FM right now.
Test for P25 Decode Improvement
- Thread starter UPMan
- Start date
- Status
FM right now.
Indiana Project Hoosier SafeT
St. Joseph Simulcast
Condition before: Fair
Condition after: Fair
Still seems to pull systems well where it did before at home, but after NFM to FM it misses TXs. During travel through the middle of the site it is pretty much the same as before with high error rates and dropped txs but signal is strong. Still appreciate the idea though.
St. Joseph Simulcast
Condition before: Fair
Condition after: Fair
Still seems to pull systems well where it did before at home, but after NFM to FM it misses TXs. During travel through the middle of the site it is pretty much the same as before with high error rates and dropped txs but signal is strong. Still appreciate the idea though.
I think I'm going to go against the grain here. I have had my feed (Frederick County Airport, Highway, Police, Fire and EMS) set to FM for a few hours today. And also set to NFM for a few hours. I'm 99.5% sure that decoding is better (for me) in NFM mode.
Let me tell you a bit about my situation. My scanner sits dead center of two close towers. One 3 miles in that direction and the other just under 3 miles in the exact opposite direction. The 536HP is definitely decoding P25 far better than my 996XT. But still is not perfect. I switched the FM today based on this thread and I believe it actually worsened. Its back to NFM now and it sounds better. If I had to rate the two modes 1 through 10. 1 being bad and 10 being perfect audio....
FM = 4
NFM = 6
I'll try this test again tomorrow. Sorry if this input is the opposite of what you wanted to hear.
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- Nov 19, 2008
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This is for a Motorola Type II system.
Well I took some advice and followed the directions on setting the modulation to FM. Then setting the P25 Threshold Mode to MANUAL. Then setting the P25 Threshold Level to 10.
Once I made all of these manual changes I am getting GREAT results. I use to get an error rate of about 70 to 80 and now I get errors rates between 20-30 with no choppy transmissions at all.
Sounds Pretty Good. Some good old fashion manual settings makes the radio sound good.
Well I took some advice and followed the directions on setting the modulation to FM. Then setting the P25 Threshold Mode to MANUAL. Then setting the P25 Threshold Level to 10.
Once I made all of these manual changes I am getting GREAT results. I use to get an error rate of about 70 to 80 and now I get errors rates between 20-30 with no choppy transmissions at all.
Sounds Pretty Good. Some good old fashion manual settings makes the radio sound good.
Update for format:
System: Arkansas Wireless Information Network (AWIN) Trunking System, Statewide, Multi-State - Scanner Frequencies
Site: Little Rock Metro Simulcast Site Details (Arkansas Wireless Information Network (AWIN))
Before: Excellent
After: Good
- Joined
- Aug 1, 2011
- Messages
- 948
- Reaction score
- 75
http://www.radioreference.com/apps/db/?sid=3918
Hopewell Site – 3 bars Signal Strength Solid
Condition before: Excellent
Condition after: Excellent
Hopewell Site – 3 bars Signal Strength Solid
Condition before: Excellent
Condition after: Excellent
Ohio MARCS-IP: Multi-Agency Radio Communications (P25)
Ohio MARCS-IP: Multi-Agency Radio Communications (P25) Trunking System, Various, Ohio - Scanner Frequencies
001 Cuyahoga simulcast
Before: Poor-Good
After: Good-Excellent
Ohio MARCS-IP: Multi-Agency Radio Communications (P25)
Ohio MARCS-IP: Multi-Agency Radio Communications (P25) Trunking System, Various, Ohio - Scanner Frequencies
007 Elyria
Before: Good
After: Excellent
Greater Cleveland Radio Communications Network
Greater Cleveland Radio Communications Network Trunking System, Cleveland, Ohio - Scanner Frequencies
001 Cleveland Simulcast
Before: Poor-Good
After: Good-Excellent
Ohio MARCS-IP: Multi-Agency Radio Communications (P25) Trunking System, Various, Ohio - Scanner Frequencies
001 Cuyahoga simulcast
Before: Poor-Good
After: Good-Excellent
Ohio MARCS-IP: Multi-Agency Radio Communications (P25)
Ohio MARCS-IP: Multi-Agency Radio Communications (P25) Trunking System, Various, Ohio - Scanner Frequencies
007 Elyria
Before: Good
After: Excellent
Greater Cleveland Radio Communications Network
Greater Cleveland Radio Communications Network Trunking System, Cleveland, Ohio - Scanner Frequencies
001 Cleveland Simulcast
Before: Poor-Good
After: Good-Excellent
Michigan's Public Safety Communications System (MPSCS) Trunking System, Statewide, Multi-State - Scanner Frequencies MPSCS Michigan
Sites: Northville, Munith and Howell
Condition before: Excellent
Condition after: Excellent
However all of my muffled talk groups when set on NFM are now acceptable to very good on FM. So it has cleared up the Audio quality for this system.
