Filter Bandwidth

[millam]

Is there a way to keep FMPA from changing the filter bandwidth. I want to keep the bandwidth at 7.6
continuously. I have a nexedge96 system that FMPA thinks is TDMA when filter bandwidth is above 7.6.
When FMPA switches to TDMA DSDPlus loses sync till it finds the CC again, over and over. -b-7.6 I guess
works in FMP24, have not tired that, think I will. Any troubleshooting ideas?

Mil

 

[millam]

FMP24 works at all filter bandwidths. FMPA works correctly on nexedge48 systems, but I
will check that. I only have 1 nexedge96 system I can hear.

Mil

 

[dave3825]

-b-7.6 I guess
works in FMP24, have not tired that, think I will.

For 7.6, it would be -b7.6, not -b-7.6

I don't have any Nexedge96 so all I can offer is what's listed in the FMP24 and FMPA.scanlist files. The tuner may default to what's shown below regardless of what switch is in your bat.. I seem to remember something from a while ago.

; Options:
;
; Modulation Specifier
;
; 4 kHz bandwidth digital protocol specifiers:
;
; iDAS
; NX48
; NXDN48
; NEXEDGE48
;
; 7.6 kHz bandwidth digital protocol specifiers:
;
; Dstar
; D-Star
; DMR
; TRBO
; Cap+
; Con+
; TIII
; XPT
;
; 9.5 kHz bandwidth digital protocol specifiers:
;
; Fusion
; NX96
; NXDN96
; NEXEDGE96
; P25
;
; 12.5 kHz bandwidth digital protocol specifiers:
;
; PV
; ProVoice
;
; Analog modulation specifiers:
;
; Anything else, such as "FM" or "Analog" or nothing
; is assumed to be FM modulated analog and defaults to 12.5 kHz bandwidth
;
;

 

[millam]

For 7.6, it would be -b7.6, not -b-7.6

I don't have any Nexedge96 so all I can offer is what's listed in the FMP24 and FMPA.scanlist files. The tuner may default to what's shown below regardless of what switch is in your bat.. I seem to remember something from a while ago.

Yea Dave -b-7.6 works for FMP24 but is illegal for FMPA. I was hoping someone had a work around for FMPA. Guess I'll have
to dig out another rtl sdr and go with FMP24 for this system.

Mil

 

[dave3825]

-b-7.6 works for FMP24 but is illegal for FMPA. I was hoping someone had a work around for FMPA.

And I guess this is a misprint in FMP24 help as it does not list a 7.6 as an option..
FMP24 Help says -b<kHz> Initial RF filter bandwidth (4, 7, 9.5, 12.5, 22) [-b7]

Anyway, I just looked at my fmp24 bat file that specifies -b12.5 and when it lands on a P25 Phase 2 cc, it defaults to 9.5.
Changing the switch to -b-12.5 overrides and keeps it on 12.5 on both cc and voice freqs.

On my airspy bat, -b12.5, when its on the cc it defaults to 9.5. When on a voice call, it switches to 12.5

Maybe email DSDPlus?

 

[millam]

Saw that Dave but nowhere else was 7 an option but 7.6 was. Probably missed it. Right
now on a single sdr it is staying put at 7.6 using -b-7.6 on the system in question. Has
anyone had DSDPlus respond to an email in the last year?

Mil

 

[dave3825]

I reported an issue related to using Fmp24.scanist on 7/29 and they responded 8/2.

 

[millam]

I reported an issue related to using Fmp24.scanist on 7/29 and they responded 8/2.

Gotcha, kinda thought they had went awol. Good to know they are still active. They have a good product.
Can't remember if am a life time subscriber or not, may just send them some money for thanks.

Mil

 

[CanesFan95]

I've always wished they would make FMPA let you tell it the bandwidth. This is a long-time known defect/flaw.

 

[millam]

I've always wished they would make FMPA let you tell it the bandwidth. This is a long-time known defect/flaw.

Thanks, I am glad its not me. If another nexedge96 system starts up near me I will see if its doing the same. Dug out
another rtl-sdr and edited by bat file to use FMP24 instead of FMPA for this system. Thanks yall;

Mil

 

[R0am3r]

On my airspy bat, -b12.5, when its on the cc it defaults to 9.5. When on a voice call, it switches to 12.5

I see this same behavior on my SDRplay RSP1A. When I start FMPP.exe with a specified bandwidth (e.g. -b7.6), it remains at that bandwidth until I start DSDPlus.exe. If DSDPlus.exe recognizes a P25 Phase 2 CC, it switches FMPP to the proper bandwidth of 9.5. When the tuner switches to a voice channel, the bandwidth jumps to 12.5 for that call.

I tested this behavior on a local NEXEDGE96 system. As expected, FMPP switched to a bandwidth of 9.5 for both the CC and the voice channels. The NEXEDGE96 system I am monitoring keeps the CC and switches to/from the voice channels properly.

IMHO - I like the intelligence the DSDPlus FL authors put into the software.

 

[millam]

I see this same behavior on my SDRplay RSP1A. When I start FMPP.exe with a specified bandwidth (e.g. -b7.6), it remains at that bandwidth until I start DSDPlus.exe. If DSDPlus.exe recognizes a P25 Phase 2 CC, it switches FMPP to the proper bandwidth of 9.5. When the tuner switches to a voice channel, the bandwidth jumps to 12.5 for that call.

I tested this behavior on a local NEXEDGE96 system. As expected, FMPP switched to a bandwidth of 9.5 for both the CC and the voice channels. The NEXEDGE96 system I am monitoring keeps the CC and switches to/from the voice channels properly.

IMHO - I like the intelligence the DSDPlus FL authors put into the software.

Yea I had no problem with it till this site started to decode as TDMA when using FMPA. Strange today I can't make
it decode TDMA. The only problem with DSDPlus setting filter bandwidth is that I have 2 sites that have very close
transmitters next to them, lots of errors unless I set the filter bandwidth lower. Ah nothing is perfect, just live with, HUH.

Mil

 

[millam]

Update: the nexedge96 site goes into TDMA decoding when the signal is above a certain level (?).
I can lower the gain until it quits TDMA and returns a normal signal. I had rotated my antenna 180
looking for another site and it worked, signal was weaker. It only happens on nexedge96 signals and
FMPA.exe program. I can live with this. Thanks for the inputs, bye.

Mil