SDS200 - Best Filter selection for Simulcast P25 Phase 1

[rvacs]

Hello All,

Battling a little with reception right now...sure I will get this resolved with a better antenna.
I know a lot of people have different needs for the "FILTER" setting.

Just curious what most use for a Simulcast P25 Phase 1 system.
Options for the site are:
GLOBAL (Default)
Normal
Invert
Auto
Wide Normal
Wide Invert
Wide Auto
Off (This is what I am currently on).

** Seems my reception is a tad bit better on OFF. But if we think it may be better decode on another let me know.
I have been using Analyze System to check Signal (S) and Decode (Q).

Also love to hear of any suggestions on inside antenna that has worked for others over the telescopic.

THANK YOU !!

 

[jonwienke]

The best filter setting depends on whether potentially interfering signals are above or below the frequency you're trying to receive, and how far. So the best settings for you will vary by frequency, and other people's best settings are irrelevant.

 

[n1chu]

I have found it’s a case of “Your Results may Vary”. Meaning you should try different filter settings and go with the best. Don’t expect to be able to differentiate between filters either... if the signal is strong it just may be no one setting is found to be better. Try a setting and compare to “Off”. If you see a difference, go with it. If not, leave settings off. This applies to a home base station where the antenna never moves. All bets are off for portable and mobile use.

 

[werinshades]

I own 2-SDS200's and have been using the Attenuator on a statewide 700mhz. system. I also have a conventional P25 700mhz system that this was needed too. In addition Wide Invert appears to work best in my location.

 

[KG6GTH]

What about for Analog Conventional and P25 Conventional???

 

[werinshades]

What about for Analog Conventional and P25 Conventional???

Change modulation to FM on analog conventional, change volume offset to +2 or+ 3 to compensate for audio. What problem are you having on P25 conventional?

 

[Bolt21]

My theory (for the SDS100 - same filters) is that if you're stationary, find the filter that produces the lowest error rates/least garbled audio. If you're mobile, use the Auto or Wide-Auto filter to compensate for any varying interference that you may encounter during your travels. Don't know if this is the correct theory, but it's the best that I can come up with that works for me.

For me, best reception for P25 P1 systems is with Wide-Inv while stationary and Wide-Auto while mobile. And it's also worth mentioning that I have not found a filter that prevents missed transmissions every once in a while. While the SDS is a huge improvement with simulcast over the previous Unidens, they are not perfect, and that is to be expected, I guess.

 

[n1chu]

My theory (for the SDS100 - same filters) is that if you're stationary, find the filter that produces the lowest error rates/least garbled audio. If you're mobile, use the auto/wide auto filter to compensate for any varying interference that you may encounter during your travels. Don't know if this is the correct theory, but it's the best that I can come up with that works for me.

For me, best reception for P25 P1 systems is with Wide-Inv while stationary and Wide-Auto while mobile. And it's also worth mentioning that I have not found a filter that prevents missed transmissions every once in a while. While the SDS is a huge improvement with simulcast over the previous Unidens, they are not perfect, and that is to be expected, I guess.

I think it’s always been the case that missing some calls are part of the game. All scanners miss calls or parts of calls by design. But with the scan rates we enjoy today we can reasonably expect to capture most.

The only way we can guarantee no missed calls or parts of calls is to dedicate a radio to a frequency or talk-group and do not allow it to scan other agencies. But we could dedicate older scanners to “Hold” on a channel permanently. Get enough receivers/scanners set up during a multiple agency call and you’ve got quite a Party!

 

[Bolt21]

The only way we can guarantee no missed calls or parts of calls is to dedicate a radio to a frequency or talk-group and do not allow it to scan other agencies.

I routinely miss transmissions, even when holding on a specific TG. Just part of it. Anyways, didn't mean to derail the thread topic of filters...

 

[rvacs]

@werinshades - you said -

Change modulation to FM on analog conventional, change volume offset to +2 or+ 3 to compensate for audio. What problem are you having on P25 conventional?

How do I know if it is Analog or Digital? I think its Digital - but not sure system tells me. It is the Greater Austin Regional Radio System (GATTRS) - Greater Austin/Travis Regional Radio System (GATRRS) Trunking System, Austin, Texas - Scanner Frequencies

 

[nessnet]

.... use the Auto or Wide-Auto filter to compensate for any varying interference that you may encounter during your travels.

