Having Trouble Monitoring CHP

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ArtP

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I'm new at scanning and recently purchased a Uniden BC95XLT with software, that is a handheld unit with small antenna. I have no trouble using the scanner and programming. In fact, I can monitor my local sheriff/fire etc. without any trouble. Trying to monitor CHP is not working for me and I cannot figure out what is wrong. I'll try and offer as much information as possible in hopes someone can point me in the right direction.

I live in Southern Lake County. It's a mountainous region with peaks as high as 4000 ft and valley's as low as 1000. The dispatch center servicing my area is Ukiah, which is about 40 miles away as the crow flies. I almost never hear CHP radio traffic and when I do, it's dispatch that I pickup, never the mobile units. Sometimes days can go by without picking anything up.

At first I suspected I am simply too far away, but CHP units are very common along the highway here, one mile from where I live. Of course they must be able to hear dispatch and I should be able to pickup their mobile radio traffic when in my area. Again, I can easily pickup other agencies who cover the same territory. The same holds true if I travel 5 miles up or down the highway -- nothing, or very rarely.

I do travel to busier Napa and Sonoma counties too, and rarely pickup CHP in those counties. Just as my home county, I can easily pickup other police agencies.

Something else I find odd. My CHP area is known as "Clearlake Area", with a full office and all, but apparently is dispatched out of Ukiah. These are two distinctly different areas with a mountain range separating them. I just find it odd the Clearlake area office doesn't have its own dispatch. Or am I missing something?

Here's the frequencies I have programmed:

Ukiah base 42.56
Ukiah mobile 42.72

Santa Rosa base 42.80
Santa Rosa mobile 42.20

Napa base 42.42
Napa mobile 42.66
 

lbfd09

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I suspect that it is your antenna. The gain on most low band antennas is par at best. But the good news is that many agencies use this band because of it's ability to penetrate and over come the line of sight rule that the upper bands have. I would bet that using a six, ten or even an eleven meter antenna would cause improved reception for you. This how even would be at the cost of a loss in the high, uhf, and 800 areas.

Transmissions from the mobile units is limited. Both in time used and in distance. I know I have one of what I consider the better scanner antennas that was made and have limited reception of CHP. Normally no more than 7 to 10 miles. This is because I am on the ground level, yet on a mast of 35 feet. If I were to switch to my 6 meter omni, I'd most likely double the range.

Another limiting factor is that not all CHP cars are equal, some are designed for metro use, while others for the rual area. That means something like 50 vs 100 watts on the transmitter.

To answer the question why is Ukiah dispatching for Clearlake? That is because there is not enough traffic to maintain the cost of a dispatch in each and every office. You will see in the valley that as a prime example Merced dispatches for the Modesto, Sonora, Merced, Los Banos, Mariposa, nad Madera offices.
 

lbfd09

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I just now realized handheld and small antenna. Decrease the sensitivity even more, as I was using base antennas as a reference. A couple more reasons that you can hear the SO and FDs is because most of the time those transmissions are over repeaters. This allow most within that radio system to hear just about all the traffic. I suspect that your reception of those units would also be limited listening on the repeater input or on a simplex channel.
 

ArtP

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lbfd09,

Thanks for the reply!

I suppose I'll have to learn about the characteristics of different bands, or spectrum. If you or anyone else can offer an informational link regarding this, I would appreciate.

For now, could I simply imitate what CHP mobile units use for receiving and use something like a thin 4 foot antenna?

I'll also confirm that I'm sure you're right about my local sheriff mobile units using a repeater. Much of the sheriff activity occurs 20+ miles from where I live, yet I can hear the mobile units just as well as dispatch, but once in a while I'll pickup a weak signal from a mobile unit (so this doesn't entirely add up). One of the four antenna the sheriff uses is only five miles from my house. Sheriff broadcasts in the 155 range.

Another question, if I may... Within very close proximity, I can drive to a mountain top 1000' higher than my house which offers some prominence (highest peak around). If I get a significant improvement in CHP reception, or not, what does this say?

Thanks again for the help!
 

mmckenna

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It's likely your antenna.

The local sheriffs office here has scanners in the Sergeants cars. The only way they could get reliable reception on the scanners on the low band (CHP) was to install a dedicated low band whip on those cars. They now refer to the sergeants as "whips", because of the antenna.

You will likely not get much on the hand held antenna. You need a dedicated low band antenna to do much.

Ukiah vs. Lake County, it's just an economics thing. There isn't the need for a dedicated dispatch center for every area. You will likely find that your local CHP office has the capability to transmit/receive, but they usually don't have the call takers and consoles there to handle the calls directly. That sort of equipment costs a lot, and the staff to keep those centers running 24x7 costs a lot to.
 

ArtP

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I'm having trouble finding a low band antenna of any type -- at least one that states it's intended to capture the 40's frequency range. I'm not sure if such a thing exists that can be fastened directly to my scanner via BNC or if I have to mount directly to my vehicle.

Thanks again for the help!
 

mmckenna

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You won't find a suitable antenna that will attach to your hand held, at least not one that will actually work. You need to have either a base or a mobile antenna.

Portable antennas on low band are out there, but they are very poor performers. This is one of the reasons that CHP uses the extender/vehicular repeater system that utilizes VHF High band portables, specifically using 154.905MHz.

