Drumheller

[harryshute]

I am planning a trip to Drumheller in Starland County soon. The City not the pen Last time I was there I logged 151.475 P25 for the federal correction service there. It is not in TAFL but some of B.C.'s federal prisons are for some reason. I also see 151.145 and 151.325 are listed in the old printed Alberta frequency list.

Does anyone have any other confirmed frequencies for the institution.

It is also interesting to note that fire and EMS reverse the inputs/outputs on their UHF System.

Harry

 

[Jay911]

When I last visited Drumheller, I did find the fire setup indeed backwards. I don't know if it has to do with the fact that they are dispatched from Red Deer (far as I can tell) and have a repeater about halfway between the two towns to bridge the gap via RF (instead of wireline or microwave).

 

[harryshute]

Jay I think you hit the nail on the head. I was going to ask if Drumheller was dispatched out of Calgary or Red Deer. When Edmonton dispatched the County of Parkland west of the city they reversed the inputs and outputs. I was given the technical reason back then but it escapes me. Something about using one antenna to transmit on both 412 and 417 Mhz is not good. Now that Edmonton is out of the picture they have switched back to normal inputs 5 mhz over the output.

Harry

 

[RBerezowski]

Jay I think you hit the nail on the head. I was going to ask if Drumheller was dispatched out of Calgary or Red Deer. When Edmonton dispatched the County of Parkland west of the city they reversed the inputs and outputs. I was given the technical reason back then but it escapes me. Something about using one antenna to transmit on both 412 and 417 Mhz is not good. Now that Edmonton is out of the picture they have switched back to normal inputs 5 mhz over the output.

Harry

You can't mix transmitters and receivers in the same half of the band at one radio site. The transmitters will desense or overload the receivers. The filters aren't sharp enough to filter out a local transmitter that close, and/or using the same antenna, with that narrow a frequency separation (kHz). You need the 5 MHz frequency separation.

For this example, the rule of thumb is all transmitters at a site should be in the 412.xxx MHz range, all receivers in the 417.xxx MHz range. So, in order to install an intermediate repeater, the intermediate repeater has to be reversed if it needs to receive a 412 MHz frequency from the host radio site. Therefore, the intermediate repeater needs all receivers in the 412.xxx MHz range, and all transmitters in the 417.xxx MHz range, i.e. the need for reversed pairing.

Rob