NXDN Fine Tuning Help Request

Status
Not open for further replies.

UPMan

In Memoriam
Premium Subscriber
Joined
Apr 19, 2004
Messages
13,296
Location
Arlington, TX
Ok, we are working on making NXDN work better and to do so we need to fine tune some coding to better optimize digital audio recovery. The more data we can get, the better our results can be, so I'm putting out a "call to help" to you guys. Basically we need to manually determine the best decode threshold for NXDN 4800, 9600, and IDAS systems so that we can better determine the correct Auto threshold algorithm. I've set up a public Google sheet to log results at:

https://docs.google.com/spreadsheets/d/1enMeuXJAfvOA7KUkiWQ_k6a5uATOlw96KpIWnF5EhMk/edit?usp=sharing

Basically asking you to check decode error rate at every manual threshold setting, pick the setting that has the lowest error rate, and log that data into the spreadsheet. We (and all the other NXDN users) really appreciate any and all help you can provide.

Full instructions are in the sheet linked above.
 

mtindor

OH/WV DB Admin
Database Admin
Joined
Dec 5, 2006
Messages
10,370
Location
Carroll Co OH / EN90LN
Paul,

I honestly have never used the threshold / error facility before in the scanner. I'm expecting to see ERR information when i'm sitting on a site but I see nothing. Must there be active voice comms in order for this testing to be done?

Mike
 

Jay911

Silent Key (April 15th, 2023)
Feed Provider
Joined
Feb 15, 2002
Messages
9,378
Location
Bragg Creek, Alberta
Is it important for the receiver to be in a stationary position (i.e. not moving around) when the sampling is done?
 

jasonhouk

Member
Joined
Mar 29, 2013
Messages
883
Location
Marion, Ohio
Paul,

I honestly have never used the threshold / error facility before in the scanner. I'm expecting to see ERR information when i'm sitting on a site but I see nothing. Must there be active voice comms in order for this testing to be done?

Mike
Correct the error rate will only show on active voice decoding at this time.

Houk

Sent from my Moto G (4) using Tapatalk
 

UPMan

In Memoriam
Premium Subscriber
Joined
Apr 19, 2004
Messages
13,296
Location
Arlington, TX
Error rate shows during active voice decoding.

Stationary (I'm assuming by moving around you mean driving somewhere). Since the signal could change during a drive it could introduce false results caused by location-related issues (like interference at one place not present at another place).
 

jasonhouk

Member
Joined
Mar 29, 2013
Messages
883
Location
Marion, Ohio
Thanks, Jason. Domer NXDN is like Futronics CON+ -- dead. Argh.

m
REM in Columbus was dead last Friday night as well. Asked another RR user to get some activity Saturday (THE Ohio State University's Spring Game) there was activity then!

Houk

Sent from my Moto G (4) using Tapatalk
 

UPMan

In Memoriam
Premium Subscriber
Joined
Apr 19, 2004
Messages
13,296
Location
Arlington, TX
Sorry wereinshades. I realized when I saw your multiple results I had left out a step, so I just added it. Digital threshold mode should be Manual. You should only have a single result per system (whichever manual setting is best).
 

pinballwiz86

Member
Premium Subscriber
Joined
Jan 15, 2013
Messages
1,565
Location
Missouri
I'll add my numbers to the spreadsheet on Friday when I monitor some NXDN in St. Louis, MO.
 

kruser

Active Member
Premium Subscriber
Joined
Nov 25, 2007
Messages
4,987
Location
West St Louis County, MO
I'll add my numbers to the spreadsheet on Friday when I monitor some NXDN in St. Louis, MO.

Curious as to what system(s) you are planning on monitoring here?

I've been playing with the Warner system that claims to be for Barnes Hospitals but it is a hard one. Many of the unknown frequencies are in the UHF paging band so you can't search on the FCC site.

I've been trying to nail down the west county Barnes hospital that they are adding on to right now. It's on Olive a mile or two west of I-270.

The site called site 4 listed as in Oakville sure gives a strong signal here just a mile from the west county hospital so it could be listed in the DB in error. The sites antennas are still on the original buildings roof so barely above one floor.

