PSR 500: Mike V., et al: Question On CH-Hi, CH-Lo, Base Freq. Offsets, Table, etc.

[BOBRR]

Hello,

Have a new PSR 500.
New at this, and am trying to learn, so please bear with me.

Have seen various posts talking about base frequencies offsets tables, ch-lo and ch-hi etc. settings.

Haven't come across this when I use Don Starr's software to program the unit.

When, and under what circumstances is it necessary or required to use these kinds
of settings or inputs ? For what purposes, please ?

Would appreciate any explanation very much.

Thanks,
Bob
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"Based on the database entries, these tables should work:

Table Ch-Lo Ch-Hi Base Freq Offset Step
0 380 435 155.4150 380 15.0
1 436 453 157.2000 436 12.5
2 454 759 157.4700 454 15.0......."

 

[kikito]

When, and under what circumstances is it necessary or required to use these kinds
of settings or inputs ? For what purposes, please ?

Those type of settings are mainly used in the Motorola Type 2 (3600CC) systems in the VHF/UHF frequency range.

As of late, there's very few newer P25 systems also on the VHF/UHF range that *might* require Tables values set due to operating on the Implicit mode and they don't transmit the voice frequency (VC) assignments over the control channel (CC). But like I said, it's not of much concern to most people at this time since there's very few of those around.

The only other thing is for people that use the older generation of GRE scanners (Pro-96/2096) and monitor P25 systems in the VHF/UHF range. Due to a "bug" in those scanners, they also need to set up some "out of the ordinary" Tables to make it work.

 

[mikey60]

All Motorola and P25 systems use tables to control where the radios tune when the control channel tells them which channel a conversation is occuring on.

On 800 Mhz Standard and 800Mhz Splinter and 900Mhz Mototola systems, the radio has the correct tables internally, so no custom table is required. On most P25 systems, the table information is actually transmitted on the control channel data stream, so the radio can pick that up on it's own, and do not need to be manually programmed (P25 Auto).

Custom tables are used when it's not possible for the radio to determine what tables it should use automatically. Generally this is true for VHF and UHF Motorola systems (and some P25 Systems that don't transmit the information).

EDACS and LTR systems don't use tables at all, so there is no need for them in that instance.

Mike