Use auto if you want to s l o w your scanning rate waaay down. I wouldn't recommend it.

 

[hiegtx]

@werinshades - you said -

How do I know if it is Analog or Digital? I think its Digital - but not sure system tells me. It is the Greater Austin Regional Radio System (GATTRS) - Greater Austin/Travis Regional Radio System (GATRRS) Trunking System, Austin, Texas - Scanner Frequencies

GATRRS is digital.

Any system with a system type listed as 'Project 25', regardless of whether it's Phase I & II, is digital. You may also see systems that are Motorola Type II, but 'system voice' includes 'APCO 25'. Those may be using only digital, or a mix of both digital and analog talkgroups.


The volume offset can be used on any talkgroup, regardless of whether it is digital or analog.

For a trunked system, the modulation settings (auto, FM, or NFM) for non-P25 systems can set for each site. For P25 systems, Phase I or Phase II, the setting is set automatically, and cannot be edited.

 

[n1chu]

I routinely miss transmissions, even when holding on a specific TG.

Thats why I included the term “dedicated radio”. When it’s listening it don’t miss a thing! But I wonder why you are missing stuff if you have it locked down on a specific TG? And you are accepting it as “It is what it is”? Has Uniden given you the impression these drop-outs are to be expected? I don’t doubt you. Just wondering if I missed Uniden documentation that says we should accept these occasional drop-outs on occasion, even when locked down on a TG.

 

[jonwienke]

Just wondering if I missed Uniden documentation that says we should accept these occasional drop-outs on occasion, even when locked down on a TG.

If you read the Uniden documentation, you'll discover that the scanner will scan all sites in range, even when holding on a talkgroup. If you don't want to miss anything, you have to hold on the TG and on a system site that carries it.

 

[n1chu]

That’s what I was led to believe. So, I take from from your post if I have the scanner locked down on a specific TG I shouldn’t experience drop-outs... apparently just accepting drop-outs as “It’s the nature of the beast”, meaning scanners, is incorrect. Thank you for the guidance.

 

[kruser]

That’s what I was led to believe. So, I take from from your post if I have the scanner locked down on a specific TG I shouldn’t experience drop-outs... apparently just accepting drop-outs as “It’s the nature of the beast”, meaning scanners, is incorrect. Thank you for the guidance.

If the TG traffic you want is not carried on all sites, you still risk missing traffic as the scanner checks the other sites for traffic.
Holding on the specific TG and Site that carries the TG will provide the best chance at not missing traffic as jonwienke explained.

 

[rvacs]

Thanks @hiegtx and @n1chu for your help.
I figured it was digital - thank.

@kruser - I am only scanning 6 talk group dispatch channels. And only using the tower those 6 talkgroups are on.

I have ordered a directional yagi to see if I can get my S (signal) improved.
It usually hovers around 1/3 height on scale and Q (quality) is at the top. But missing lots of conv. my G5 picks up with no problem with its little antenna right near it (scanning same site and same talkgroups). If I can get my signal better for the SDS think I will be golden.

 

[werinshades]

If the TG traffic you want is not carried on all sites, you still risk missing traffic as the scanner checks the other sites for traffic.
Holding on the specific TG and Site that carries the TG will provide the best chance at not missing traffic as jonwienke explained.

After reading many posts on these threads, I don't think some here understand how trunking systems work, what the scanner has to do with control channel sites etc. This is especially true with larger and statewide systems. I scan 2 sites from home that are within my range, both sites carry almost identical traffic with the exception of a handful of talkgroups. In addition, I also "scan" with my scanner many other systems..mish mosh of analog, trunking etc. Had to respond so you know your post didn't fall on deaf ears...lol!

 

[Bolt21]

Use auto if you want to s l o w your scanning rate waaay down. I wouldn't recommend it.

With conventional channels, yes. With trunked systems, scanning one site at least, I don't see any noticeable difference. If the control channel is directing the scanner to the proper LCN, how much "scanning" is really being done, and how much can it really be slowed by Auto?

 

[alphaacres]

I use the RSSI to find the best filter just look in Proscan history log and you will see the difference lower RSSI numbers is better mine is wide normal for the P25 system I listen to.