to a LapTop computer.|
First off, keep it as
simple as you can. This circuit shows a single connection
between the Radio Audio Output and The Sound card LINE IN, and a simple
100:1 attenuated connection between the Radio Aux. Mic IN and the Sound
Card LINE OUT.
|Oh! before we start a little word on the component abbreviation used on these diagrams. Since the decimal point was not showing up too well in cases like 4.7k ohm I adopted the European system which uses the 'k' as the decimal point. So the 4.7k ohm now will be marked as 4k7 ohm.|
|The 100:1 divider is very important because the output from the Sound Card can be in the order of 1volt into the microphone input which is nominally 10mvolt. It follows therefore that without the attenuator, microphone input overload can result, causing the normal narrow bandwidth to increase dramatically producing unwanted splatter.|
Try this hook-up
first. If you are operating clean and you are having no ground
loop problems, that's it. Read no further. Your done! There are a lot of
Hams who operate very well using just this circuit.
Note: The transformers T1 and T2 are no longer available at
I recommend contacting Bux Comm at Warehouse
211; Luenburg Drive; Evington, VA 24550; FAX
434 525 7818 or email
Buck at firstname.lastname@example.org and
tell him I sent ya! ... yea! he'll charge you double.
:) Take a
look at Buck's web page for these items at
|Now, a very simple transistor circuit can be
added to automatically switch the PTT circuit on the Rig.
This uses the RTS line in the active Comm. Port. The
voltage swing on this is -12v/-5v through +12v/+5v so this line is
always 'hot'. To isolate the RTS line from other
devices being used on the same Comm. Port, you might need to incorporate
Important: Please check that the PTT line, and/or the Keying line on your rig has a positive voltage on it and it requires a pull-down to ground to activate. These circuits will not work otherwise.
What does that mean? Well, you don't need to use a separate Comm. Port just for this application. I have a Kantronics KAM (all mode TNC) connected to Comm. Port 1 and use the same Port for my sound card modes. The KAM is switched off during sound card mode operation.
I take off the RTS, DTR and GND lines from the Comm. Port at the RS232 connector going into the back of the KAM. Since the KAM will drag the DTR line down, leave it disconnected at the KAM connector. The KAM does not use it anyway!
Ok! Included on this web site is a really nice keyboard CW program. I like the idea of being able to simply click an Icon and start operating one of a growing number of Sound Card modes now available. So CwType uses the Comm. Port DTR line to send Morse Code.
|So! you have realized that with the inclusion of the TTL circuits shown above that you now don't have 100% Radio to Computer isolation.|
Even worse maybe you still have a ground
loop problem. Well simply substitute one or both of these schematics for
there equivalent TTL version. They are the same as the two TTL circuits
above except that they use an Opto Isolator to switch the circuit.
|An e-mail off Ken, W7LAR gives us
a great tip by the way. If you want to get the Optoisolator from
Radio Shack it will probably not be a store
stocked item. You can get it direct mailed to
your home by asking the shop clerk to order it for you from there
warehouse. It is number 11305190 and costs about $3.00
Bill Strong also added that he also had problems getting Radio Shack parts but suggested going to a company called Mouser. "They advocate a call for non listed values and odd parts, 800-346-6873 Ordering can be done via Email or Phone. The On Line catalog list all. www.mouser.com" Thanks for the info Bill.
|Now, for you guys who have
negative keying on those older rigs. This problem is not as
straightforward as it first appeared. An email off Bob,
W2SR pretty well sums it up.--
Using a classic rig like those made by Drake, Collins and Heathkit present a problem. Just how do you key a transmitter that has -30 to -90 volts on the keying line? Not with your average 2N2222 or 4N33! So I looked into it and I will not try and reproduce the schematics here but will point ya! in the right direction. The first, known as the Jackson Harbor Approach, uses a high voltage transistor, MJE350. Unfortunately this kit is no longer available however if you go to http://jacksonharbor.home.att.net/keyall.htm you will find that Chuck Olsen, WB9KZY has designed a replacement called, The Keyall. He tells me it can key grid block (negative), cathode (high positive) and regular 13.8V solid state rigs - it can even key the Tuna Tin 2 transmitter - it's a solid state relay circuit. Thanks Chuck for this excellent kit.
