In a related vein, have a 'presence sensor' on the circuit, AND'ed with the appropriate PL/DTMF/whatever decode.... That way, there has to be a vehicle close to the gate - ultrasonic sensor at a post, a magnetic sensor in the ground/pavement, whatever.
Would increase the security, and especially decrease the liability; I'd hate to see the gate moving unexpectedly, while someone else is going thru it or working on the mechanism, just because some hacker tried sending the tone sequence, or another employee, unwittingly. Chuk kb4mdz --- In [email protected], "Milt" <[EMAIL PROTECTED]> wrote: > > Here's an easy idea that is currently in use. A police department wanted a > way to open a garage door from the cruiser, other than calling the station > and having them push a button. Solution was to take an old radio (Maxtrac > in thsis case) laying around, install it into a metal box, bring out the > PL/DPL decode indication to drive a relay and install at the site. No > antenna on the radio, receive only. Programmed for an odd DPL on a low > usage channel owned by the PD. Cars have a channel marked "DOOR". Cop > pulls up to the door, switches to the DOOR channel and keys the mic. Door > goes up. Nice quiet and painless. Something that any competent shp can > easily accomplish. > > Milt > N3LTQ > > > ----- Original Message ----- > From: <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Saturday, May 26, 2007 4:03 PM > Subject: [Repeater-Builder] OT: Need to find a product to develop goodwill > at a tower site(s) > > > > Hello to All, > > > > I am starting to develop a future ham repeater relation with a tower > > site(s) owner and recently got a request for something unusual. The > > company has a fleet of VHF radio equipped vehicles. They want to pull up > > to a site, enter a touch-tone sequence on the mike, and open a security > > gate at the site. I could kludge together something, but would rather > > find something commercially available. Anytime I have kludged something > > together, I have ended up having to repair it for longer that I expected. > > Something with a VHF receiver, TT decode and relay contact output would be > > great. > > > > Any ides if this is even made commercially? I know that some > > fire/ambulance departments use a similar idea to open and close the > > firehouse door. Some also have the ability to control traffic control > > lights on their way to a situation. > > > > 73, Joe, k1ike > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > >
