Arild Jensen wrote: > ----- Original Message ----- > From: "Norm of Bandersnatch" <[EMAIL PROTECTED]> > > >> I once bought a car remote control lock kit to try flashing a light on the >> boat from a distance but the useful range was too short. >> >> In the JC Whitney catalog I have seen devices to control things from a >> distance, to turn on your house lights from your car or turn on your car >> from inside the house which might work like this. Range would be the >> big >> problem. >> > > REPLY > Small airports have for a long time used Radio triggred field landing > lights and more recently USCG has tried the system on marine fog horns in > remote places that does not warrant continuous service. > > The idea being you trigger the PTT button to break squelch about 5 times > quickly. > These five squelch breaks are noticed by the radio reciver and then a relay > is triggered to turn on the lights or the fog horn as the case might be. > > A timer leaves the lights or fog horn running for maybe 15 minutes to half > an hour each time it is triggered. > > Technically speaking: a squelch burst would trigger a VOX circuit and > increment a counter chip. When the last count is triggered, the counter > output drives a transistor to fire the relay. This has been standard > technology for ham radio repeaters for at least 20 yeas that I know of and I > am sure I did not hear about it till after it was already in use for a > decade or so prior to that. It should not be much of a challenge for any > ham who makes their own rigs or is involved in seting up a 2 meter > repeater site. > Range would be comparable to any other VHF radio. In fact you may have to > desensitize it a bit. We used 400mW 2 meter radios for traffic light > control. This is low power and as such not restricted by requiring an FCC > licence for each station. Range was 3/4 mile according to my own field > tests. And without using any hi gain antenna. Our antenna were bare wire > dipoles hand cut on the bench from SS welding rod. > > Arild > I'd like to see the regs that permit low powered, unlicensed operation on 144-148 Mhz.The only unlicensed control operations I'm aware of have specific bands, such as RC, LPRS, CB, etc.
I was under the impression only the government (military) were authorized to transmit in that range at any power. Jim _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [EMAIL PROTECTED] To unsubscribe send an email to [EMAIL PROTECTED] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
