THE JIST

This page presents information about interfacing an RS-232 port to an ICOM IC-92AD. This is a very handy capability because it allows you to use software to program the memories on this and other types of radios. Programming the radio via the key pad works and if you're accustomed to texting on cellular phones you may do okay. But having the software and interface is so much quicker, faster, and allows you to save a copy of your "valuable" frequencies too. You'll have to figure out the interface connections for your radio if it's different than an IC-92AD.
ICOM IC-92AD

I've updated this article a few times...
Update #1. Click here for information about programming software.
Update #2. Click here for information about a better way to make the pin connections.
Update #3. Click here for an important WARNING about the pinout diagrams on the Internet.

Recently I found that my ICOM 92AD's memories were a mess. It was not the fault of my radio I must say. It was just me, entering frequencies as I found them. I wanted to clean them up a bit but doing so via the radio's interface is - uhm - troublesome to say the least.

ICOM produces software for the radio and cables as well. If you are familiar with ICOM its radios and optional accessories don't come cheaply... but it's top notch equipment. Most of my gear is ICOM equipment. When I was in the military we used ICOM receivers and we never had a bit of trouble with them. Now that I am retired I'm sticking with the equipment - though pricy I have never had one quit on me yet.

Not wanting to buy a cable I did a bit of research and made an acceptable interface cable from stuff in my "parts-is-parts" box.

I think you will find this quite simple to do as well. It took me about 30 minutes AFTER I figured out the pin-out of the IC-92AD. I found some information at Wikipedia but it didn't specify the location of the pins on the radio so I did some digging around in my HM-175GPS (microphone for the 92AD) to get a start. Since I've done some of the work for you this should be a breeze if you have soldering experience and a steady hand. Here's what you will need to put this together:

  1. IC-92AD
  2. Male DB-9 Connector
  3. 9 ft. - 24 AWG Stranded Wire
  4. 2 in. - 20 AWG wire
  5. 3" - 1/16 in. Heat Shrink
  6. Wire Cutters
  7. Sharp Knife
  8. Bright Light
  9. Tweezers or Hemostats
  10. Solder
  11. Soldering Iron
  12. Heat gun, but a liter will do
  13. Loop or Magnifying Glass
  14. USB to Serial Interface
  15. USB driver software
  16. RS-92 software
  17. Patience

Gather the items listed above and prepare your workspace. Once done, have a sam-ich. Sam-iches are tasty.

After your tasty sam-ich, plug in the soldering iron and while it's warming up, cut three equal lengths of the 24 AWG wire. Since my project needed a USB to Serial interface I got away with 1 foot lengths of wire. If you have a serial connector on your PC you should make these wires about 3' long.

Prepare each end by stripping off about 3/16" of the insulation.

Solder one end of each wire to the DB-9 connector's Pin 2, 3, and 5. See below:

DB-9 Detail - Figure 1.
Figure 1. Back of Male Connector

Now prepare the loose ends of the three wires as follows:

Cut three equal lengths of the heat shrink and set them aside.

Cut three 3/4" lengths of insulation from the 20 AWG wire.

Slide one piece of the 20 AWG insulation on one end of one wire and carefully slide on one piece of heat-shrink tubing. Align the cut end of the wire, 20 AWG insulation and heat-shrink so they are all just at the loose end of the wire as shown immediately below. Once done, heat the heat-shrink to fix the pieces in place. Figure 2 shows them misaligned, but it details the pieces should be pretty good.

Wire detail - Figure 2.
Figure 2.

Repeat for the remaining two wires.

As goofy as these are, these will be the connections on the radio side of your cable. Cheesy yes... cheap certainly... functional: 100%.

Update #2: I have discovered an alternative way to make these little connector wires that is much better and will last longer. Go to Radio Shack or similar store and buy a cheap set of DP-9 male pins - the type they expect you to crimp and connect yourself. Attach these to the wires and solder. Crimp the shoulder of the pin on the insulation of the wire. Now the cool part. Using a Dremel tool or file, file down the tip of the pin. They're hollow and fit perfectly on the little pins in the IC-92AD's 12 pin connector. Add small pieces of heat shrink and you're good to go.

If your computer is pretty new you may not have a DB-9 serial port on the box. If so, you will need to use a USB to Serial Interface cable. If you have a DB-9 serial connector on the computer (9 pin plug) skip the following couple steps.

Install your USB to Serial Interface software if you haven't already. I found that a cable from Prolific worked for me. You can get similar cables from www.newegg.com. I used Prolific's PL2303 model. As a side note this cable interfaced perfectly to my RadioShack Pro-97's PC/IF Serial Cable. I had to go to Prolific's web site and download the Vista version of their compatible driver. For Vista I had to install the driver before attaching the cable to the computer. On XP I attached the cable first, then installed the driver - go figure. This was the same (driver first, then connect device) when installing software drivers for ICOM's PCR-1500 wideband receiver... another cool product from ICOM.

Plug the USB cable into the computer.

Update #1: Install the RS-92 software. BTW: RT Systems provides another Windows-based program for many radios to include the ICOM IC-92AD. You can find this site at RT Systems.

Update #3: WARNING: I have found that the pinout diagram in the IC-92AD Service Manual appears to show the pins in reverse order to how they are when looking down into the connector. BE CAREFUL and check for grounds to get your radio's pin orientation. There are two grounds in there (pins 6 and 8) and one +5VDC (pin 2). Test, retest, then connect!

Now for the tricky part... you have to use the tweezers to connect the loose ends of your interface cable to the 92AD. Follow the drawing below EXACTLY. This connector has +5VDC and Grounds. You can toast your interface or radio if you make a mistake here.

Check Figure 3 to see the end result. Note... this isn't rugged and you will not want to move the radio around once it's connected.

Connection detail - Figure 3.
Figure 3.

With the radio facing you:

  • Pin 5 of the DB-9 connector (Ground) goes to Pin 8 in the 92AD connector. Pin 8 is at the 11 o'clock position looking down into the connector. Pin 8 is to the left of the flat part in the connector. This is shown here as the top left wire.
  • Pin 3 of the DB-9 connector (TxD) goes to Pin 4 in the 92AD connector. Pin 4 is at the 5 o'clock position looking down into the connector. Pin 4 is on the bottom right side of the two pins closest to the front of the radio. The Orange/Yellow wire is Pin 4 in the picture above.
  • Pin 2 of the DB-2 connector (RxD) goes to Pin 5 in the 92AD connector. Pin 5 is at the 7 o'clock position looking down into the connector. Pin 5 is on the bottom left side of the two pins closet to the front of the radio. The Green wire is Pin 5 in Figure 3.

Check out this cheesy drawing for a connection detail. Figure 4.

Interface Detail - Figure 4.
Figure 4.

Plug the DB-9 into a serial to USB converter cable if you don't have a DB-9 connector on the computer. If you do, plug the cable into the computer.

Go into Windows's control panel and open "System." Then open "Device Manager." Find the COM port setting. For me it was COM4, but it could/will be different for you.

Start up the RS-92 software. Adjust the COM port setting to match the COM port setting in the computer. This setting is under "Options," "COM Port." Once it matches click "Retry" on the main display.

The radio should come on. If it doesn't turn it on manually. If the "Retry" comes back check all your connections and ensure smoke isn't coming out of anything. If it still doesn't work, turn off the radio and swap the two wires from DB-9 PINS 2 and 3 around. Then "Retry."

If all goes well the RS-92 software's display should look something like Figure 5 once it connection to the ICOM IC-92AD.

Software Display - Figure 5.
Figure 5.

If you continue to have trouble give me a call on 145.49 (KE4UP) or 146.73 (W4QR) if you're local to HAMPTON, VA and if not send me an e-mail at pcitizen -at- msn.com. Put "92AD Interface" in your subject line. If you don't I won't respond because I won't see the e-mail.


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