__________________
Sites: Northville, Munith and Howell
Condition before: Excellent
Condition after: Excellent
However all of my muffled talk groups when set on NFM are now acceptable to very good on FM. So it has cleared up the Audio quality for this system.
__________________
ButchGone
Member
Tennessee Valley Regional Communications System, Phase 1 & Phase 2, Chattanooga Simulcast site. (This system is linked into TACN)
Tennessee Advanced Communications Network (TACN) Trunking System, Varies, Multi-State - Scanner Frequencies
Switching from NFM to FM made decode worse.
Decode optimal when NFM, 12.5kHz.
Noted noise from nearby cell towers choked desired signals when FM 25 kHz, but in NFM 12.5 kHz i get little, if any cell tower interference.
BG..
Tennessee Advanced Communications Network (TACN) Trunking System, Varies, Multi-State - Scanner Frequencies
Switching from NFM to FM made decode worse.
Decode optimal when NFM, 12.5kHz.
Noted noise from nearby cell towers choked desired signals when FM 25 kHz, but in NFM 12.5 kHz i get little, if any cell tower interference.
BG..
FORMAT FOR REPORTING (to make my life a little easier):
Link to the system in RRDB.
Specific site monitored (if known).
Condition before: Excellent / Poor
Condition after: Excellent / Poor
https://www.radioreference.com/apps/db/?sid=7128
Simulcast (unknown)
Condition before: Good, some degradation at times, mostly evenings
Condition after: Worse, DAT kept going off/on. Switched back.OK
Mike DeMeo
W2MDN
Link to the system in RRDB.
Specific site monitored (if known).
Condition before: Excellent / Poor
Condition after: Excellent / Poor
https://www.radioreference.com/apps/db/?sid=7128
Simulcast (unknown)
Condition before: Good, some degradation at times, mostly evenings
Condition after: Worse, DAT kept going off/on. Switched back.OK
Mike DeMeo
W2MDN
BCD536HP/BCD436HP Test for P25 Decode Improvement
Michigan's Public Safety Communications System (MPSCS) Trunking System, Statewide, Multi-State - Scanner Frequencies
Site: Holly Tower
Condition before: Good
Condition after: Excellent
Watching the error rate on NFM it goes between 0-11when set to FM it goes between 0-2 and the Audio sound better set to FM.
Mike
Michigan's Public Safety Communications System (MPSCS) Trunking System, Statewide, Multi-State - Scanner Frequencies
Site: Holly Tower
Condition before: Good
Condition after: Excellent
Watching the error rate on NFM it goes between 0-11when set to FM it goes between 0-2 and the Audio sound better set to FM.
Mike
Last edited:
mikeshepard
Member
San Diego County - Imperial County Regional Communications System (RCS
South Simulcast
Before: Poor
After: Poor
South Simulcast
Before: Poor
After: Poor
4482
Member
SITE MONITORED FROM HOME: Greater Cleveland Radio Communications Network
CONDITION BEFORE WITH NFM: Poor to good
CONDITION WITH CHANGE TO FM: Much worse in performance
I have simulcast issues from from my home. My new BCD536HP copies the network above poor to good, whereas neither my PSR-800 or my PRO-197 will copy the system at all.
