SDS100 Initial Review From Phoenix

[mkt853]

Why is Phoenix such a challenging RF environment? I mean compared to places in the northeast where I would have thought the biggest problems would occur since there are so many systems saturating every public safety band.

 

[KR7CQ]

Why is Phoenix such a challenging RF environment? I mean compared to places in the northeast where I would have thought the biggest problems would occur since there are so many systems saturating every public safety band.

It's baffling. I mean, we are big metro area, maybe like the 8th largest or something now, 3.5 million people, maybe 15-20 simulcasts total, so it's a lot...but it's not as bad as other more densely populated metro areas I'm sure. Myself and others are all wondering the same thing you are wondering. Is there something special about Phoenix in terms of unusually high interference / noise floor? I don't get it either. I don't disbelieve those who have glowing reports on this scanner. I have to believe that some people are thrilled and I am happy for that, but I don't understand the night and day disparity.

 

[milcom_chaser]

And the 436 and G4 where not affected by that interference. Are the SDS100 poorly shielded, as was suggested earlier, or is it the SDR frontend receiver that are not as good as a conventional receiver and cannot handle the different kinds of nearfield interferencies that we all have now with routers, modems, computers, network and USBcabling and all those computer boxes in modern vehicles?



/Ubbe

Ubbe, you suggested it was poorly shield...


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[milcom_chaser]

Not doubting you there. I had some issues originally but firmware updates seem to have solved almost all of them fortunately.

I met with another new SDS100 owner today for lunch in a different location and all of our results, and impressions about the SDS100 being no better than and at times inferior to the 436 were the same. We both agreed that interference was a likely culprit, and that we often see insanely high noise levels. We also both agreed that neither can touch the G4 when it comes to pulling in valley simulcasts other than the one we are sitting in the middle of.

My offer of a steak dinner still stands for anyone who can meet me and show me any scanner that can even come close to picking up the various Phoenix area simulcasts the way the G4 does. They are a world apart in performance for me, and for those who I've been meeting with and talking to in the valley and even other places.

Agreeing with Paul's simple assertion regarding the G4/G5 being RX band specific.


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[milcom_chaser]

It's baffling. I mean, we are big metro area, maybe like the 8th largest or something now, 3.5 million people, maybe 15-20 simulcasts total, so it's a lot...but it's not as bad as other more densely populated metro areas I'm sure. Myself and others are all wondering the same thing you are wondering. Is there something special about Phoenix in terms of unusually high interference / noise floor? I don't get it either. I don't disbelieve those who have glowing reports on this scanner. I have to believe that some people are thrilled and I am happy for that, but I don't understand the night and day disparity.

If you drive around PHX, there are radio sites up on hill tops that are in numerous places including a huge site bordering the South area of town. It's RF dense. Wouldn't think it with the vast desert topography.


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[jonwienke]

And the 436 and G4 where not affected by that interference. Are the SDS100 poorly shielded, as was suggested earlier

By you.

And as I mentioned before, the SDS100 has more shielding than the 436, that is not held in place with the circuit board mounting screws, but soldered to the circuit board in multiple places. And the case is lined with shielding material, unlike the 436. I posted a series of teardown photos when I did the GPS mod on my unit, if you don't believe me.

 

[milcom_chaser]

Not only should holding on a site not cause fluctuating RSSI, but it should not cause the constant loss / re-capture of signal and repopulation of the various data in detailed mode.



If I use Search and stop on a P25 trunked site CC, it sits there with full signal strength displaying constantly and the NAC revealed and no blinking / loss of any of the information.



If I program a single P25 site in and set ID SEARCH On, i will see the signal "bars" icon show full signal strength for a second along with all of the relevant trunked system information, then it the signal strength shows zero and all relevant trunked information disappears for about half second -- and it repeats this forever and ever. I doubt it's unique to mine and likely what everyone experienced. But it is NOT something that anybody should experience if all you have programmed in is a single site.



If you only have a single site programmed into your whole scanner, you should see the signal strength and all relevant trunked information 100% of the time, at least until it switches to a voice channel -- at which time some information may change but you'd still see signal strength and info.



It's almost what you would expect to see if it were scanning all of the trunked frequencies on that site rather than holding on the control channel. That's not what is happening though, because I only have the control channel programmed in. But it absolutely should not be displaying/dropping data and signal every other second.



Mike

PCWIN for downtown uses Simulcast A and Simulcast B. The control channels are on different frequencies. So when scanning, the radio alternates between CC's. So there is a momentary loss of signal.


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[KB7MIB]

Verizon using the 700 MHz band for their cellular service may also play a part in the high noise floor here. I believe KR7CQ mentioned that even the G4 goes deaf close to their towers. Perhaps the cumulative effect of all of their towers is part of the problem here?

Just a thought.

John
Peoria, AZ

 

[KR7CQ]

Verizon using the 700 MHz band for their cellular service may also play a part in the high noise floor here. I believe KR7CQ mentioned that even the G4 goes deaf close to their towers. Perhaps the cumulative effect of all of their towers is part of the problem here?

Just a thought.

John
Peoria, AZ

I think you might be making a pretty strong point there. 700 MHz Verizon towers are EVERYWHERE in they valley, and they really mess with 700 MHz public safety reception for anything less than professional gear, and yes one of those towers will wipe my G4 out from 200-300 feet. There is no doubt that this has to be a factor to some degree. I believe they run about 10 MHz below most of the simulcast, but we are talking about a LOT of RF from those towers.

 

[KR7CQ]

Agreeing with Paul's simple assertion regarding the G4/G5 being RX band specific.


