rananthony04
Member
Thanks Bob for the info, I am really considering the roof mount.
Question RE: CHP
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BirkenVogt
Member
RolnCode3 said:
What I was saying is that is going to cost 3 times what it costs for a single band radio, minus a tiny bit for the control head, etc. that will be in common. The reason ham stuff is so cheap is because it's made cheap!
Birken
For A Good, Cheap, Home Antenna...
Since I have cable TV, I put my old television antenna to use as my home scanner antenna. I works fine. It covers 54 MHz to 890 MHz (television band). It is like having several tuned antennas in one, just exactly what it is desined to do.
CHP is a little lower, but I pull in CHP fine when hooked up to it.
It saved me a lot of money, too. All I had to do was buy some cable, a balun (transformer), the proper connection for my scanner, and I was good to go. The best thing is that it was already installed and up on a mast.
Here is a mobile antenna in or near the CHP bands:
http://cgi.ebay.com/VHF-34-40-Mhz-L...oryZ4672QQssPageNameZWD1VQQrdZ1QQcmdZViewItem
Since I have cable TV, I put my old television antenna to use as my home scanner antenna. I works fine. It covers 54 MHz to 890 MHz (television band). It is like having several tuned antennas in one, just exactly what it is desined to do.
CHP is a little lower, but I pull in CHP fine when hooked up to it.
It saved me a lot of money, too. All I had to do was buy some cable, a balun (transformer), the proper connection for my scanner, and I was good to go. The best thing is that it was already installed and up on a mast.
Here is a mobile antenna in or near the CHP bands:
http://cgi.ebay.com/VHF-34-40-Mhz-L...oryZ4672QQssPageNameZWD1VQQrdZ1QQcmdZViewItem
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BirkenVogt
Member
Using a TV antenna is a good idea for the reasons you state. However it is highly directional and so it needs to be pointed at the signal you are receiving. Also it will perform better if mounted on its side so the elements go up and down rather than horizontal since all the stuff we listen to is vertically polarized.
Birken
Birken
rananthony04
Member
thx dave.
-robert
-robert
What you wrote is correct. However, a highly directional horizontal mounted TV antenna on the roof of the house (aobut 8 feet high above the roof on a pole) beats a ducky on the scanner in the house.BirkenVogt said:
I guess I could go up there and figure out how to mount it vertically. But no, I am too lazy...why bother, it works alright for me. Probably because I live in the northern suburbs of Los Angeles ("The Valley") where RF propagation is saturated anyway.
hotdjdave said:What you wrote is correct. However, a highly directional horizontal mounted TV antenna on the roof of the house (aobut 8 feet high above the roof on a pole) beats a ducky on the scanner in the house.
I guess I could go up there and figure out how to mount it vertically. But no, I am too lazy...why bother, it works alright for me. Probably because I live in the northern suburbs of Los Angeles ("The Valley") where RF propagation is saturated anyway.
In LA it's a good thing to lose that 3db of gain by keeping it horizontal vs vertical.
Acts like an attenuator.
I have a UHF Radio Shack TV antenna model mounted vertically for a T-band system here up north.
I just drilled the mast for vertical polorization.
As for hearing San Jose CHP from Sacramento, that's not much of a problem since they keep the San Jose system on repeat mode and it's broadcasting both sides
of the conversation from a 2,000ft transmitter on Mt. Allison.
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RolnCode3
Member
I never meant I was picking up the mobiles on the mobile frequency, so the fact that they're repeating the mobile freq over the base isn't really important. The distance is still about 100 miles. I can hear most of the other Bay Area freqs, but San Jose is the furthest of all of them.trooperdude said:
SkipSanders
Silent Key
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One thing to note is that using a handheld INside a vehicle will NOT work for low band comms such as CHP uses. The signal does not penetrate into a vehicle at all well. Any external antenna will help immensely, even if it's not low band itself.
CHP is migrating (slowly) to repeater mode instead of duplex base/mobile, and it's much easier to monitor an area when it's on a repeater.
CHP also uses other systems at times, sometimes as an experiment. Currently, El Cajon (East County) CHP in San Diego is mostly on the County 800 MHz RCS trunk system, though they also link in and use the normal low band channel in many areas further east. They have assigned trunk groups for all San Diego ops, but are only using the Eastern ones, so far.
