Bike communications project

For the past few years John and I have used CBs to communicate on our bike trips. Being able to communicate is handy and fun. Motorcycles aren't the greatest platforms for radio communications and the CBs have limited range and voice quality. A couple years ago I bought a mobile radio on Ebay and it came with three Kenwood TK-250 VHF portables. They can be programmed in the M.U.R.S. frequency range. These radios will be an order of magnitude nicer than CB radios.

The biggest issue is interfacing the radios to the bike. For the GL1800 there are a couple different ways. Earlier this year I installed a GL2Way kit. It has a CB module and the capability to interface a second radio. This works through the CB side of the GL1800 audio system. Kennedy Technology Group makes an FRSet4 system that interfaces a radio through the intercom system. I'm going to try both systems and see which one I like the best. By default, John and Mike will use the FRSet4 system. My bike was involved in a crash so we installed the first system on John's bike.


The FRSet4 (P/N 95367...$85) is the basis of the system. It comes with a power cable.


P/N 95258 ($35) interfaces the FRSet with the GL1800 intercom system.


Harness KW14 (P/N 95265...$55) is the appropriate cable to interface the Kenwood TK-250 to the FRSet.


I bought a simple pigtail (P/N 95327...$15) to use for the PTT (push to talk) input. Kennedy also offers a weatherproof switch & mounting bracket assembly, or a box to interface the stock PTT switch with the FRSet. Both of these options are $50+. I took the cheap route.


I searched high and low for an adapter to go from the Kenwood antenna connection to SO-239 without success, so I had to use two adapters.


The innards of the FRSet. The DIP switches will be set according to the radio used.


Mike and my bike have CBs, so we'll use an adapter to route the CB and FM stereo to the same antenna, leaving the other side for the VHF radio.

Update 2012: When we installed the FRSet system on Mike's bike (a Yamaha Venture) wiring in this adapter would have been a major pain given his connectors. Instead we added a third antenna. I installed the adapter on my bike but it killed my FM radio reception so I took it off. Now I too have a third antenna.


I bought a whole package of weatherproof momentary switches for almost nothing on Ebay.


We connected the power leads to the GL1800's auxiliary power point.


The intercom harness adapter connects where the passenger intercom harness connects near the relay panel.


The radio harness is plugged in. Due to the length of the intercom harness the FRSet will have to go under the seat.


We tried several ways to try to use the factory PTT switch at the passenger connection. It's the 2-pin connector in the sheath. We had no luck. The PTT wiring isn't just two wires...it's similar to a keypad where the wires go to a computer and the computer determines a function by sensing which wires are connected.


John never plans to have a CB so we did the PTT the old fashioned way. We rewired his switch. Here John and Mike are disassembling the left controls.


The PTT switch has a set of green wires and a set of yellow wires running to it.


These wires also perform functions with other switches so we kept them connected by soldering them, but left ~1" of one of the wires connected to the PTT switch.


We connected the loose ends to the wires going to the FRSet PTT talk input.


Fishing the wires through the housing would have been nearly impossible, so we drilled a hole behind the PTT switch and ran them outside. We used heatshrink, and weatherproofed the hole. The conversion works like a charm.

We connected everything and tested it. Receive worked fine, but the transmit volume was low, so we had to apply DIP switch #1 to add 20db of gain. Now we need to get another bike converted so we can talk to one another.


Update April 2012 - We took a trip to Shoals to eat at Bomacs so we finally got to try out the radio systems. They sounded great sitting in the driveway, but at speed Mike's was pretty much unrecognizable and John's had a lot of background noise. When we headed home we changed channels from 151.xxx to 154.xxx and put the radios on low power. It worked better. I could understand what everybody was saying but there was still a lot of background (wind?) noise. We'll be trying lots of different things to optimize communications before our trip this summer.



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