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Possible to to go past 48k bandwidth in WFM

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w2rtv
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Possible to to go past 48k bandwidth in WFM

#1

Unread post by w2rtv »

Hello Simon,
is it possible you could bring the bandwidth of 48k in WFM mode up to 75 or 100k ? there is a new satellite up, Bobcat-1 and is
transmitting 57k6 data. 48k is not wide enough. BFM mode will not work.

73,
Rocky
W2RTV

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Simon G4ELI
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Re: Possible to to go past 48k bandwidth in WFM

#2

Unread post by Simon G4ELI »

Rocky,

Yes - but first please send me a good screenshot or better still an IQ (Data) recording, this will help a lot.
Simon Brown :shock:
www.sdr-radio.com

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w2rtv
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Re: Possible to to go past 48k bandwidth in WFM

#3

Unread post by w2rtv »

ok Simon ,i will get an I/Q recording and a screenshot to you when it goes back to 57k6.
thanks,
Rocky

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PD3LK
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Re: Possible to to go past 48k bandwidth in WFM

#4

Unread post by PD3LK »

In the past it was possible to add higher bandwiths, they still work fine here: 50/80/100/120/150 Khz but i can't copy/edit them anymore.
Rockey do you know if the D/L freq is 436.600 MHz?

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Simon G4ELI
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Re: Possible to to go past 48k bandwidth in WFM

#5

Unread post by Simon G4ELI »

w2rtv wrote:
Wed Nov 18, 2020 11:38 pm
ok Simon ,i will get an I/Q recording and a screenshot to you when it goes back to 57k6.
thanks,
Rocky
What I'll do is run at 48k if the filter is 48k or less, 96k if 96k or less or 128k if > 96k.

Should be easy, I'll just wait for the screenshot / IQ so I know what I'm dealing with.
Simon Brown :shock:
www.sdr-radio.com

Do not send me direct e-mail, thank-you!

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Simon G4ELI
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Re: Possible to to go past 48k bandwidth in WFM

#6

Unread post by Simon G4ELI »

Simon G4ELI wrote:
Thu Nov 19, 2020 7:02 am
w2rtv wrote:
Wed Nov 18, 2020 11:38 pm
ok Simon ,i will get an I/Q recording and a screenshot to you when it goes back to 57k6.
thanks,
Rocky
What I'll do is run at 48k if the filter is 48k or less, 96k if 96k or less or 128k if > 96k.

Should be easy, I'll just wait for the screenshot / IQ so I know what I'm dealing with.
I've just tried this logic with BFM - works well with three different sample rates. I'll add to WFM and post a kit today.
Simon Brown :shock:
www.sdr-radio.com

Do not send me direct e-mail, thank-you!

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Simon G4ELI
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Re: Possible to to go past 48k bandwidth in WFM

#7

Unread post by Simon G4ELI »

Simon G4ELI wrote:
Thu Nov 19, 2020 8:06 am

I've just tried this logic with BFM - works well with three different sample rates. I'll add to WFM and post a kit today.
Ah - isn't going to work. The audio output is always resampled to a constant 48kHz in my demodulation engine.
Simon Brown :shock:
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Simon G4ELI
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Re: Possible to to go past 48k bandwidth in WFM

#8

Unread post by Simon G4ELI »

So, the only solution is to add an optional extra for FM demodulation > 48kHz. Let me see the screenshot and IQ data please.
Simon Brown :shock:
www.sdr-radio.com

Do not send me direct e-mail, thank-you!

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w2rtv
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Re: Possible to to go past 48k bandwidth in WFM

#9

Unread post by w2rtv »

here is my dropbox link to I/Q /wav recording at 57k6
https://www.dropbox.com/s/yvfuwmy6bdj73 ... v.wav?dl=0

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w2rtv
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Re: Possible to to go past 48k bandwidth in WFM

#10

Unread post by w2rtv »

ok i am trying to post my dropbox link to recording. i hope it came through.
Rocky

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