Hi, I'm new here. I'm using a RTL-SDR and a 2-meter band antenna setup trying to monitor CHP Bronze (42.12 and 42.40) but failed to pick up anything. And at the same time I can pick up Pink (42.44). I drove around on I-880 but no luck on anywhere. Any suggestion will be appreciated.
Cannot pick up CHP Bronze in east bay?
- Thread starter edougawa
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mmckenna
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On VHF low band, it's ALL about the antenna.
Unless you are running an external 5/8th's wave VHF antenna (1/4 wave on low band), you aren't going to hear diddly squat unless you are right on top of them.
Unless you are running an external 5/8th's wave VHF antenna (1/4 wave on low band), you aren't going to hear diddly squat unless you are right on top of them.
What Kind of 2-meter antenna can you tell me the make and model you're using?
I purchased this antenna specifically for receiving CHP while traveling the state.
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For starters, get yourself a decent antenna TUNED to the right band. 2 meters is 136-174Mhz, CHP is "on" 6 meters, takes a whole different antenna. Also, DO NOT use a mag-mount antenna. Take the time and drill the hole for an NMO mount properly!
Regards,
-Frank C.
Regards,
-Frank C.
mmckenna
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A 2 meter 5/8th's wave antenna will act as a base loaded 1/4 wave on low band. Many hams do that, and it works. The Larsen NMO-150 would be an option.
But, as celbaseman pointed out, you'll do much better getting an actual low band antenna, doing a proper installation. Your antenna is the most important part of the radio system, so don't skimp on it. It will directly impact performance.
Get a Larsen NMO-40C and you'll hear a lot more from the CHP:
Thanks for the comments. I checked again about the antenna, it is a 6-meter band antenna from Diamond (I don’t have the model number, it was purchased some time ago and the package is lost). I have so many antennas so I mixed them up from time to time (newbie after all)
Since I picked up the signal from Pink (which is on the other side of the bridge), I assume the antenna is at least working in some degree.
Per your advices I ordered the low band antenna for 39-46 mhz (Laird WPC39S0B-001-ND) and will see how it works out.
Thanks again.
Edited: found the model number on the base. It’s diamond M685S.
Since I picked up the signal from Pink (which is on the other side of the bridge), I assume the antenna is at least working in some degree.
Per your advices I ordered the low band antenna for 39-46 mhz (Laird WPC39S0B-001-ND) and will see how it works out.
Thanks again.
Edited: found the model number on the base. It’s diamond M685S.
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mmckenna
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Make sure you have a good ground plane under it.
Should work, even though it's a bit short for CHP. An antenna tuned for 42MHz should work better.
What is a good way to check if the ground plane is good?
mmckenna
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Direct connection to the outer shield of the coaxial cable.
At least 1/4 wave length in each direction under the antenna base (not reasonable on mobile installs).
Could please you explain it in more detail? I have never done it before.
I'm using a very simple sdr app, the button only shows squelch but I'm not sure which one it is.
mmckenna
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Most antennas need a ground plane under them to work correctly. The ground plane is a conductive horizontal plane under a vertical antenna. In a mobile application, the roof of the car would be the ground plane, with the antenna mounted in the center.
That ground plane would be connected through the antenna mount and thus to the outer shield of the coaxial cable. Checking for continuity, you should see a connection between the outer shield of the coaxial cable to the vehicle roof.
If this isn't a vehicle install, then you'll need to provide a ground plane under the antenna for it to work properly. For home use, you can buy NMO base station adapters. Essentially it's an NMO mount that the antenna screws onto and will have 3 or 4 ground radials (metal rods) radiating out horizontally under the antenna to mimic the vehicle roof.
You can try the antenna without a ground plane for receiving only, but it's not going to work as well as if you have one. Ideally you do want the antenna outside your home, mounted up as high as you can safely get it, and in the clear.
The ground plane, to be ideal, would be a 1/4 wavelength long radiating out from under the antenna. With the NMO base station adapter, those would be rods about 6 feet long radiating out from the antenna base. On a car, that would be the vehicle roof. But since that would require 6 feet out from each side of the antenna, that would require a car 12 feet wide to be perfect. That's no possible for road legal vehicles, so you do the best you can.
Hey there,
I just purchased a Uniden BCD536HP and cannot pick up CHP Golden Gate Division. I used to be able to pick it up on my BCD436HP as well, with no luck. Could I be in a dead zone or are they starting to make the switch as well?
I just purchased a Uniden BCD536HP and cannot pick up CHP Golden Gate Division. I used to be able to pick it up on my BCD436HP as well, with no luck. Could I be in a dead zone or are they starting to make the switch as well?
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California Highway Patrol - Oakland Live Audio Feed sounds alive to me
mmckenna
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Switch to what?
you are using RTL-SDR DONGLE ? https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2
if you are I would recommend trying a Scanner like Uniden or Whistler to test sensitivity to make sure the SDR Dongle is working correctly Portable Police Scanner Radios | ScannerMaster.com
also, do you have Amateur Radio License? one of my HT's is Yaesu VX-8R it covers from 500kHz to 999.990MHz, I have CHP Low Band Programmed
are you just looking to monitor CHP Low Band? not any of their 700 MHz P25?
do you plan on monitoring other agencies? or just dedicated CHP?
if it's just CHP Low Band I agree with mmckenna Larsen NMO-40C would be the best
Aren't all Law Enforcement agencies in CA going digital/encrypted? I am listening to the CHP Golden Gate "ruby" and I am not getting anything. I might just be in a dead zone. I'm near HWY 85 and 87.
Weird. I am listening to the Golden Gate Wide "ruby" with no luck.
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