My SDS200 is making concerning sounds on EDACS once in a while

[Marauder]

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^ A sample of what occasionally happens to my SDS200 while scanning EDACS. It will do that with multiple antennas, it will drop conversations sometimes when it happens, it might linger for a little bit but the scanner will go right back to normal usually. The only other times this happens is when some UHF freqs bleed into each other but this has a more distinctive sound. This EDACS system is on the 850-860 band, I know with a sound like this it really could be anything but I am hoping someone out there may have heard this before on an EDACS system or could lead me in the right direction

 

[62Truck]

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^ A sample of what occasionally happens to my SDS200 while scanning EDACS. It will do that with multiple antennas, it will drop conversations sometimes when it happens, it might linger for a little bit but the scanner will go right back to normal usually. The only other times this happens is when some UHF freqs bleed into each other but this has a more distinctive sound. This EDACS system is on the 850-860 band, I know with a sound like this it really could be anything but I am hoping someone out there may have heard this before on an EDACS system or could lead me in the right direction

Sounds like its getting overloaded. Have you tried turning on IFX, trying different filters, and turning on the attenuator?

I haven't experienced this on 800 or EDACS on my SDS200.

I do get some bleeding/intermod on 453.800 when 453.900 and a DMR frequency I haven't identified yet are active. The only thing that fixes that issue for me is turning on the attenuator on 453.800.

 

[Marauder]

Sounds like its getting overloaded. Have you tried turning on IFX, trying different filters, and turning on the attenuator?

I haven't experienced this on 800 or EDACS on my SDS200.

I do get some bleeding/intermod on 453.800 when 453.900 and a DMR frequency I haven't identified yet are active. The only thing that fixes that issue for me is turning on the attenuator on 453.800.

Good stuff, I get bleed and intermod on 453.800 CMD as well. Whichever fireground is 453.8500 gives it to me as well I will get a mix of cmd dispatch or response , whichever are both active at that moment, will change the ATT on and see if that helps for next time , thanks!

as for the actual main issue itself would it be getting overloaded by an SDR by chance? I know its RX only but I figure they put out some amount of RF like how radar detectors put out a little bit of RF and are detectable by radar detector detectors? lol

 

[62Truck]

Good stuff, I get bleed and intermod on 453.800 CMD as well. Whichever fireground is 453.8500 gives it to me as well I will get a mix of cmd dispatch or response , whichever are both active at that moment, will change the ATT on and see if that helps for next time , thanks!

as for the actual main issue itself would it be getting overloaded by an SDR by chance? I know its RX only but I figure they put out some amount of RF like how radar detectors put out a little bit of RF and are detectable by radar detector detectors? lol

I also have the same issue with 453.850.

How well do you receive the Sam's Point tower at your location?

Walker LCN 1 is 854.4125 and Sam's LCN 1 is 854.4625, they are pretty close in frequency which can cause some issues on the SDS. My theory is if you can hear Sam's Point as good as you can hear walker when Sam's 854.4625 is active and your SDS is listening to a transmission that is taking place on 854.4125 it could be causing the issue you're having.

 

[62Truck]

another could be Walker LCN 6 859.1125 and Beacon LCN 8 859.1875

Try and have your SDS display the freq and LCN if you don't already and see which LCN/freqs you're noticing this happening on

 

[GTR8000]

That's what happens when you build a $700 scanner around a $10 R836 tuner that was designed for wideband (6-8 MHz) television signals, where selectivity isn't a factor. That tuner is seeing everything within a 2.4 MHz window around the frequency it's tuned to, so even with Uniden's filters, there is always going to be some degree of crap overloading the chip. Attenuation may help, but that assumes that the signal is strong enough that you can enable attenuation without making the signal too weak to receive properly. It is what it is.

 

[trentbob]

That's what happens when you build a $700 scanner around a $10 R836 tuner that was designed for wideband (6-8 MHz) television signals, where selectivity isn't a factor. That tuner is seeing everything within a 2.4 MHz window around the frequency it's tuned to, so even with Uniden's filters, there is always going to be some degree of crap overloading the chip. Attenuation may help, but that assumes that the signal is strong enough that you can enable attenuation without making the signal too weak to receive properly. It is what it is.

I have to admit that is so true and attenuation doesn't help because nothing is close enough to still get through. It's just something I've noticed all along.

 

[GTR8000]

And just so that people don't take my post the wrong way, I'm not trashing the SDS series. They are quite good when it comes to 700/800 P25, especially when dealing with LSM/QPSK signals. That's where they really shine. But on the lower bands, especially in environments where there is a lot of RF in the air, they can struggle.

Just the other day I was comparing an SDS200 and 536HP side by side on an analog T-Band frequency, and the 536 outshined the SDS in both RF quality and audio quality. I was getting noticeable intermod on the SDS, whereas the 536 was quiet. Filters, IFX, ATT, etc. made no appreciable difference. Both scanners were connected to ProScan via LAN, so the audio was as good as it was going to get, but the 536 just sounded richer and fuller.

They both have their strong points and weak points. Whatever gets the job done.

 

[Marauder]

another could be Walker LCN 6 859.1125 and Beacon LCN 8 859.1875

Try and have your SDS display the freq and LCN if you don't already and see which LCN/freqs you're noticing this happening on

That is a good Idea, however, it just happened me on 858.0375. This only comes back to Walker. I use both sites Walker and Beacon, Walker for the extra TGs and Beacon for better connection when needed since closer. (Should note this issue happens on Beacon as well)
I also do not pick up anything besides Walker or Beacon here, ran them all.
Side note - I really miss having Port Ewen for the Kingston TGs , if only they simulcasted on Walker. I knew it wouldn't be useful practical or make sense in the real world but one can dream

And just so that people don't take my post the wrong way, I'm not trashing the SDS series. They are quite good when it comes to 700/800 P25, especially when dealing with LSM/QPSK signals. That's where they really shine. But on the lower bands, especially in environments where there is a lot of RF in the air, they can struggle.

