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At both of our stations we have of course a volunteer horn alert system. In a nutshell, Valley Com and the King Co. Radio group are anxiously waiting for us to replace the VHF receiver so they can shut down the simulcast.

Ok, with all that said my question is on the VHF receiver that is used at both of our stations. I'm trying to understand how it works so we can make sure we purchase the right replacement. Which if you are wondering the replacement is basically a digital pager in a box with some type of outputs for triggering external devices.

The VHF receiver we have now looks very similar to the link below but ours does not have a selectable channel knob.
http://cgi.ebay.com/Regency-TMH-2-VHF-Monitoradio-6-channel_W0QQitemZ120318528983QQcmdZViewItem?hash=item120318528983&_trkparms=39%3A1|66%3A2|65%3A10|240%3A1318&_trksid=p3286.c0.m14

The receiver seems simple. It plugs in to a normal 110v outlet for it's power and then on the back it has what looks just like a 2 prong A/C outlet. Plugged in to that outlet is a 2 prong electrical plug with two wires that go down in to a box which triggers the rest of the events to set off the horns.

My question is on what type of signal the VHF box is putting out when it's triggered by the tones. As a test I disconnected the two wires on the far end and put a meter on it. It read about .5v A/C. Then we had Valley Com set off our tones. The event happened so fast I could not see what the meter said other than it displayed something like "Out of Range".

One of the guys suggested that we we take the two prong plug from the back of the VHF receiver and plug it in to a 110v outlet thinking that maybe it's a simple 110v trigger that starts the sequence of event. So we tired that.... No go. It blew the circuit breaker. Luckily we did not damage anything.

Anyone have any experience/knowledge with this?

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If it's set up like any other receiver...it's a "open switch/closed switch" set up, nothing to do with power. The horns themselves should have their own A/C, the only thing the receiver does is tell it to "turn on" or "turn off".

The trip happens on the "second tone" of your tone out. The first one is normally called a "common tone." Which is true with yours, as you share a common tone with Maple Valley, as well. I believe it's 347.0, but I may be off by a couple, then the second tone is what differentiates the stations, etc.

Check this out: http://www.federalwarningsystems.com/pd ... 55334C.pdf

and look at page 2-4.

However, this isn't anything like what you are going to need. It's my guess ValleyCom will require you to purchase the pager/activator from them, so it's compatible with their paging network.

Thanks for the reply.

As I mentioned, we already know what pager box we need. All Valley Com needs from us is the paging number off the box to add to our run card.

As far as the tones, actually we don't share tones with them. They have their own and we have our own. However, Maple Valley gets alerted of every call we get so that is why there are 4 sets of tones when we get a call.

At this point all we need to know is what event is happening to trigger the event. And I suspect your right as far as the Open / Close.

We're gunna try shorting out the ends of plug and see if sets off the horns. My guess is that it's going to work.

Thanks.

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Rodentkj contact me off line. I'll get you on the right path.

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I generate Board Warnings

Sean. Just sent you a PM.

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When we went digital and 100 % TRS we got rid of our VHF radio receiver and placed a black box upstairs of our station, in this black box was our cap codes to alert our station. a relay for a open or closed circuit. No more fancy receiver, we use a 800 MhZ Trunked scanner locked on to our dispatch Talk-Group and wired in to our station PA speakers. We don't here what is happening on that Talk-Group Dispatch ch. until our black box cap code receives the signal, then it opens up our speakers, turns off the gas stove, and turns on the lights. We have no Vol. siren but this is how you do it.

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Realistic Patrolman PRO-48, Uniden BC-800XLT, Radio Shack PRO-2018, Uniden BC-895XLT, Uniden BC-245XLT, RCA RP-6100,
Realistic PRO-2006, Uniden BR330T, Uniden BCT15X

So we've got this figured out now, the VHF receiver sends a short to the Siren system. SO We're going to go with the EA1-Nighthawk Alerting device, but I need an electro-mechanical relay that when 110VAV is applied it sends a short.. any ideas on that?

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Mike C. - Batt 88
KE7QHA

My Dept website with a live Feed of Valleycom
http://www.kcfpd47.com

I'm not sure how you would connect your siren to the Nighthawk EA1, this devise is a smaller unit intended for smaller applications I think. We use the Nighthawk FAS-8 which I mentioned as the black box on our wall. This has the Digital Cap Codes in it that Dispatch activates when our digital Alpha pagers go off as well. The Nighthawk FAS-8 might have the relays built in, which I think it does.

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Realistic Patrolman PRO-48, Uniden BC-800XLT, Radio Shack PRO-2018, Uniden BC-895XLT, Uniden BC-245XLT, RCA RP-6100,
Realistic PRO-2006, Uniden BR330T, Uniden BCT15X

They call them "Ice Cube" relays, as they are similar shape & size (roughly) as an ice cube.

A very common method for interfacing different control voltages.
Ice Cube relays can be purchased with coil voltages of 12/24/110V and either DC or AC.


First, are you sure that the output of the box is 110VAC?
Or is that the voltage across the input to your station control?

I buy these relays from SPlatt Electric, Greybar (hotel) or Consolodtaed Electric (are they still around?)

73,
Nick
N7QOR

Thanks! Yes the EA-1 Nighthawk device has a 110V outlet that is activated when the digital pager alert is received! I'll look for an Ice cube relay!

Thanks,

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Mike C. - Batt 88
KE7QHA

My Dept website with a live Feed of Valleycom
http://www.kcfpd47.com

Yeah I probably didn't tell the whole story.
You will need to mount the relay to something and connect everything up. Make sure you get the base for the relay. That will offer the ability to mount it securely, and provide screw terminals to connect to.

I see a lot of Omron brand out there, but there are several makes.
Usually they will be DPDT, so you should have everything you need to provide open or closed loop dry contacts.

73,
Nick
N7QOR