The midland xtal rig 13-500 is a very low draw rig as suggested here. I have used an ICOM-02 with a 10W brick on my motorcycle quite effectively. As Mike points out, the key to performance is the antenna. There are several hams here in Austin TX that operate bike mobile. KB7UQD and WB5AOH might share their thoughts with you. BOth have email and are on QRZ.COM. My first motorcycle antenna was on the luggage shelf behind the passenger seat. I first used a Newtronics/hustler 5/8 antenna. The 12in sq luggage rack was not enough ground plane with the antenna at the back edge.
I added a loop of 1/2 in CATV coax to form a ground radial or plane behind the bike and that greatly improved performance. I would place the antenna behind you with a small metal base and some horizontal wire loops to the side and rear to act as ground planes. I think nearly any wire will work. I'd make it just barely rigid enough so that the bike falling by itself won't bend it but if you fall it will bend. My loops stick out about 15 inches. I have three loops each covering about 45 degrees. The wire goes out straight about 6-8 inches and then curves around reaching 15 in from the base plate at the 22 degree point. The wire then curves back in. Again there are three loops. I get a fairly uniform pattern where as before the antenna only worked to the front. The SWR is reasonable about 1.4:1 compared with 1.2:1 on a car (after playing with the length). I now use a comet dual band antenna with a dual band rig. Hope this helps. 73 Ed K3SWJ --- In [email protected], Mike WA6ILQ <[EMAIL PROTECTED]> wrote: > Most public service work is local, and on only a couple > of channels. If you are determined to have 8-10w, and > in a mobile package... I'd ask around at the local ham > club(s) and see if someone has an old crystal based 2m > mobile on the shelf - maybe a Midland 13-500, or a > Standard 826. These radios were 12-channels, rated > at 10w and did not have the current drain of a synthesizer > or a microprocessor. But you still need a real antenna. > > An alternate package would be a HT that had a real > antenna jack - maybe a BNC, TNC or even an SMA. > Then put a mobile antenna mount behind the seat and > use a true half-wave antenna (Larsen makes them for > police motorcycles and they are available on an NMO > mount). > > If you need more power then run a 2w-to-10w booster > amp behind the HT. > > If you run 12v gell cells you can charge them from your > car with nothing more than a cigarette lighter plug and > a current limiting resistor. Back when I worked the Palos > Verdes Marathon we had a couple of guys on bikes ... > both used a HT with a half-wave antenna and a small > gell cell. If the battery got low they stopped at their cars > and swapped the low one for one that had been on charge. > > I'd start with a better antenna and a proper way to hook > it to the radio. HT manufacturers know that their radios > will be hooked to coax for a mobile and either use a > common connector like a BNC or have an adapter > cable available. Some use an earphone style jack > for a external antenna connector - the Bendix-King > HT (used by forest fire fighters) and older HT-200 > were that way. > > Once you have a decent antenna you may discover > than an HT (perhaps with an external battery) is all > you need. If not, then you can consider a booster > amp, or switching to a low-current-draw 2m mobile > radio. And as I said, ask around, you might find an > old crystal rig for almost free, and it might have the > channels you need already in it. The most you might > have to do is add a PL encoder, and for only one tone > I've used a simple twin-T one-transistor audio oscillator. > > Mike WA6ILQ > > > > > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
