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MD2SAW > PACKET 02.08.21 11:00l 217 Lines 7581 Bytes #999 (0) @ WW
BID : 3570_MD2BBS
Read: GAST DQB562
Subj: Re: Direwolf FixBit DE/ENG
Path: DBO595<DBX320<BLM274<CB0ESN<FU0BOX<KS1BBS<HEJ717<VB1BOX<MD2BBS
Sent: 210802/0918Z @:MD2BBS.#SAW.SAA.DEU.EU #:3570 [Salzwedel] $:3570_MD2BBS
From: MD2SAW@MD2BBS.#SAW.SAA.DEU.EU
To : PACKET@WW
Am 02.08.21 um 11:35 schrieb MD2SAW:
> Am 01.08.21 um 22:19 schrieb NL1VKL:
>> Path: !VB1BOX!NL3VKL!
>>
>> From: NL1VKL@NL3VKL.NBO.NLD.EU
>> To : PACKET@WW
>>
>> Message from: NL1VKL@NL3VKL
>>
>> Quoting from a previous message...
>>
>>>
>>> English:
>>>
>>> Hi folks(Hoi, mensen),
>>>
>>> here is another possibility to let Direwolf decode better which might
>>> enable or improve the reception of more distant stations.
>>>
>>> Set the option "FIC_BITS" in your config file to 1 or higher.
>>> So:
>>> FIX_BITS 1
>>>
>>> If this option is enabled, Direwolf tries to swap a bit back and forth
>>> in not correctly received messages until the message matches the
>>> checksum again.
>>>
>>> Depending on the value set, i.e.
>>> FIX_BITS 1,
>>> FIX_BITS 2,
>>> FIX_BITS 3,
>>> ...,
>>> DW tries to exchange the number of bits.
>>> The whole thing goes naturally to load of the CPU.
>>>
>>> I use the option FIX_BITS 3 and run 2 instances of DW on a Raspberry PI
>>> 4 with 2 external soundcards plus Noden software (TNN) and other programs.
>>> The PI does a great job.
>>> Per instance DW about 10 percent CPU load in the peak.
>>> I have additionally activated the FX.25 encoding in DW which should also
>>> generate some CPU load.
>>>
>>> Greetings from Salzwedel,
>>>
>>
> Hi,
>
> Direwolf's FIX_BITS isn't really a good option to decode better. It can, and
> does, corrupt data by the nature of its design/principle
>
> It's actually not a good option to use at all and it's better to set
> FIX_BITS to 0 and only enable FX.25.
>
> 73! Dave de NL1VKL
>
> ====================================================================
> _____ __ ___ _____ _____ __
> | | | | |_ | | | | | | | Sysop: Dave
> | | | | |__ _| |_| | | -| |__ QTH: Uden - JO21TP
> |_|___|_____|_____|\___/|__|__|_____| BBS: NL3VKL.NBO.NLD.EU
> QRV: 27.235 MHz (FM 1k2)
> 27.365 MHz (LSB 1k2)
> NL3VKL BBS
> NL5VKL Net/Rom node / internet gateway https://nl5vkl.mijndingen.nl
> ====================================================================
> ** This message is generated with Sally 7.2.044
> -----------------------------------------------------------------
>
> Deutsch:
>
> Hallo,
>
> Direwolfs FIX_BITS ist nicht wirklich eine gute Option, um besser zu
> dekodieren. Es kann, und
> Daten aufgrund der Natur ihres Designs/Prinzips korrumpieren.
>
> Es ist eigentlich keine gute Option, die man verwenden sollte, und es
> ist besser,
> FIX_BITS auf 0 zu setzen und nur FX.25 zu aktivieren.
>
> 73! Dave de NL1VKL
>
> ====================================================================
> _____ __ ___ _____ _____ __
> | | | | |_ | | | | | | | Sysop: Dave
> | | | | |__ _| |_| | | -| |__ QTH: Uden - JO21TP
> |_|___|_____|_____|\___/|__|__|_____| BBS: NL3VKL.NBO.NLD.EU
> QRV: 27.235 MHz (FM 1k2)
> 27.365 MHz (LSB 1k2)
> NL3VKL BBS
> NL5VKL Net/Rom node / internet gateway https://nl5vkl.mijndingen.nl
> ====================================================================
> ** This message is generated with Sally 7.2.044
> -----------------------------------------------------------------
>
Deutsch:
Hi und danke für die Information.