This is probably the 'best' solution for CHP, to keep their own low band, but add an 800 Trunk capable radio to all vehicles programmed for use with local agencies, either on trunk or on the conventional intersystem channels. (And/or the new 700 MHz band)
CHP would have to install FAR too many sites to use 800 as their primary system, when they have to cover the WHOLE state, with all its mountains, valleys, and general 'hard on 800' terrain. 800 Works well in cities, and flat areas. When you get into complex mountain terrain, it develops huge numbers of dead spots, unless you put sites EVERYwhere.
CHP is migrating (slowly) to repeater mode instead of duplex base/mobile, and it's much easier to monitor an area when it's on a repeater.
CHP also uses other systems at times, sometimes as an experiment. Currently, El Cajon (East County) CHP in San Diego is mostly on the County 800 MHz RCS trunk system, though they also link in and use the normal low band channel in many areas further east. They have assigned trunk groups for all San Diego ops, but are only using the Eastern ones, so far.
This is probably the 'best' solution for CHP, to keep their own low band, but add an 800 Trunk capable radio to all vehicles programmed for use with local agencies, either on trunk or on the conventional intersystem channels. (And/or the new 700 MHz band)
CHP would have to install FAR too many sites to use 800 as their primary system, when they have to cover the WHOLE state, with all its mountains, valleys, and general 'hard on 800' terrain. 800 Works well in cities, and flat areas. When you get into complex mountain terrain, it develops huge numbers of dead spots, unless you put sites EVERYwhere.
That's right, Skip. When the state was surveyed for radio coverage on 800 vs VHF low, they would have had to install hundreds of repeaters and mobile relays to get reliable 800 coverage statewide. They produced a repeater-site map for this scenario, which you can see right here.SkipSanders said:
The most recent version of the ever-changing "plan" for CHP (when/if the money and 700 MHz ever become available) is for them to use a hybrid linked system of VHF-High and 700/800. VHF in the mountainous and forested areas, and a combined VHF and 800 (& 700) Mhz configuration in the flatland and urban areas. They're wanting VHF high for much improved interoperability, since hardly anybody is on low of course, I suppose with the trade-off being the loss of low-band's generally great propagation in the great rural outdoors.
Lots of reports for the CHP and other state agencies in a proposed radio unified system are at the PSRSPC (Public Safety Radio Strategic Planning Committee) website if their absurdly long URL holds together. Otherwise go here - http://rimsinland.oes.ca.gov/CTD/Public/psrspcweb.nsf/home?OpenForm - and click on "Work Products." Plenty of leisurely reading.
Thanks for the map Harry. When I looked at it I noted that the existing sites shown in the eastern Sierra (Mono & Inyo Counties) don't all have a CHP remote base in them. It does appear that they all have microwave or 70 MHz linking. The existing sites appear to be previously constructed state sites but there are many of them that are not needed to give the CHP low band coverage. I was a bit confused with the map as there are both black and red triangles as well as white and green circles. This is not explained in the legend.
When considering the need for additional sites, especially in numbers of hundreds, keep in mind that not all of the sites can be developed, just because the CHP needs them. There may be a large portion of this "hundreds" that will not be available once, and if, this plan got to the stage where the feasibility of building each site is evaluated. The reason for this non-availability would vary greatly depending on the specific locations. Since many electronic sites are located on National Forest lands I'm very familiar with many of the issues that govern electronic site location on those lands. There's a long list of resource issues, too numerous to list here, which could make a site selected by the CHP one that the Forest Service won't approve. The same situation applies to BLM land. A large percentage of electronic sites are located on the lands these agencies manage.
If the state considers going in this direction at some point in the future, I would hope they would take a hard look at this before assuming that they could build on every single site shown as a white circle on the map. They may find that the whole proposal would leave far too many areas of non-coverage due to the unavailability of sites. This issue would present itself more in the rural areas, especially in mountainous terrain and areas of public land, than it would in urban and flat areas.
When considering the need for additional sites, especially in numbers of hundreds, keep in mind that not all of the sites can be developed, just because the CHP needs them. There may be a large portion of this "hundreds" that will not be available once, and if, this plan got to the stage where the feasibility of building each site is evaluated. The reason for this non-availability would vary greatly depending on the specific locations. Since many electronic sites are located on National Forest lands I'm very familiar with many of the issues that govern electronic site location on those lands. There's a long list of resource issues, too numerous to list here, which could make a site selected by the CHP one that the Forest Service won't approve. The same situation applies to BLM land. A large percentage of electronic sites are located on the lands these agencies manage.
If the state considers going in this direction at some point in the future, I would hope they would take a hard look at this before assuming that they could build on every single site shown as a white circle on the map. They may find that the whole proposal would leave far too many areas of non-coverage due to the unavailability of sites. This issue would present itself more in the rural areas, especially in mountainous terrain and areas of public land, than it would in urban and flat areas.
