SDS200E - P25 reception come and goes from one day to another

[haimgil]

Hello everyone


I own the Uniden SDS200E, the trouble is the house i live in, is located in a low geographic spot and unfortunately, i can`t install a decent antenna on the roof due to some issue with the neighbours.

Yesterday i got the new Tram 1094 antenna and i located it on the highest place inside my house, right next to the ceiling (a photo is attached).

I was glad that i started receiving very good signals from the P25 sites of the local police system (40-60dBm in comparrison to 100-119dBm that i received before using the Tram 1094) so finally i was able to hear more than one sentence in a row.

The problem is the reception changes from one day to another, i know that weather changes can affect the reception on analog frequencies, my question is -
can it affect digital frequencies as well?

I have to mention that today i still managed to get the same good signals, but the audio in some part of the day - was just terrible.

Can i improved it somehow by changing some of the values in the settings regarding the reception?


Haim

 

[natedawg1604]

Given you have an SDS, I'm assuming you're issue isn't simulcast. It sounds like maybe your near the edge of reception from the control channel.

You might try putting the antenna anywhere outside, like the front porch, on a post or somewhere outside that isn't terribly visible. Also with weak reception it may help to get a yagi antenna, although that would be harder to conceal outdoors.

Being in a low geographic spot sucks, if you can can get creative and find some way to put some type of antenna outdoors that may be the best option. Maybe build some type of small random structure that people wouldn't associate with antennas, and use the structure to hide the antenna.

If you have any trees, maybe figure out a way to hide an antenna in some tree branches.

 

[slicerwizard]

On the bad days, hunt around for a better antenna location.

 

[haimgil]

Given you have an SDS, I'm assuming you're issue isn't simulcast. It sounds like maybe your near the edge of reception from the control channel.

You might try putting the antenna anywhere outside, like the front porch, on a post or somewhere outside that isn't terribly visible. Also with weak reception it may help to get a yagi antenna, although that would be harder to conceal outdoors.

Being in a low geographic spot sucks, if you can can get creative and find some way to put some type of antenna outdoors that may be the best option. Maybe build some type of small random structure that people wouldn't associate with antennas, and use the structure to hide the antenna.

If you have any trees, maybe figure out a way to hide an antenna in some tree branches.

Thank You for your answer I appreciate it

On the bad days, hunt around for a better antenna location.

I thought so too. Thanks

 

[iMONITOR]

Interior walls have hidden metal air ducts, and cable/power bundles that can cause issues if and antenna is too close to them. Maybe move the antenna along the wall to see if you can find a sweet spot.

 

[rvacs]

@haimgil - so I used to have P25 probs with my SDS-200 when I was on a fringe area of P25 Simulcast.

#1 help was to use an antenna geared for the band 700-900 Mhz. And Yagi worked perfect !!! Major improvement in reception and was very inexpensive. The antenna you are using Tram 1094 is perfect for other bands but not really setup for 800Mhz P25.

Take a look at this Yagi (or any 800mhz Yagi - ebay is good too) - its inexpensive and pointed to the tower direction you will be very happy.

Amazon.com: weBoost Outdoor Directional Yagi Antenna with N Female Connector 301111 for 700/800/900 MHz Band

Buy weBoost Outdoor Directional Yagi Antenna with N Female Connector 301111 for 700/800/900 MHz Band: Network Antennas - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Watch my Simulcast Video Comparison - I use Yagi's in this video...see at 1:12 in the video:

 

[iMONITOR]

Interesting post/demo however I see a problem with your setup that could cause problems that could greatly skew the results.

Your yagi antennas are too close to each other. Having the yagi antennas positioned as you do (side by side), they are blocking signals from one side or the other or both.

I had a SDS200, (2)BCD536HP and a BCD996HP all connected to two vertical antennas coupled though a diplexer and distributed to a Stridsberg MCA204M active multicoupler. This is a more accurate method of providing a comparable signal to all the scanners without the influence of the other antennas in close proximity of each others. My results were great, all four scanners behaved the same. In fact my 536HP's and 996P2 worked so well, I sold my SFS200 and bought another 996P2. Granted your results will vary and I'm not saying this will be the case for everyone. I apparently am in a unique location that provides me with an RF enviorment where even simulcast works well with all P25 scanners, even Whistlers.

