March 28, 2006 14:49
Subject: Page #4, FAQ
Off road motorcycle ham radio installation.
At 04:35 PM 11/7/2005, you wrote: Updated 3-28-2006
Thanks for the tips, Ray.
Just went through the MARC Web Site, <marc-hq.org>
I'd like to use my Yaesu VX170 (not familiar with that radio, so I went to the HRO & AES catalogs and read up on them, probably a good choice for what you want to do) for 2m bike to bike communications in
an off-road environment on a Kawasaki KLR650. I've built a radio tank
bag that includes the radio and an amplifier/interface, (why an amplifier?)
It's an amp/interface that integrates audio, intercom, radio, phone, etc.
The Starcom1 - http://starcom1.com/ an has
external jacks for plugging in the headset and push-to-talk switch.
Where did you put the PTT button, we always mount them on the left handlebar under the left handlebar grip right where your left thumb is located while riding)
That's the place!
I also have brought the SMC jack to a female pass-through BNC jack (All
50 ohm stuff) to connect an external antenna to the bag. Why do you have the SMA jack to BNC jack, you can buy a short coax that goes right from a SMA connector on the radio, a short 6 ft or less using a RG316 Teflon Coax with a PL259 connector on the other end and mount an antenna on the back of the motorcycle on the rear of the frame or some place that can be grounded to the frame. Getting the antenna grounded is paramount for really good radio TX or RX on a motorcycle.
I wanted the bag to be fully self contained, with all external connections, so I could easily move it bike to bike, and take it with me when parked, without going into the bag. By having a BNC post on the outside of the bag, it will be easy to hook up any external antenna I decide to go with. Also, if the antenna vibrates or takes a big hit, the radio should be spared any major trauma.
My question now is what to do about the antenna. I'd like to get 3+
miles in open terrain. Mounting options I've considered are just
attaching the stock rubber duck to the bag, replacing the stock duck
with up to an 18" flexible whip, or hard mounting a more serious
antenna to the rear of the bike. Durability is key, as vibration,
dust, and impact are big parts of riding off road. I'm also not sure
how to tune or compensate for the extra connectors or the run of
cable to the rear of the bike.
The rubber duck would work of course, but it just doesn't have the gain to get out very far. There are antennas available from Comet that could survive the test of desert or motocross riding. I test antennas for them and work the ham radio shows with them and do know something about antennas. I also use to race in the desert so I know about what it would take for a ham radio and an antenna to survive out there. I does sound like you have the right place for the radio, in the tank bag, rapped in some foam and tied down well. With a short external antenna mounted on the frame at the back of the bike, you should be able to get well over 3 miles on 5 watts of power and an antenna mounted on the frame, or at least grounded to the frame. If you are getting electrical noise in the headset, get a filter for that. Hope this all helps. Since you live in the LA area, you are welcome to ride/trailer the motorcycle to my home in Irvine and I will try and help you get the radio, antenna and coax mounted. It is all a learning process at this stage.
Going to try this antenna, attached to the bag, for starters,
I'm riding the LA-Barstow-to-Vegas ride Thanksgiving weekend, and wanted to be ready to go for that.
If the range feels weak, I'll try a Comet, and maybe take you up on the generous offer of help with a hard mount antenna.
We just spent 4 days, (40 hours) straightening out the wiring on an 05 GW from IL. and installing GPS, Cell phone, Valentine One Radar Detector, XM Radio and APRS (Automatic Position Reporting System). Had to pull out all the wiring that other shops had put in for some of this stuff. Shorten to the right length, label, put in spiral wrap and rerun all this wiring to buse bars that I make up. Big job for one of our MARC Members.
Ray KD6FHN, MARC Chairman of the Board.