And, yes, Motorola and Kenwood make low band portables, but they don't work well enough for this application.
 

markclark

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ArtP

I'm sorry to tell you, but you're' attempting the impossible. You'll need a quality low band antenna with an NMO mount. Here's a link:


eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices


I'm not sure if the seller sells mounts. Buy a high quality NMO mount. No mounts with molded connectors or any of that CB junk. I have three of these and they perform as well as any Antenna Specialists and Laird low band antennas I've owned.
 

PaulNDaOC

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I use a multi-band magnetic mount with a bnc connector on a hand-held in my car and can hear L.A. CHP down in San Diego 100 miles away as opposed to barely picking up the same transmitter 15 miles away when i have just the rubber duckie.

Ukiah CHP uses multiple transmitter sites over a two-county area, and even with the best of antenna you probably won't hear dispatch talking to units on the coast.

A good place to find antennas as well as advise are at any Ham Radio stores that may be in the area.

Good luck. CHP can be a fun agency to listen to.
 

Mojaveflyer

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Another source on line is Cheapham.com. They have magnetic mount bases and NMO mount antennas available at very reasonable prices. I bought a Larsen 6 meter antenna and cut it down to 42.5 MHz. Works great!
 

OpSec

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Another limiting factor is that not all CHP cars are equal, some are designed for metro use, while others for the rual area. That means something like 50 vs 100 watts on the transmitter.
That is flat wrong.

All the marked cruisers (sedans, pickups etc) have 100w mobile radios which feed a lowband unity gain antenna on the roof. The motors have a lower power output and a compromised antenna, so they will be harder to hear with a marginal receive setup. The cars are built to be used anywhere in the state at any time.

OP, you need an appropriate outdoor or mobile lowband antenna to maximize your CHP reception. As for your confusion about where the dispatch centers are, each division has one or more comm centers that are responsible for several areas. Each CHP area office does not have their own dispatchers as that would be unfeasible to have several hundred comm centers in the state. The comm centers are linked to the radio towers by microwave and/or phone/fiber lines, so the comm center can really be located anywhere in it's coverage area.
 
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gman65

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Take a look at the Diamond M685NMO antenna. It is about $25 on HamCity.com

It made a big difference for me and allows me to pull in traffic from neighboring divisions as well. It will not be great for VHF/UHF but will work nicely for CHP traffic.

I've tried a triband NMO, the Comet EX-510BNMO worked ok. However, two I had broke pretty easy.

Good Luck
 

oracavon

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I use a multi-band magnetic mount with a bnc connector on a hand-held in my car and can hear L.A. CHP down in San Diego 100 miles away as opposed to barely picking up the same transmitter 15 miles away when i have just the rubber duckie.
That's exactly what I need. Can you tell me specifically which antenna you have? I've read that a lot of multi-band antennas have poor low band performance, so want to make sure I'm getting one that works well in OC on my car.

Thanks.
 

W6KRU

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That's exactly what I need. Can you tell me specifically which antenna you have? I've read that a lot of multi-band antennas have poor low band performance, so want to make sure I'm getting one that works well in OC on my car.

Thanks.
I am in the same boat. My multi-band antennas are stone deaf on vhf-low and my vhf-low antenna is stone deaf on vhf-high. Thank goodness they both work OK on 800.

The ST-2 sounds like it is worth a try at home but I don't have space for a 10' antenna.
 

ScannerDude244

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I am in the same boat. My multi-band antennas are stone deaf on vhf-low and my vhf-low antenna is stone deaf on vhf-high. Thank goodness they both work OK on 800.

The ST-2 sounds like it is worth a try at home but I don't have space for a 10' antenna.
I have a ST-2 that I was using for low band it work ok, but one of the cable adapters went bad. I got a used
maxrad low band antenna just need to get a NMO mount and I use a Moto maxtrac for chp.
 

W6KRU

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I have a ST-2 that I was using for low band it work ok, but one of the cable adapters went bad. I got a used
maxrad low band antenna just need to get a NMO mount and I use a Moto maxtrac for chp.
I have a maxrad low band(MLB3400) and it works well for vhf-low, I can hear Border, Inland, and Southern Divs. But it is stone deaf on vhf-high. I can't hear air or marine at all. My scanner doesn't even stop when on Wx scan and I can hear 3 Wx stations with a rubber duck with 2 of them showing full scale.
 

ScannerDude244

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I have a maxrad low band(MLB3400) and it works well for vhf-low, I can hear Border, Inland, and Southern Divs. But it is stone deaf on vhf-high. I can't hear air or marine at all. My scanner doesn't even stop when on Wx scan and I can hear 3 Wx stations with a rubber duck with 2 of them showing full scale.
After looking at the antenna i'm not sure if it's a maxrad I don't see any markings on that say maxrad on the crome part or less it came off after years of use. In the inside and it has 27-31 not sure if it's tune for that or it's the model number.
 

oracavon

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I am in the same boat. My multi-band antennas are stone deaf on vhf-low and my vhf-low antenna is stone deaf on vhf-high. Thank goodness they both work OK on 800.

The ST-2 sounds like it is worth a try at home but I don't have space for a 10' antenna.
I considered an ST-2 for my attic, but it wouldn't fit. So I tried a Grove omni, which just barely fit, and I was pleasantly surprised with its low band performance.
 
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