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 At 06:21 PM 11/17/04, you wrote: >I have a notion to put a VHF radio on a bicycle for public service work, >and am wondering if anyone on the list has any better current draw >numbers than those at http://www.arrl.org so I can pick the radio that >will require the lightest batteries. > >The problem with a radio on a bicycle is there is no way to top off the >batteries en route except with a solar panel or with an unregulated >fork-mounted dynamo normally intended to drive a 3- to 6-Watt bulb. A >solar panel big enough to be useful (especially here) would be big >enough to make a dangerous sail if the wind blew and the dynamo, in >addition to creating whine in use, would not deliver enough charge >current to keep the battery up when in use. I do have a pair of 12 AH >AGM cells on hand that could be pressed into service; with that as a >given, I want to maximize the length of time I can operate from one or >both cells or, alternately, use a smaller battery or pair of batteries >for the same run time. > >I suppose I could use a HT for this purpose, but they do have certain >limitations I would like to avoid if possible. The biggest limitation >is the antenna mount; the second biggest is the low gain of the stock >rubber duckie and its replacements. > >Since strictly speaking this is off topic, please E-mail me any >responses at "[EMAIL PROTECTED]" or my callsign at the same ISP. > >de kg7yy > > > > > > >Yahoo! Groups Links > > > > 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/
