MidAmerican Energy MPT-1327 system

[mws72]

Just a quick question for anyone who monitors this system. Do you always see the tones 196.6 on the voice channels and 165.5 on the control channel?

 

[radioboy75]

It's been a while since I've monitored it. I'll put it back in my scan sequence when I get home tonight and I'll let you know what I discover when I hear traffic.

 

[iascanguy]

One control channel that I can hear is using 196.6, the other 6 are using 165.5 but there are several voice channels in my area also using 165.5. The pattern I am seeing is that LCN's 1 to around 460 (the highest I have confirmed) use 165.5 and LCN's starting around 486 (the lowest I have confirmed, LCN 938 the highest) use 196.6.

 

[radioboy75]

The one control channel I can hear in my area is using 165.5 Hz. Just found this thread back so I threw it in there. I will listen for voice traffic now.

 

[radioboy75]

A voice channel that just came up was also using 165.5. (452.350 MHz) Not sure what LCN that is, but anyway...

 

[mws72]

A voice channel that just came up was also using 165.5. (452.350 MHz) Not sure what LCN that is, but anyway...

What do you see as a base freq/LCN?

 

[iascanguy]

Here is what I have worked out so far.

.0125khz Step

451.0000-452.9750 LCN 1-159 165.5
454.0250-454.6000 LCN 163-209 165.5
461.3000-462.0750 LCN 237-299 165.5
463.2750-464.7500 LCN 342-460 165.5
451.0500-452.9750 LCN 484-638 196.6
461.0500-462.5250 LCN 696-814 196.6
463.2625-464.7375 LCN 820-938 196.6

452.350 165.5 LCN would be 109
Not sure about calculating base frequencies, guessing it might be lowest LCN frequency in the group minus .0125.

Donald

 

[mws72]

Ok, that tallies up with what I have. BTW I have been listening to all the sites in the Quad-Cities and it seems that only the Bettendorf site is running. I would think the downtown Davenport site would be in use for the Rock Island Distribution Center but that doesn't seem to be the case.

 

[Ubbe]

Base frequency are LCN 0. So for the 463.2625MHz band it is 463.2625 - (820*0.0125) = 453.0125MHz
For the 461.0500 it is 461.0500 - (696*0.0125) = 452.3500MHz

/Ubbe

 

[iascanguy]

Darn, don’t know I managed to forget there was formula for that. Thanks! Now if I can just get the LCN’s to fill in the gaps from the list above.

Donald

 

[radioboy75]

What do you see as a base freq/LCN?

I'm a little confused. How are you guys monitoring this? I just dump the frequencies into my regular scanner in analog mode. Oh. Wait. I'll bet you're using Trunker with an RTL-SDR or something, right? Yeah, I'm not doing that. For that matter, I'm not even sure what a base freq is, or why it's important.

 

[mws72]

The base frequency is how the system tells a radio or group to get everyone on the same frequency, the system sends out to tune your radio to (background) the correct frequency. This is why we have a trunked systems on any radio band. Even a VHF-low trunked system is possible. the base frequency is the lowest possible and may not be use in the system but gives every radio a common point to operate from. in the early days of federal UHF trunked systems you had to program this. Now days the scanner is smart enough or the system actually broadcasts the base frequency. BTW I use Unitrunker for motorola and EDACS monitoring. I can't get it to work for MPT-1327 yet. I did use another program for MPT-1327 but it needs a discriminator taps which I no longer do.

 

[Ubbe]

I did use another program for MPT-1327 but it needs a discriminator taps which I no longer do.

I use a program that works fine from the earphone jack of a BCT15 and BCD536, so probably from most scanners.

Setting up trunking with no info!

Hi all. There is very little info available for Manawatu in New Zealand about trunking radio. I have two Uniden BCT8's that work very well on all the usual frequencies for the emergency services, aircraft etc. The NZ band plan says 406.1 to 420MHz is for Fleet Link and Team Talk Trunking and by...

forums.radioreference.com

/Ubbe