Also checkout Radio Adventures who have a Grid-Block Adapter that is good to -200v see http://www.radioadv.com/ham_radio_equipment/accessories/bk170.htm. Art Boyars, K3KU has a great circuit for keying both +ve and -ve keying voltages. This appears in the April 1993 QST magazine, and originally in the (PVRC) Potomac Valley Radio Club Bulletin, Feb 1990. Other sources include- J.Garrett, The WB4VVF Accu-Keyer in QST Aug 1973. and D.Foster, Negative High Voltage Keying Circuit, Technical Correspondence, QST Jun 1991.
must thank Walt Hoskins, W0EDS, for his
recent enquiry asking how to interface the old Drake
wanted to run TruTTY software for CW
sound card. We
produced the circuit at the right. The diode is a 1N34 and the
Dip relay is
a 5/6 volt SPST, NO type from Mouser. #655-JWD-107-5
|Well I hope this little reference helps ya! I was getting quite a bit of email on this :)|
periodically get e-mail telling me that certain parts are no longer
available from Radio
Shack. I suggest therefore that you go to the Bux CommCo
Catalog where you get one stop
shopping for all your component needs including the hard to get
connectors. Oh! by the way Buck sells the sound card,
Little Rascal. Hey! for about $25 you get all the
components you need. You can't buy them yourself for that price! Check
ISO-KIT info here. After reading Bucks' page, go
to his Kwik-Select guide
|The N9ART Interface
designed by Jim Mitrenga
|Well! you are now really biting at the bit
and want to jump
right in there, build a new sound card interface, download that
windows software and join the Digital Revolution.
Hold it! hang loose a minute. Are
you one of those Hams that uses a non-soundcard,
serial port type, interface, and you are really
with that DOS software? You are! well join
the crowd.... but you
have realized that there is a problem. Yep! you will get tired of
cables from one system to another.
Uhmm! well, I think we have the answer to that for ya!. Lets take a look at Jim's interface. This interface will give you the best of both worlds. You can certainly join in the soundcard Digital Revolution and guarantee clean signals but at the click of a switch you cut the the sound card out and fetch in the serial port interface that feels and acts just the way you remember.
Check out the circuit diagram below. err! look familiar? It should. This interface is from an article that appeared in the November issue of QST, entitled "A Flexible Digital-Mode Interface" and is reproduced by kind permission of the author, Jim Mitrenga, N9ART.
For a complete list of
click here. If
you would like a printout of this list, simply right
click on the popup margin and click print.
download this file and print it off. Jim has made an excellent job of
his circuit theory, schematic, construction details, alignment, and
summary is full of useful links relative to both DOS and Windows
Hey! as Jim said "Now you have no excuse for not trying Amtor, Fax, Hellscheiber, MT63, Pactor, Psk31, Rtty, SSTV, et al." For more information you can e-mail Jim at: email@example.com.
|I have operated with most of the modules
listed above and have ended up with the Isolated Circuit and both the
Opto Isolated versions for RTS and DTR control. That configuration works
great in this shack.
After my initial hook-up, and all ground loops removed, I still had problems with RF getting into the computer. I found that winding the cable to the computer speaker system through a Ferrite Core about 4 turns, removed this problem.
However, other Hams were not that lucky. I remember two other cases I was helping with where a Ferrite Core was needed in the Sound Card LINE IN lead and the other was wound in the Keyboard cable before a cure was effected. This process seems hit-and-miss at best so the best approach appears to be one of trial and error.
One very last word but not by any means the least--- IMD! It is essential that your signal is clean on the air otherwise you will probably be splattering all over the band. On all the software available you will see a waterfall indicator which shows all the PSK traces available to you to work, however yours is NOT one of them. So how can you see what your signal looks like so you can take corrective action if needed? Well the other station will help you adjust your station until you have a fb trace or would you believe, there are indeed devices available that will allow you to see your own trace. Check out PSK Meter by KF6VSG or IMD Meter by KK7UQ.
To help me collect the different Radio hook-ups please send me, WM2U or submit this Form with your Radio's hookup information for publication on this page. Any comments or help would be really appreciated.
I hope this page grows with the your help and that it is found useful when interfacing you system,