 

[haimgil]

Interior walls have hidden metal air ducts, and cable/power bundles that can cause issues if and antenna is too close to them. Maybe move the antenna along the wall to see if you can find a sweet spot.

You are absolutely right. In a matter of fact, there is a live cable wire who touches the antenna and actually preventing her falling, but now, when i think about it, i guess it can affect the reception. I will move it to another spot. Thanks 👍😄

 

[haimgil]

@haimgil - so I used to have P25 probs with my SDS-200 when I was on a fringe area of P25 Simulcast.

#1 help was to use an antenna geared for the band 700-900 Mhz. And Yagi worked perfect !!! Major improvement in reception and was very inexpensive. The antenna you are using Tram 1094 is perfect for other bands but not really setup for 800Mhz P25.

Take a look at this Yagi (or any 800mhz Yagi - ebay is good too) - its inexpensive and pointed to the tower direction you will be very happy.

Amazon.com: weBoost Outdoor Directional Yagi Antenna with N Female Connector 301111 for 700/800/900 MHz Band

Buy weBoost Outdoor Directional Yagi Antenna with N Female Connector 301111 for 700/800/900 MHz Band: Network Antennas - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Watch my Simulcast Video Comparison - I use Yagi's in this video...see at 1:12 in the video:

It says it is for cellular freqeuncies, will it still work without any problem with the P25 system?

 

[rvacs]

@haimgil - Is your P25 system in the 700-900Mhz. range? If so like most are then yes it will work great !!

 

[Ubbe]

I was glad that i started receiving very good signals from the P25 sites of the local police system (40-60dBm in comparrison to 100-119dBm that i received before using the Tram 1094)

That huge difference in signal level indicates that you have started to receive interferencies.

Try the different filter selections for a department or site and also IFX. Use the D-Error and Noise values as an aid by first configure them to be shown on the display. Then look for the lowest values for both of them while receiving a signal and when testing out different settings. The filter settings are trying to block out any interferencies so look for the lowest signal strength in dBm and not the strongest signal. Maybe engaging the 20dB attenuator will keep the interference low enough to not have any influence on your reception.

/Ubbe

 

[haimgil]

I will try this, thank you

 

[CanesFan95]

I had one of those "weBoost" / "Wilson" Yagis and it was borderline useless. Try a better brand like Laird or PCTEL.

 

[nessnet]

Ubbe above is on to something.....

The hint is " 40-60dBm in comparison to 100-119dBm that i received before". If you are getting -40 or in that range one of 2 things:

1. You are standing looking right at the antenna or are damn close.

2. You have RFI - (radio frequency interference).

I'd bet on #2. As Ubbe has pointed out numerous times here, the chip used in the 100 & 200 is very 'wide'. Basically, if there is a strong signal within (what was it Ubbe?), it will cause problems and experimenting with filters and IFX are very good suggestions.

 

[haimgil]

I`d say them both #1 and #2 this is the right answer. a filter would help here? because physically i don`t have place to relocate the antenna. no luck for me...

 

[nessnet]

I`d say them both #1 and #2 this is the right answer. a filter would help here? because physically i don`t have place to relocate the antenna. no luck for me...

Sometimes even moving an antenna a small distance can make a huge difference. Try a few inches or a foot or so.....

 

[haimgil]

Sometimes even moving an antenna a small distance can make a huge difference. Try a few inches or a foot or so.....

Believe me, i wish i had

 

[ArtU]

Try a much shorter 800mhz antenna instead of that Tram. That Tram is so large it likely is sending strong VHF/UHF stations in the SDS200's front end. Put the stock antenna on it, all the way down, and if still getting the issue move it to the horizontal position. Mine is currently at the shortest position, and angled at a 45 degree between Horizontal and Vertical for best reception.