Just the other day I was comparing an SDS200 and 536HP side by side on an analog T-Band frequency, and the 536 outshined the SDS in both RF quality and audio quality. I was getting noticeable intermod on the SDS, whereas the 536 was quiet. Filters, IFX, ATT, etc. made no appreciable difference. Both scanners were connected to ProScan via LAN, so the audio was as good as it was going to get, but the 536 just sounded richer and fuller.

They both have their strong points and weak points. Whatever gets the job done.

Both of your replies are extremely on point and appreciated. It is reassuring to know it is most likely not on my end personally.
I am no expert obviously but will say I am less than thrilled with the SDS on conventional, your point about low band and RF are extremely accurate as I have been trying to get Putnam county 153xxx and 46.36 on it forever. I do not have the most ideal setup situation so I generally will not get Putnam on the SDS unless VHF prop. is good and even if so it really is hard to hear. My BCT15X will pick up frequencies that the SDS200 are a ghost to or simply unreadable on, using the same antenna and same settings. Still not great sounding but extremely noticeably better especially if they weren't there at all on the SDS
I do agree very much with the P25 quality, it handles simulcast sites like a champ. CoRNet is butter and the MTA system decodes well 99 percent of the time.

 

[62Truck]

That is a good Idea, however, it just happened me on 858.0375. This only comes back to Walker. I use both sites Walker and Beacon, Walker for the extra TGs and Beacon for better connection when needed since closer. (Should note this issue happens on Beacon as well)
I also do not pick up anything besides Walker or Beacon here, ran them all.
Side note - I really miss having Port Ewen for the Kingston TGs , if only they simulcasted on Walker. I knew it wouldn't be useful practical or make sense in the real world but one can dream



Both of your replies are extremely on point and appreciated. It is reassuring to know it is most likely not on my end personally.
I am no expert obviously but will say I am less than thrilled with the SDS on conventional, your point about low band and RF are extremely accurate as I have been trying to get Putnam county 153xxx and 46.36 on it forever. I do not have the most ideal setup situation so I generally will not get Putnam on the SDS unless VHF prop. is good and even if so it really is hard to hear. My BCT15X will pick up frequencies that the SDS200 are a ghost to or simply unreadable on, using the same antenna and same settings. Still not great sounding but extremely noticeably better especially if they weren't there at all on the SDS
I do agree very much with the P25 quality, it handles simulcast sites like a champ. CoRNet is butter and the MTA system decodes well 99 percent of the time.

There are a few frequencies on NYCOMCO's system that are pretty close to 858.0375, Walker LCN 7 858.1125, Beacon LCN 7 858.1875, and Millbrook LCN 1 858.1375.

As GTR mentioned that the selectivity in the SDS series is pretty non existent, its going to see pretty much anything within 2.4mhz of the frequency you're tuned too.

On the frequencies you're getting the interference on as long as the signal on them is not weak I would turn on the attenuator and see if that makes things better or worse.

As for low band, I'm not sure of your location, but as I type I'm hearing 46.36 on my 200 using a UHF rubber duckie and I'm receiving it at -92dmb

 

[Marauder]

There are a few frequencies on NYCOMCO's system that are pretty close to 858.0375, Walker LCN 7 858.1125, Beacon LCN 7 858.1875, and Millbrook LCN 1 858.1375.

As GTR mentioned that the selectivity in the SDS series is pretty non existent, its going to see pretty much anything within 2.4mhz of the frequency you're tuned too.

On the frequencies you're getting the interference on as long as the signal on them is not weak I would turn on the attenuator and see if that makes things better or worse.

As for low band, I'm not sure of your location, but as I type I'm hearing 46.36 on my 200 using a UHF rubber duckie and I'm receiving it at -92dmb

Sorry about that I meant Putnam lowband 46.38, not dutchess 46.36. Dutchess 46.36 is indeed that strong for me as well. Will run the ATT for a while and see if it does anything , so far after an hour of trying not hearing much of a difference and the signal is showing weaker on the RSSI scale significantly, actually losing the sites entirely occasionally after enabling ATT

 

[tvengr]

Dumb question! Does your SDS200 have the ProVoice upgrade? A number of talkgroups (D in the Mode column) on the NYCOMCO EDACS system use ProVoice which your scanner cannot decode without the upgrade. Poughkeepsie uses AEGIS.

Dutchess County Law Enforcement

DEC	AFS	Mode	Alpha Tag	Description	Tag
457	03-091	A	DC 911 Police 1	911 Dispatch 1 (155.415)	Law Dispatch
469	03-105	A	DC 911 Police 2	911 Dispatch 2 (151.205)	Law Dispatch
447	03-077	A	DC Sheriff Dwntw	Sheriff Downtown Patrols Dispatch	Law Dispatch
453	03-085	A	DC Sheriff C-C	Sheriff Car to Car	Law Talk
417	03-041	D	DC Drug Task For	Drug Task Force	Law Tac
418	03-042	D	DC Drug Task For	Drug Task Force	Law Tac
419	03-043	D	DC Drug Task For	Drug Task Force	Law Tac
421	03-045	D	DC Drug Task For	Drug Task Force	Law Tac