SDS100 P25 Conventional

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OceanNora
Posts: 213
Joined: 05 Mar 2018 12:57

SDS100 P25 Conventional

Post by OceanNora »

After a few years of going back and forth I finally picked up a SDS100. So far it seems to be significantly better than my 436 at monitoring COMIRS and I've found it to be solid on UHF analog as well as DMR and NXDN. However I've noticed that it's not doing as well as the 436 in terms of picking up conventional P25 frequencies. After sitting them side by side with the same model antenna, the SDS100 would miss the beginning of transmissions and would even break up in the middle of transmissions at times. The squelch and digital waiting times are identical between scanners, so if anyone else has had this issues or has any advice I'd be grateful.

Side note, I've also noticed that the SDS100 struggles with picking up sites on the analog MSP trunked system that the 436 has no problem with, all things being equal. Even on Site 5 it struggles, with significant static and much lower signal strength than the 436. Overall I'm pretty pleased with the SDS100, but those two things are holding me back from absolutely loving it. I've checked RR forums for fixes but it's hard to glean useful information from the threads that mostly devolve into people either bashing Uniden and anyone remotely associated with them and other people with no issues claiming that the first group is making things up/exaggerating.

garys
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Re: SDS100 P25 Conventional

Post by garys »

There are a number of PDs south of Boston using P25 conventional and both my SDS100 and SDS200 pick them up very well. The MSP analog system seems very location dependent and I get it well most of the time both at home on the SDS100 and in my truck on the SDS200.

Both work really well on P25 Phase 1 or Phase 2 (CLMRN), as well as DMR and NXDN.

There have been complaints about the analog audio processing and UPMan acknowledged that the scanners were biased towards digital and especially P25 simulcast systems. I don't know if the new Uniden Representative has addressed if, but if you read through the threads where he talks about upgrades, he's stated that hardware fixes are top priority, then firmware "bugs", and finally new features.

I would classify the analog audio issue as a "bug" and hopefully they can improve it.

Which isn't to say it's bad.

I would play with the squelch a bit on the SDS100. It seems to be a bit more sensitive in where it is set. Most people have good luck with 2 or 3 on the SDS scanners. OTOH, on the 536 sitting on my desk is set to 4.

Finally, try to find the threads on "Filters" over at RR. It's a complex subject and I don't know that it was ever fixed the way UPMan intended and apparently his notes are incomplete on some issues.

I agree that sometimes the moderators let a topic drift too much. A mod will delete posts if they are too far off topic or personal, but that could be a full time job.
We're peace loving people, we're not hunting trouble, but if trouble should find us, we'll stand up and fight.

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W1KNE
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Re: SDS100 P25 Conventional

Post by W1KNE »

OceanNora wrote:
19 Mar 2021 18:47
After a few years of going back and forth I finally picked up a SDS100. So far it seems to be significantly better than my 436 at monitoring COMIRS and I've found it to be solid on UHF analog as well as DMR and NXDN. However I've noticed that it's not doing as well as the 436 in terms of picking up conventional P25 frequencies. After sitting them side by side with the same model antenna, the SDS100 would miss the beginning of transmissions and would even break up in the middle of transmissions at times. The squelch and digital waiting times are identical between scanners, so if anyone else has had this issues or has any advice I'd be grateful.

Side note, I've also noticed that the SDS100 struggles with picking up sites on the analog MSP trunked system that the 436 has no problem with, all things being equal. Even on Site 5 it struggles, with significant static and much lower signal strength than the 436. Overall I'm pretty pleased with the SDS100, but those two things are holding me back from absolutely loving it. I've checked RR forums for fixes but it's hard to glean useful information from the threads that mostly devolve into people either bashing Uniden and anyone remotely associated with them and other people with no issues claiming that the first group is making things up/exaggerating.
Definitely try the filters. They work immensely at cleaning up poor signal type issues. The SDS series is very sensitive and the threshold of reception to overload is a hair thin.
I use mine primarily for RISCON monitoring and it does great with that. My x36 on the same antenna gets no reception of RISCON.
Mike Fitzpatrick
Broadcast Engineer - RF Enthusiast - Municipal Fire Alarm Collector
Owner: Scan New England - NECRAT.US
Issues with Scan New England can be privately addressed to me.

OceanNora
Posts: 213
Joined: 05 Mar 2018 12:57

Re: SDS100 P25 Conventional

Post by OceanNora »

I appreciate it guys, I'll take a look at the RR forums on the filters and play around with it over the next few days. I'm not the most knowledgeable when it comes to the RF side of things, so there's a learning curve for me when it comes to that aspect of the hobby.

garys
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Posts: 4064
Joined: 29 Aug 2005 13:07

Re: SDS100 P25 Conventional

Post by garys »

Mike knows the RF side of things a lot more than I ever will, but my impression is that the Filtering was never completed the way that UPMan envisioned. Particularly incomplete was guidance on how to use them. As a result I generally end up playing with the settings until I get comfortable with the quality. I like the Threshold settings on the x36HP scanners more, or they were at least easier to use.

For ICE I use "Invert" while for Bearcom/Commtronics I use "Normal" which is also my default. I also use Normal for CLMRN, the Boston 700Mhz Overlay, and the other P25 trunk systems.

Of course you might find other settings work better for you.

OceanNora wrote:
20 Mar 2021 14:50
I appreciate it guys, I'll take a look at the RR forums on the filters and play around with it over the next few days. I'm not the most knowledgeable when it comes to the RF side of things, so there's a learning curve for me when it comes to that aspect of the hobby.
We're peace loving people, we're not hunting trouble, but if trouble should find us, we'll stand up and fight.

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