sharward
Member
After much trial and error, the SacPD North Command feed is back up, but it may not be stable. Many thanks to bigRoN18 for the tips.
Sacramento P25 system
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CityNewsSupport
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Antenna Question Is The Larson Tri Band Suitable For The News Sacramento P25 System Or Is There A Particular NMO That Is Specific To The System?
Thanks In Advance
Emergency Today News
Thanks In Advance
Emergency Today News
sharward
Member
I live near the Interstate 5 and 80 interchange and just recently set up an SDR, first with a rubber duckie near the floor and later with a magnetic mount near the ceiling, both supporting 800 MHz, but neither is getting good enough reception.
Next step may be extending the antenna into the attic.
Anyone have any (other) suggestions?
Next step may be extending the antenna into the attic.
Anyone have any (other) suggestions?
ScanningHertz
Member
I got really good reception using a Yagi, pulling in a solid signal from well outside the SRRCS footprint. Terrawave T09100Y11206T Yagi Base Antenna | Scanner Master
Another option, which can work is an amplifier
Antenna Signal Amplifier/Adapter (25dB) 50Mhz-860Mhz, Powered
Compact indoor signal amplifier is perfect for indoor TV and FM antennas requiring more signal gain. The bandwidth of 50Mhz 860Mhz makes is suitable for all HDTV television broadcasts as well as standard and HD FM. The un
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LESS is more with this system.
I know this sounds counter-intuitive but you want to try to isolate the number of 1's and 0's you are receiving at slightly different times.
If you are able to get a directional antenna and point it at one transmitter that may help or you can try taking the antenna off completely, nothing says a receiver MUST have an antenna on it, if you are getting too much signal with an antenna try NO antenna. Also try orientating the antenna horizontally, this can also help.
For the simulcast system here in Cincinnati my antennas are in my basement because anything above ground causes a multi-path issue. For my portable scanners I use the stock rubber duck because a tuned antenna doesn't work well.
LESS is more.
I know this sounds counter-intuitive but you want to try to isolate the number of 1's and 0's you are receiving at slightly different times.
If you are able to get a directional antenna and point it at one transmitter that may help or you can try taking the antenna off completely, nothing says a receiver MUST have an antenna on it, if you are getting too much signal with an antenna try NO antenna. Also try orientating the antenna horizontally, this can also help.
For the simulcast system here in Cincinnati my antennas are in my basement because anything above ground causes a multi-path issue. For my portable scanners I use the stock rubber duck because a tuned antenna doesn't work well.
LESS is more.
If I had a Yagi antenna, where would I point it to for the Sacramento tower sites? I live in South Natomas.I got really good reception using a Yagi, pulling in a solid signal from well outside the SRRCS footprint. Terrawave T09100Y11206T Yagi Base Antenna | Scanner Master
Another option, which can work is an amplifier
Antenna Signal Amplifier/Adapter (25dB) 50Mhz-860Mhz, Powered
Compact indoor signal amplifier is perfect for indoor TV and FM antennas requiring more signal gain. The bandwidth of 50Mhz 860Mhz makes is suitable for all HDTV television broadcasts as well as standard and HD FM. The un
sharward
Member
Thanks for the advice.
I appreciate what you're saying. You're referring to simulcast distortion which I have read about.
And I get that there is a "sweet spot" where one has just enough signal to have a reliable connection to pick up the data. Too little results in data loss and too much results in data distortion which results in data loss as well.
So how can I determine whether my signal is too strong or too weak?
I tried with no antenna and with antenna oriented sideways and antenna oriented downward, all resulted in worse performance.
I am suspecting weak signal because the room the PC is in a studio engineered for noise isolation. Interior walls have three layers of ⅝" drywall, and exterior walls are of similar density.
My friend and I are planning getting the antenna onto the roof on a temporary basis for testing, and if successful, we will route the cable for a permanent install.
sharward
Member
I believe the nearest tower to us in Natomas is the one off Richards Blvd., visible from the freeway. I'm pretty sure that's the site of the previous dispatch center.
ScanningHertz
Member
Bercut or Richards Blvd, and yes it is the former site of Sac PD Dispatch.
Gibson Ranch also has some good flat land around it.
sharward
Member
Here's a short video that demonstrates what is happening with my signal quality.
Markinsac
Member
The nearest site in downtown is on top of the County Jail. The Bercut site isn't part of the P25 system according to all of the documentation of the licenses associated with it.
Your video is somewhat like what I see on some of my older units - on my HP II I can run a scan of active channels, but it can't receive. Your internal antenna is probably insufficient for the needs you have. If I run the signal strength, I get a bar that bounces up and down, and never get a real signal on the other two bars in that page.
Your video is somewhat like what I see on some of my older units - on my HP II I can run a scan of active channels, but it can't receive. Your internal antenna is probably insufficient for the needs you have. If I run the signal strength, I get a bar that bounces up and down, and never get a real signal on the other two bars in that page.
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If I had to take a guess based on the video I would say moving the antenna out of the room may help, it could be your drywall.
Is that a magnetic mount antenna? If so do you have it stuck to something magnetic on the shelf?
Also, have you tried moving the antenna lower in the room? Maybe someplace on the desk or behind the monitor? On my original SDR setup I stuck the magnetic base of the telescopic antennas (with the antennas fully retracted) to the top of the PC tower under my desk and it worked okay.
sharward
Member
That's my guess too, but I wonder if there a way to tell whether signal is too strong or too weak beyond experimenting.
It is magnetic but the shelf is MDF (wood product). A friend cut a 12" x 12" piece of sheet metal for me to use as a base as a cheap experiment.
Initially the rubber duckie was attached to the Airspy USB dongle on the back of the PC which is on the floor under the desk. Switching to the mag antenna and raising it up about 7 feet higher seems to have had no effect.
There’s a tower at the North Area Corporation Yard (NACY) in Natomas.
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If you have a scanner you can tell by looking at the signal meter and see if it's jumping up and down a lot. With SDRTrunk the control channel will usually switch between control and idle somewhat rapidly, kind of what yours is doing but to a degree I would expect it to go back and forth quicker than yours appears to be doing. I think you are having a mix of LSM and weak signal at the same time. This could be a challenge that may be difficult to correct no matter what you do, it may be time to start looking for a new place to live ;-) But seriously, just keep experimenting with different things until you find what works the best.
This is exactly how I do my portable SDR setup so this shouldn't be an issue.
I drove out to the city’s North Area Corporation Yard in N. Natomas, parked very close to the tower. My HP-2 (with stock antenna) could receive the Sacramento Regional System, but doesn’t receive it at home, 2.5 miles away. Checking out Yagi antennas now....
This thread is getting way off topic. Discussion about scanners/antennas should be moved to another thread; this one is for updates regarding the SRRCS P25 system deployment.
CityNewsSupport
City News Support
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Is Davis FD/PD Broadcasting On P25 Yet? Still Picking Them Up Strong On Smartnet here in West Sacramento. Was In Davis Yesterday Picked Up Nothing On P25
ScanningHertz
Member
Are you listening only to the DAVIS site?Is Davis FD/PD Broadcasting On P25 Yet? Still Picking Them Up Strong On Smartnet here in West Sacramento. Was In Davis Yesterday Picked Up Nothing On P25
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