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The G5 isn't band specific and does just as well as the G4 with 700 MHz simulcast. But still, it's only two bands, not as many bands as a scanner has to handle, so I think he's making a fair point there.

Look, let me be really clear, I would be OK if the SDS100 couldn't pull in simulcasts from the incredible distances the G4 does. I'm willing to cut some slack because the Unications handle either one or two bands only, and because the scanner has to do so many more things and be affordable.

However, I can't even listen to my own local police department on any scanner made to this day. For me, that's unacceptable performance, and scanner manufacturers need to aim a little higher in the future.

 

[allend]

Sounds like at the end of day pulling out your hair you need to return the radio and invest in commerical gear if you want to monitor the PHX area.

Stop messing with consumer grade equipment. Look at what your time is worth at this point. From reading posts back to many of years now that the systems in PHX have always had LSM issues and RF stuff going on. The new radio seems to be working across the board pretty well on other systems except for

Arizona PHX area. Seems like you are going to have to invest a big chunk of change to get your job done right. Consumer grade equipment is not going to be the answer in your area. Its a bummer but o well. You still have alot of stuff in the clear. Its all a give and take situation.

 

[KR7CQ]

Sounds like at the end of day pulling out your hair you need to return the radio and invest in commerical gear if you want to monitor the PHX area.

Stop messing with consumer grade equipment. Look at what your time is worth at this point. From reading posts back to many of years now that the systems in PHX have always had LSM issues and RF stuff going on. The new radio seems to be working across the board pretty well on other systems except for

Arizona PHX area. Seems like you are going to have to invest a big chunk of change to get your job done right. Consumer grade equipment is not going to be the answer in your area. Its a bummer but o well. You still have alot of stuff in the clear. Its all a give and take situation.

Yup, agreed. For P25 I will be using Unication, which is professional gear, designed for public safety use. For analog stuff, my scanners and setup do a great job, but not for PS simulcast. Maybe at some point I will start playing around with Motorola radios and doing what goes into making them work on a system.

 

[Ubbe]

And as I mentioned before, the SDS100 has more shielding than the 436.....

If you're out of luck the shielding might work as a transmission line conductor and flat panel antenna resonator. It's not as easy as putting a metal box over components and ground it as much as possible.

/Ubbe

 

[pfd461]

Hello this question goes out to policefreak post #73. You were inquiring about an issue with Burlington County. I also monitor Burlington just wondering do you have the various sites in one favorites list or each site in a separate list, aka West, Northwest etc.? I was wondering what is the best way to handle that. While on that same post what is the difference between hold time and wait time in P25 systems? Thank you for any imput

 

[policefreak]

Hello this question goes out to policefreak post #73. You were inquiring about an issue with Burlington County. I also monitor Burlington just wondering do you have the various sites in one favorites list or each site in a separate list, aka West, Northwest etc.? I was wondering what is the best way to handle that. While on that same post what is the difference between hold time and wait time in P25 systems? Thank you for any imput

So I only had 1 site (Mount Laurel) programmed with all of the frequencies in that site. I had found that my BCD396T would open squelch about a second earlier than the SDS 100. So on the SDS 100 I manually increased the SYSTEM HOLD TIME - Which as I understand it determines how long the scanner stays locked on a single control channel in the system - in hopes it would catch the transmission earlier. I manually decreased the P25 WAIT TIME - a setting only found on the older Motorola Smartzone systems which as I understand it determines the time it takes the scanner to decide whether a transmission is analog or digital and properly decodes the digital. In the past drcreasing this setting below 400ms on older scanners would cause motorboating and poor digital decode on those Motorola systems. In this case both changes appeared to improve reception somewhat before i gave the scanner back to the person I programmed it for. Over in the New Jersey forum you'll find others monitoring the same system and report this is not an issue.

 

[allend]

Yup, agreed. For P25 I will be using Unication, which is professional gear, designed for public safety use. For analog stuff, my scanners and setup do a great job, but not for PS simulcast. Maybe at some point I will start playing around with Motorola radios and doing what goes into making them work on a system.

You are a smart man. The majority of the people that have been thru this frustration and stepped up the game and bought Moto Gear. The cost is higher of course but its another tool that you add to your toolbox. You have your scanner to do certain functions and surrender to its limitations and use your Moto Radio for other systems that require commerical grade equipment. Good Luck

 

[918Dave]

I'm wondering if you have a bad unit KR7CQ? I live in and primarily listen to Glendale. Also a G5 guy here. I unboxed my SDS100 a short while ago and all I can say is WOW. G5 still sounds great, but now I've got actual scanner features in a nicely packaged unit. I'm using the stock antenna indoors and Glendale is perfect copy. I'm impressed.

 

[mkt853]

You are a smart man. The majority of the people that have been thru this frustration and stepped up the game and bought Moto Gear. The cost is higher of course but its another tool that you add to your toolbox. You have your scanner to do certain functions and surrender to its limitations and use your Moto Radio for other systems that require commerical grade equipment. Good Luck

Problem is /\/\ gear is not cheap, and of course at any time encryption can be turned on rendering all of our tools useless. It’s basically why I refuse to spend on commercial gear. I’d rather have a $700 paperweight than a $5000 one.

 

[pfd461]

Thank you policefreak for the info. I think I will put each site in a separate favorites list and see how that goes.

 

[bob-k]

Hold what?

If the squelch method doesn't work or even if it does better but try setting that systems hold time to Max and see it RSSI becomes more stable.

Houk

Hold time as in delay which by default is 2 seconds or delay waiting time defaults at 400ms? Or something different and how to do so on Sentinel/Scanner itself and what might my expectations be if I do it. The Phoenix seems very knowledgeable, so I ask if another then Unidens antenna would yield better results?