Remote Reset via RF on farm.

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How about a long string?

How about a 2km water pipe connected to a basin that drains slower than the pipe can fill it, in which is a float switch?

Or a pneumatic hose?

If it has a phone there, you can get a secure modem that will reset everything for you, modem also takes a password. We used to reset RF equipment in Seattle from Austin Texas.

What about using the squelch detect circuit of the VHF/UHF receiver at the site? I assume it's some kind of repeater. Five on/off cycles of the squelch within 2 seconds and click, relay gets toggled. Or even a DTMF command to a decoder? US Hams have been using DTMF for remote control for decades. This could be connected to the receive audio of the VHF receiver and you could use the DTMF pad on a handy talkie to key the sequence. Once the decoder saw it the output could be used to trigger your power sequence. As long as the receiver was still OK the decoder would work. You should make it your priority to discover why it's hanging though, sounds like a hardware problem, power stability problem or design issue to me.

FWIW, I have a Z80 controlled microcomputer running 4 Ham repeaters on a 5000 foot mountain 22 miles from here. It's a 2 hour trip up that mountain to push the reset button. It's been running 24/7 since 1992. I have not been up that mountain since 1999.

Hi,

I have an interesting problem, where the farmhouse is in a valey, and the only way to communicate with the outside world is to make use of a relay tower on the hill next to the house. (only about 2Km line of sight, but a

40+ minute drive by 4X4 to get to the tower)

About once a week the equipment "hangs", and needs a cold boot. That means the long tedius offroad drive to simply switch off the quipment and back on. I considered buying "watchdog" equipment, but there are so many different things, I would need about 8 watchdog's for the UHF, VHF, Radyne Satelite Modem, Linux Server, cisco router etc...

Is there not a way to modify the standard garage door remotes for longer range, so I can transmit a pulse from the house to the tower, and it would triger my "cold boot circuit" (a Pic controlled circuit cutting all power and switching it back on in sequence except the linux server which doesn't hang :-) - this I monitor via RS232 just in case )

I bought a transmitter and receiver, connected it, and it works fine, but I still have to drive to within 50 meters of the tower base to use it.

Basically just a RF pulse or code, that is read by something else that can triger one 5V pin on my pic high or low.

All I basically want is a receiver that sits doing nothing, and when receiving a signal (any type but example 5 pulses within 20 seconds) then triger the relay. (obviously a matching transmitter) FM/AM I don't really care as I will only transmit for a brief time when there is a failure. And since it is on my property (very remote) I don't see any chance of interfering with other equipment from the closest town about 160Km away.

Maybe someone has such a circuit of a tx/rx pair that will cover my range of approx 2km.

Thanks in advance.

Wilhelm wilhelm a t iseek dot co dot za

You can get this with high gain antenna, attached to normal low power thingummies. Since you are in a remote area, noise should not be a problem

try these

very easy to build, if you use 2.4GHz stuff, and the Tx and Rx are cheap or for 433MHz etc google for Yagi

martin

That is an interesting problem - and I can describe the solution I have for something that is somewhat similar. I have a DSL modem in my basement that likes to "lock up" once in a while (it's a known problem with the Westel Wirespeed DSL modems...) and what it requires is to have the power cycled. I thought about all sorts of neat things that I could do to cycle the power remotely, etc...

...in the end, my solution was a $7 lamp timer, set so that there's no power to the DSL modem from about 3-4 AM everyday, and powered at all other times. Problem solved.

Would something like this work for you? Sure is cheap - you might need to rig up some better relays (SSR or contactors) to handle all the loads you're talking about - but if all that has to be done is cycle the power, this might be a solution.

Low tech, I know...but it works!

TJL

Up to 32km with this line- use 900MHz and high gain antenna, RS-232 for simplest implementation.

There are others, run a search under: RF Modem .

Perhaps something like this might be a suitable basis for a system.

Hi,

SNIP

I'd be tempted to try using a laser pointer (fixed of course) to send a signal to the tower.

A pair of PMR radios, operating on 446 MHz. They use CTCSS tone squelch, and often have a call tune that can be used for triggering.

Can be aquired for less than $30 a pair.

Tom