Cook Hill Issue-436 Band Plan Bad?

[fmulder13]

Greetings All,

I was visiting Maine a couple of weeks ago. I did some MSCOMMNET scanning with a 436hp and a PSR-500. I encountered an interesting problem monitoring in my mother's house. While monitoring the Cook Hill site, the 436hp consistently missed most of the transmissions, catching only a few, while the PSR-500 caught them all. Signal strength was full on both scanners. Though I'm not 100% sure about this, I'm pretty sure the 436hp had no problem at all when connected to an external antenna in the car. I have a couple of theories.

First, there has been a long-standing source of interference near her house that used to go crazy on the MSP CSQ frequencies. It sounded like a control channel, but I never isolated the frequency. Perhaps that was fouling up the 436hp? That would be rather curious, as the PSR-500, notorious more prone to interference issues, had no problems.

Second, I'm not terribly educated about band plans, but the one for the 436hp from the master database looks strange. It is as follows:
Band Plan 0: 851.00625, Spacing 6.25.
851.00625? On a VHF system? Am I missing something here? I didn't have the chance to experiment with changing the band plan, hence my question to the forum. Could someone possibly provide insight as to whether the band plan from the database might be wrong, or, if it is correct, why an 8xx.xxxxx frequency being part of a band plan for a VHF system works?

Otherwise, anyone other insights to this problem? I'll be headed back to Maine in a little over a month, and I'll have the chance to experiment then.

Thanks to all,
Chris

 

[Voyager]

It's common for the first few bandplans on a TRS to be 800/700 MHz. Those tables are never assigned in use on a VHF-only system.

 

[Maine45]

You do not need to enter a custom band plan for either radio for a P25 trunked system.You do need to have the correct control channel; which has been 152.7425 for the MSCommNet Cook Hill site for some time. The CC will send the radio to whichever frequency the voice traffic is using.

Not sure what "master database" you are referencing.

 

[Voyager]

I think he is talking about the HPDB which comes from RR.

Even though the scanners pick up the tables from the system, the first few are for 800/700 MHz even if that band is not used.

 

[fmulder13]

Yes, I was talking about the HPDB. Interestingly enough, I was looking at the HPDB last night and saw that no band plans were made for any sites on MSCOMMNET. Perhaps I'll just have to experiment when I'm back in the state.

 

[mainetrunk]

I would take the PSR and tune in on the control channel, and once it reads the system, it will show you strength and system type. Push store. Then, just edit it for alarms, or delays.. Make sure the info goes to the scan bank you want