CalTrans Maps...

[kg6nlw]

Logical deduction for me after seeing Inigo's posted presentation, is that is the vote-scan grouping for each of those channels. As far as dispatch and end-users are concerned, they tune to Adin, Alturas, Burney, Chester etc. The dispatcher's transmissions will come across all of those Adin channels, and the end-user's radio is transparently scanning/voting those 3 channels and selecting the clearest one. If the end-user wants to reply, within a determined time-frame I'm sure the PTT will select the last-"best" channel heard to transmit back on. Depending on what that was, the transmission goes to the primary site directly, or hits one of the roadside crossband remote bases and gets back to the primary site that way.

The presentation immediately made me rethink how to scan Caltrans while mobile, and depending on my routing, I don't have to worry about the V's unless I know I'm going deep along the rural routes of 36, 299, etc. I've scanned the UHF links multiple times while deep down 36 and 299 to the coast with no luck, only got 800 transmissions so between the low power and directional antennas, the UHF links are likely not beneficial to mobile users.

Yeah, it is definitely an interesting system! In Cloverdale, I can pick up St. Helena and Diablo with two separate traffic patterns!

Regards,

-Frank C.

 

[es93546]

Logical deduction for me after seeing Inigo's posted presentation, is that is the vote-scan grouping for each of those channels. As far as dispatch and end-users are concerned, they tune to Adin, Alturas, Burney, Chester etc. The dispatcher's transmissions will come across all of those Adin channels, and the end-user's radio is transparently scanning/voting those 3 channels and selecting the clearest one. If the end-user wants to reply, within a determined time-frame I'm sure the PTT will select the last-"best" channel heard to transmit back on. Depending on what that was, the transmission goes to the primary site directly, or hits one of the roadside crossband remote bases and gets back to the primary site that way.

The presentation immediately made me rethink how to scan Caltrans while mobile, and depending on my routing, I don't have to worry about the V's unless I know I'm going deep along the rural routes of 36, 299, etc. I've scanned the UHF links multiple times while deep down 36 and 299 to the coast with no luck, only got 800 transmissions so between the low power and directional antennas, the UHF links are likely not beneficial to mobile users.

You make a good point. I thought that the roadside repeaters were those listed with "MPL." However, your logic is better than mine. Your conclusion is still conjecture though and we need a definitive answer. Once that answer is found then another notation is needed on the database page for Caltrans. I'm not sure of why the database administrators assumed everyone would understand these two abbreviations. If there isn't a Wiki page to explain this roadside repeater equipment, there should be. The database page should have a link to this page. Why people accept a database with such vagueness and imprecise information presentation is a mystery to me.