CONDITION BEFORE WITH NFM: Poor to good
CONDITION WITH CHANGE TO FM: Much worse in performance
I have simulcast issues from from my home. My new BCD536HP copies the network above poor to good, whereas neither my PSR-800 or my PRO-197 will copy the system at all.
doctordave
Member
- Joined
- Jan 2, 2003
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- 1,562
- Reaction score
- 0
BALTIMORE COUNTY MD - PHASE 1 SIMULCAST
Baltimore County Trunking System, Various, Maryland - Scanner Frequencies
Site: South (the primary site for the county)
Before: VERY GOOD
After: FAIR
Discussion: Test conducted in a high RF environment ( cellular/NEXTEL density, nearby jurisdictions on 800mhz that are well copied from here) - so I'm actually not surprised that FM mode diminished performance - -likely a result, in part, of significant adjacent channel interference that developed while "grabbing" a wider piece of spectrum.
Baltimore County Trunking System, Various, Maryland - Scanner Frequencies
Site: South (the primary site for the county)
Before: VERY GOOD
After: FAIR
Discussion: Test conducted in a high RF environment ( cellular/NEXTEL density, nearby jurisdictions on 800mhz that are well copied from here) - so I'm actually not surprised that FM mode diminished performance - -likely a result, in part, of significant adjacent channel interference that developed while "grabbing" a wider piece of spectrum.
Update report
Orange County (California) CCCS
N, NW, S, SW, Countwide Sites P25 decoding
NFM Poor
FM with P25 manual 10 Quite good
Steve AA6IO
Orange County (California) CCCS
N, NW, S, SW, Countwide Sites P25 decoding
NFM Poor
FM with P25 manual 10 Quite good
Steve AA6IO
Here are a few from the Los Angeles basin:
Los Angeles City (STRS - Simulcast Trunked Radio System) Project 25 Trunking System, Los Angeles, California - Scanner Frequencies
Site 8
Before: Poor/Moderate
After: Moderate
Site 1:
Before:Moderate
After: Good
Audio appears to sounds louder with FM
Los Angeles World Airports (LAWA) Trunking System, Los Angeles, California - Scanner Frequencies
Site 1:
Before: Excellent
After: Excellent
Interagency Communications Interoperability System (ICIS): Project 25 Trunking System, Los Angeles County, California - Scanner Frequencies
Site: 16
Before: Moderate
After: Moderate
In summary, I did not notice any huge changes, though going to FM from NFM certainly did not degrade the performance.
Los Angeles City (STRS - Simulcast Trunked Radio System) Project 25 Trunking System, Los Angeles, California - Scanner Frequencies
Site 8
Before: Poor/Moderate
After: Moderate
Site 1:
Before:Moderate
After: Good
Audio appears to sounds louder with FM
Los Angeles World Airports (LAWA) Trunking System, Los Angeles, California - Scanner Frequencies
Site 1:
Before: Excellent
After: Excellent
Interagency Communications Interoperability System (ICIS): Project 25 Trunking System, Los Angeles County, California - Scanner Frequencies
Site: 16
Before: Moderate
After: Moderate
In summary, I did not notice any huge changes, though going to FM from NFM certainly did not degrade the performance.
Sorry guys couldnt find where to edit this post. I actually went into favorite group settings and changed the site to FM and now it shows FM when it hits on talkgroups (so following UPmans route through the settings may not have been changing mine because I'm monitoring my simulcast site as a favorite and not by the "full database") But it still doesnt make a big difference...alone
However changing the p25 system to manual and threshold to 10 combined with FM dare I say its 90% as good as my 396xt which is pretty darn good when this audio sounds better IMHO. It is still showing error rates in the 30's and 40's but if I didnt see the rates I would guess under 15 just by listening to it. I'm still not sure if its missing tx's but I'll listen some more.
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