Are we missing the obvious here?? Are all of the mobile radios capable of
sending 1+1 or MDC type signaling?? I would think MDC especially would be
more secure than either DTMF or PL type stuff. Even if you had to buy a
small cheap voice recorder and play it back though the microphone
Scott,
I think you hit the nail on the head! Many of the suggestions received so
far call for the purchase and installation of new radios and/or microphones.
Other suggestions call for reprogramming of every radio in the fleet. Such
solutions can hardly qualify as simple or inexpensive.
Let's
I might have a cheaper answer to it all but it depends on what radios
exist in the fleet. If they are anything like the Kenwoods, they'll
have built in dtmf 2 tone encoders/decoders. I believe some Motorola
mobiles have this as well.
Program the units to encode either dtmf or 2 tone on a
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
At 04:19 PM 05/26/07, you wrote:
One other thought...
If they don't already have dtmf mics on their radio gear then I
would not consider adding them for cost and reliability reasons.
I'd probably buy some of the low cost key-chain remote control
units and the master decoder receiver.
It's
It appears that you know what you or the company wants so a
suggestion on making it work. Pager receivers work well in this type
of application, and they can be had now for nearly free. Attach it
to a DTMF board of your choosing, and you have what you ask for.
It's obvious that the company has
Joe,
I can sell you something that will do this using DTMF. Might contact
me off line at [EMAIL PROTECTED] Don't want to spray the board
with ads.
As someone else noted a different CTCSS tone set on a different
user's radio channel could be used. Only need a CTCSS decoder,
TS64DS, but
Joe,
Doing it on the repeater or base freq would allow other users to open
the gate if one did not have the code. I like the garage door
approach, but having longer range has it advantages and of course
disadvantages.
I should ask, do the users now have DTMF mikes. These are not cheap,
but
Hi Joe,
If they swapped there radios for the Kenwood radios using Fleet Sync that
would enable what your trying to do or just get a DTMF decoder and a radio
at the garage door location and that would do as well.
Mike
-Original Message-
From: Repeater-Builder@yahoogroups.com
When the comparison is figured out, don't forget the security issue. Do
you REALLY want a scheme where anyone will have access to open your
doors?
Joe M.
Ron Wright, Skywarn Coodinator wrote:
Joe,
Doing it on the repeater or base freq would allow other users to open
the gate if one did
Moving along...
There is a method/circuit found at airports where pilots tx click
radio mics in rapid sequence to turn on night-time runway lights.
It's not high security at a locked electric gate but it does work
if the secret can be kept under control.
And you wouldn't have to
I like the key click idea - get an older CES phone patch with 5 key click
dialing - when the line goes off hook (on a local battery circuit with a
relay in series) let the loop current call in a relay to activate the door
opener - no security but kinda neat and it could time out after so many
A dtmf decoder on a simple receiver would fit the bill.
The Hamtronic DTMF Decoder board has latching and pulsed
output logic. It's a great dollar value and a good learning
tool/kit to assemble.
Otherwise Intuitive circuits makes a dtmf controller.
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