GPS Data for Icom IC-9700

Don’t want to build your own? I now sell these and an alternative design with a better, fixed external unit on my shop!

The Icom IC-9700 has a GPS data input available but no oficial accessory from Icom. It’s a 2.5mm TRS connection that allows users to connect a GPS unit with an RS232 output to the IC-9700 and use that data for DSTAR transmission. There are several GPS units on the market that can provide the data but they are often expensive standalone units or cheaper, older generation units with lower sensitivity and performance when it comes to tracking GPS satellites.

I wanted a cheap, compact solution with good performance and an external antenna so I built my own.

Parts list:

GPS Puck unit with RS232 output – https://www.aliexpress.com/item/32878492421.html
12v to 5v Regulator – https://www.unmannedtechshop.co.uk/product/micro-bec-voltage-regulator-3-3v-5v-12v (My GPS needed 5v.)
Screw Terminal DB9 connector – https://www.aliexpress.com/item/32879710103.html (Make sure it’s the correct fitting to match your chosen GPS connector. Mine was the Male Nut version.)
2.5mm TRS audio lead – https://www.ebay.co.uk/itm/2-5mm-GOLD-Stereo-Jack-to-2-5-mm-Jack-Audio-Cable-Lead-5m/192884532103

Construction is very simple. The regulator fit’s inside the screw terminal DB9 shell providing 5v to the GPS unit using the 13.8v supply from the radio PSU. The RS232 serial data is then passed to the IC-9700 via the 2.5mm TRS audio lead.

IC-9700 GPS connector

The finished adaptor complete with external GPS unit.

IC-9700 External GPS

As expected, it works very well and allows users to place the GPS antenna outside where it has a good view of the sky.

— UPDATE —

I’ve had a few questions about how my adaptor is connected. Below are the basic details. Remember this could be different for your GPS.

2.5mm Jack Tip – DB9 Pin 2 (TX Data on my GPS unit)
2.5mm Jack Ring – DB9 Pin 3 (RX Data on my GPS unit)
2.5mm Jack Sleeve – DB9 Pin 5 (Ground on my GPS Unit)
+5v from regulator – DB9 Pin 9 (DC 3.6V-5.5V supply on my GPS unit)
-v from regulator – DB9 Pin 5 (Ground on my GPS Unit)

6 Replies to “GPS Data for Icom IC-9700”

  1. Hi Sean.

    I’ll add a little more details to the post sometime today which should help.

  2. Thanks for all that info,I fix all this and works fine at my 9700.I want to ask if this works also at my 710E?

  3. I don’t own a 710E anymore but it should work fine with it so long as you use the correct plug and get the RX and TX the correct way around!

  4. I need to change what? I can try just the way is for 9700, I am afraid I do some damage to the radio

  5. Nikos, you just need to check the pinout for the GPS data port on the 710 and see if it is wired the same as the 9700. It’s serial level data so I don’t think it will do any damage to try. I’ve checked my D700 I have here and it looks like the tip and ring connection is reversed so if you swap them over it may work.

    EDIT

    I’ve tested this with my Kenwood TM-D700 and it works fine. Just swap the tip and ring on the plug.

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