Du hast natürlich recht damit das durch FIX_BITS die Pakete teilweise
nicht zu 100% wieder hergestellt werden koennen, diese "kaputten" Pakete
aber trotzdem an die jeweilige Software weitergeleitet werden, was in
manchen Fällen zu Problemen führen kann.
Man kann Direwolf aber nach FIX_BITS noch eine Ueberpruefung der Pakete
vornehmen lassen was aber auch kein Garant fuer korrekte Daten ist.
Mit
FIX_BITS 1 AX25
checkt DW den AX25 Adressbereich nach Plausibilitaet und mit
FIX_BITS 1 APRS
checkt DW ob es sich um ein plausibles APRS Paket handelt.
Was FX.25 und FIX_BITS angeht, so sieht es so aus als ob FIX_BITS bei
FX.25 Paketen nicht verwendet wird.
Normales Paket ohne FX.25:
DNX527 audio level = 41(14/9) [NONE] _|||||___
an dem [NONE] ist zu erkennen das FIX_BITS aktiviert ist.
[NONE] - Don't try to repair.
[SINGLE] - Attempt to fix single bit error. (default)
[DOUBLE] - Also attempt to fix two adjacent bits.
[TRIPLE] - Also attempt to fix three adjacent bits.
[TWO_SEP] - Also attempt to fix two non-adjacent (separated) bits.
FX25 Paket:
DX0SAW audio level = 54(15/10) 000007___
Hier sind keine FIX_BITS "Labels" ( [....] ) mit angegeben was mich
darauf schliessen laesst das hier kein FIX_BITS angewendet wird.
Es kommt natuerlich auf den Anwendungsbereich an.
Betreibe ich eine BBS die forward via HF macht oder nutze ich ein
NET/ROM Link koennte FIX_BITS eher kontraproduktiv sein.
Aber ich selber habe keine schlechten Erfahrungen damit gemacht bisher
obwohl ich auch forwarde via HF und auch ein NET/ROM Link via HF
eingerichtet hab.
Ich kann nur sehen das mir FIX_BITS hin und wieder Pakete "rettet".
In wie fern sie korrumpiert waren kann ich nicht sagen.
Gruesse,
_________________________________________________________________________
English:
hi and thanks for the information.
You are of course right that FIX_BITS can not restore the packages to
100%, but these "broken" packages are still forwarded to the respective
software, which can lead to problems in some cases.
But you can let Direwolf check the packages after FIX_BITS, but this is
no guarantee for correct data.
With
FIX_BITS 1 AX25
DW checks the AX25 address range for plausibility and with
FIX_BITS 1 APRS
DW checks if it is a plausible APRS packet.
Concerning FX.25 and FIX_BITS, it looks like FIX_BITS is not used for
FX.25 packets.
Normal packet without FX.25:
DNX527 audio level = 41(14/9) [NONE] _|||||___
the [NONE] indicates that FIX_BITS is enabled.
[NONE] - Don't try to repair.
[SINGLE] - Attempt to fix single bit error. (default)
[DOUBLE] - Also attempt to fix two adjacent bits.
[TRIPLE] - Also attempt to fix three adjacent bits.
[TWO_SEP] - Also attempt to fix two non-adjacent (separated) bits.
FX25 package:
DX0SAW audio level = 54(15/10) 000007___
Here are no FIX_BITS "labels" ( [....] ) given which leads me to believe
that no FIX_BITS is applied here.
It depends of course on the area of application.
If I run a BBS that does forward via HF or if I use a NET/ROM link
FIX_BITS could be rather counterproductive.
But I have no bad experiences with it so far although I also forward via
HF and also have a NET/ROM link via HF set up.
I can only see that FIX_BITS "saves" packages from time to time.
In how far they were corrupted I can't say.
Greetings,
Translated with www.DeepL.com/Translator (free version)
--
73 Manuel.
=========================================================================
__ __ ____ ____ ____ ___ __
| \/ | _ \___ \/ ___| / \ \ / / Sysop: Manuel
| |\/| | | | |__) \___ \ / _ \ \ /\ / / QTH: Salzwedel - JO52NU
| | | | |_| / __/ ___) / ___ \ V V / BBS: MD2BBS.#SAW.SAA.DEU.EU
|_| |_|____/_____|____/_/ \_\_/\_/ QRV: 27.235 MHz / 27.025 MHz
PR-Mail: MD2SAW@MD2BBS.#SAW.SAA.DEU.EU
E-MAil: cb0saw@e-mail.de
Terminal: MD2SAW via CB0SAW
CB0SAW Teamspeak3-/I-Net-/HF-Gateway/I-Gate AXIP:185.180.196.36 U 18093
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