I'm finding my Manual decode thresholds seem to favor manual levels of 10 or 11 for NXDN sites so far. Once I get a solid NXDN site programmed fully, I'll submit that to Paul's spreadsheet.
I can't really use the Barne's sites in the city as they are not really in range. I don't think the decode levels would be accurate for what Paul is after although all the weak signal NXDN systems I can hear are also decoding with the least errors when using a manual setting of 10 or 11.

NXDN seems opposite of the P25 sites which almost always like a manual level of 6. NXDN seems to favor the higher end of the setting range.
That seems to go with the three people that added data to the spreadsheet. I think they all listed a level of 10.
 

mtindor

OH/WV DB Admin
Database Admin
Joined
Dec 5, 2006
Messages
10,370
Location
Carroll Co OH / EN90LN
Looks like somebody went into the doc and accidentally changed everyone's "setting" to 10. I changed mine back to 7. Probably doesn't matter though since the Low/Mid/High values seem to be the same as when originally entered. Be careful though if you are adding your own, to only add your own and not modify anyone else's.

Mike
 

werinshades

Member
Premium Subscriber
Joined
Jan 21, 2002
Messages
5,818
Location
Chicago , IL
Sorry wereinshades. I realized when I saw your multiple results I had left out a step, so I just added it. Digital threshold mode should be Manual. You should only have a single result per system (whichever manual setting is best).

Sorry...just saw this. I'll do it again today. I misread this that you wanted us to post all results.
 
Last edited:

UPMan

In Memoriam
Premium Subscriber
Joined
Apr 19, 2004
Messages
13,296
Location
Arlington, TX
Also, please post a link to the system, not just the name. It is not always clear how to find the system in RRDB from just a brief name/description.

wereinshades: I left in one entry...and all your entries had (nearly) the same thresholds, so I left those in. Just need to know which setting was best.
 

UPMan

In Memoriam
Premium Subscriber
Joined
Apr 19, 2004
Messages
13,296
Location
Arlington, TX
Note: I'm also going to lock rows once they appear completed so that they can't be accidentally changed. Leaving system column unlocked, for now, so that links can be added if possible.

FLANO: Can you confirm that "10" is the correct setting? Doesn't match to the thresholds (might have been one that was inadvertently modified). If it is OK, I'll lock down that row.
 

FLANO

AZ DB Administrator
Database Admin
Joined
Dec 19, 2002
Messages
1,249
Location
SE of Tucson, AZ
Note: I'm also going to lock rows once they appear completed so that they can't be accidentally changed. Leaving system column unlocked, for now, so that links can be added if possible.

FLANO: Can you confirm that "10" is the correct setting? Doesn't match to the thresholds (might have been one that was inadvertently modified). If it is OK, I'll lock down that row.

I will re-do it this morning, in a few hours....oil change for the van :)
 

werinshades

Member
Premium Subscriber
Joined
Jan 21, 2002
Messages
5,818
Location
Chicago , IL
Also, please post a link to the system, not just the name. It is not always clear how to find the system in RRDB from just a brief name/description.

wereinshades: I left in one entry...and all your entries had (nearly) the same thresholds, so I left those in. Just need to know which setting was best.

Yes...I added it this morning...10
 

kruser

Active Member
Premium Subscriber
Joined
Nov 25, 2007
Messages
4,987
Location
West St Louis County, MO
Looks like somebody went into the doc and accidentally changed everyone's "setting" to 10. I changed mine back to 7. Probably doesn't matter though since the Low/Mid/High values seem to be the same as when originally entered. Be careful though if you are adding your own, to only add your own and not modify anyone else's.

Mike

I wondered about that when I looked at the doc last night. I knew the readings on at least yours were 7 like you said. Then when I looked later, all 10's.
 

cg

Member
Premium Subscriber
Joined
Dec 13, 2000
Messages
4,579
Location
Connecticut
For the 536, it is Function then volume knob to get into the settings.

A couple qualifications about the system I entered:
- The NXDN48 system I can hear, PVTA Pelham, MA (not in the database) is about 35 miles away.
- I don't even get a lock on the NXDN mode below 8 or above 12
- Two voice frequencies are used in rotation after each PTT. One is better than the other, results are based on the better frequency.

chris
 
Status
Not open for further replies.
Top