OK, I finally found the document from which that map came, at http://psrspc.ca.gov/lib/1999_CBA.pdf and it's apparently still being used as a source document, although I guess funding (or lack thereof) has made all their date projections obsolete if not totally moot (by maybe a decade?). I don't see any reference to the different colors for those circles and triangles, perhaps they're just an artifact of the document being handled, reformatted, etc.Exsmokey said:
They come up with a total of 1,025 radio "sites" needed by the CHP, and since their coverage needs are the most of any agency, that's the number they seem to be going with if/when all nine other agencies eventually got into the system.
They do address your issue of site acquisition in several places, and aside from funding, that is given as the most critical item in the whole plan after frequency spectrum acquisition. For instance, at page IV-7 ("Key Steps")...
"Site Acquisition and Facilities Development – The acquisition and development
of required sites is a critical path item. This includes acquisition of new sites,
modification of existing sites, initiation of leases, vault design and build out, and
tower design and construction. This is a lengthy process, one complicated by
California’s geographical size, changing terrain, weather conditions, varying
population densities, numerous environmental agencies, radio signal propagation
characteristics and local and county regulatory entities."
of required sites is a critical path item. This includes acquisition of new sites,
modification of existing sites, initiation of leases, vault design and build out, and
tower design and construction. This is a lengthy process, one complicated by
California’s geographical size, changing terrain, weather conditions, varying
population densities, numerous environmental agencies, radio signal propagation
characteristics and local and county regulatory entities."
and on page IV-10 (Risk Management - Real Estate)
"Real Estate – Two major risks associated with real estate are:
Risk mitigation plan – The most effective means the State has to combat real
estate risks is to identify as many alternate sites as possible. Once the sites have
been identified, effort will be spent on assessing the political environment,
educating the public on project objectives, and researching the site acquisition
processes used by other entities (e.g. cellular telephone companies, personal
communications services (PCS) providers, etc.). Other efforts regarding
mitigation of real estate risk, as they relate to the environment, are to ensure strict adherence to local, State, and federal environmental statutes. The State will
designate an Assistant Project Manager to work issues associated with real estate risk."
1. Inability to acquire the necessary sites for vaults and towers.
2. Incurring significant project delays due to the inability to acquire the
necessary sites in a timely manner. “Road blocks” could occur because of
politics, current land holdings, or other environmental concerns.
2. Incurring significant project delays due to the inability to acquire the
necessary sites in a timely manner. “Road blocks” could occur because of
politics, current land holdings, or other environmental concerns.
Risk mitigation plan – The most effective means the State has to combat real
estate risks is to identify as many alternate sites as possible. Once the sites have
been identified, effort will be spent on assessing the political environment,
educating the public on project objectives, and researching the site acquisition
processes used by other entities (e.g. cellular telephone companies, personal
communications services (PCS) providers, etc.). Other efforts regarding
mitigation of real estate risk, as they relate to the environment, are to ensure strict adherence to local, State, and federal environmental statutes. The State will
designate an Assistant Project Manager to work issues associated with real estate risk."
Matter of fact, the potential problems with site acquisition, and the severity of the impact on the project comes up a lot in pages IV-7 thru IV-13, and is charted pretty well in the exhibits on IV-15 (see what I mean about the dates??) and especially on page IV-16 ("Probability: High," and "Potential Impact: High" in several factors).
This multi-agency project appears to be attached to the budget documents every year, with various changes of scope, detail, and emphasis, so apparently it's still on their drawing-boards. I believe I heard or read somewhere that the 10-agency "big picture" has been put further into the background and the focus will first be to get CHP's big piece of it off the ground first. I doubt anyone is holding their breath on it, but PSRSPC and CASEIC are still alive and kicking.
MCIAD
Member
Just a thought, and this actually worked well for me . . .
I used to have a scanner connected through the car stereo antenna. There is made a "Y" connector that will split the antenna feed to both your scanner and the car radio. It actually provided pretty good wide-band coverage. I was able to receive everything from CHP at 42MHz through Los Angeles F.D. at 800MHz.
I forget where I got mine (I think GALL's), but it was not expensive.
I used to have a scanner connected through the car stereo antenna. There is made a "Y" connector that will split the antenna feed to both your scanner and the car radio. It actually provided pretty good wide-band coverage. I was able to receive everything from CHP at 42MHz through Los Angeles F.D. at 800MHz.
I forget where I got mine (I think GALL's), but it was not expensive.
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