CA HP 70Mhz Remote Links

[Dispatrick]

What can be heard on the CA HP remote links in the 70Mhz range? Are they worth scanning? Thanks!

 

[LZJSR]

I have listened and heard the 70Mhz traffic while driving in the Pacheco Pass along SR-152 between Los Banos and Gilroy. It was a simulcast of the low band radio traffic, and seemed to be relatively low power, but I could hear the dispatch traffic. It seems like it is a fill in to cover an area which is radio silent on the normal 42'ish Mhz channels.

 

[mmckenna]

It's just a point to point link between remote sites and (eventually) back to dispatch.
You'll just hear the traffic the channel it serves hears.

They usually use directional antennas and not a whole lot of power.

I can pick up a few from work. Often you'll hear the tone remote tones, which might get a little annoying after a while.

 

[petnrdx]

Like mmckenna says they are just point to point links. They date from LONG before microwave was affordable for such things.
Many of the CHP "mid-band" links I have seen are non-unified Motorola MICOR's.
That is a radio from about the early 1970's or so.
The links were used to connect the dispatch points to mountain top base stations on VHF-LOW that communicate with the mobiles.
Newer links are also GE MASTR-II, but those date from nearly the same time.
CHP still uses them because they still work and the cost to replace them in those REALLY remote places is not yet worth the expense.
They were never intended to be received by "users".
But if you can hear the mid-band link, you hear everything the dispatcher hears and what they transmit.
The mid-band link was pretty common years ago.
Probably some other public safety agencies using them.

 

[sacscan]

I can pick up two of them for the Valley Gold here in Sacramento (72.460 MHz CTCSS 146.2 and 75.960 MHz CTCSS 173.8). I often hear traffic on them that I can't hear on the regular 42 MHz frequencies, probably because I can't have an outdoor antenna where I live. I use a telescoping 6 meter ham HT antenna on a right-angle BNC adapter on the back of my BC780.

 

[gmclam]

They are worth scanning if you are not (able to) receiving traffic from their normal VHF low band frequencies.

 

[Paysonscanner]

They are used when microwave is not available for a site. I'm not sure of all the reasons microwave is not installed at sites. Late Hubby told me it was due to not having commercial power at some sites. There were a few of these in the Sierra Nevada and at one point the 70 meg license for one was cancelled, but not because commercial power had arrived at the site. My husband worked with this stuff as part of his county civil engineering duties, but he didn't pass much of that on to me. I might have gotten bored so he was probably trying to save me from that! There was a ham repeater on that site and access to the state/county solar collection system and propane generator backup was allowed. The ham repeater was county owned.

 

[d119]

My understanding (as told by a retired CHP radio technician) is that a lot of these mid-band links have been converted to Tait equipment. Tait makes 66-88MHz mid-band equipment, so that makes sense.