Reducing Bandwidth for better RADE performance

Alan Beard

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Jan 25, 2026, 5:18:40 AM (3 days ago) Jan 25

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I can change the bandwidth for the SSB decoder in the WebSDR here.

What settings are recommended?

Currently 200 to 2800 Hz, Can I reduce this and improve the small signal

l

performance?

Alan VK2ZIW

Rick, W4XA

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Jan 25, 2026, 11:57:41 PM (2 days ago) Jan 25

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Hi Alan,

I use 1.5kHz (BW) for receive and 500-2000 Hz tx with my IC705

73/Rick

Rick, W4XA

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Jan 26, 2026, 12:33:03 AM (2 days ago) Jan 26

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Correction: 500-2500Hz with SSB-D for the IC705 tx bandwidth (2000Hz)

Stefan N.

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Jan 26, 2026, 3:41:31 AM (2 days ago) Jan 26

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750-2250 Hz would give you the intended 1.5KHz of the RX Signal. Often a problem to (easy) setup this on non SDR Radio's, if you use SSB for FreeDV, like i do on the 991a.

It’s easy to adjust that on WebSDR‘s (and SDR Radios) and helps, if you want to cut of QRM below, or above the 1.5Khz FreeDV „mainstream“.

73, Stefan

Alan Beard

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Jan 26, 2026, 5:47:02 AM (2 days ago) Jan 26

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I've reduced the bandwidth to 700 to 2300Hz and decode seems as good as before.

Nepean Mens Shed SDR

Alan VK2ZIW

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Rick, W4XA

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Jan 27, 2026, 2:49:05 AM (yesterday) Jan 27

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Yeah. It would. 500-2500 is the SSB-D selectable limit on the IC705. Don't know about the IC7300 or other radios.

Alan Beard

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3:48 AM (3 hours ago) 3:48 AM

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Stations heard with this new setting, 700 to 2300 Hz, over an hour of QSOs.

VK3FAR VK3AOB VK2VCO VK3AOB VK2VCO VK3AOB VK3AOB VK2VCO VK3FAR
VK3FAR VK3AOB VK3FAR VK3FAR VK3SRC VK3FAR VK3SRC VK3FAR VK3SRC
VK3FAR VK3SRC VK3FAR VK3SRC VK3FAR VK3SRC VK3FAR VK3SRC VK3FAR
VK3SRC VK3AOB VK3AOB VK3AOB VK3AOB VK2VCO VK3AOB VK2VCO VK3AOB
VK2VCO VK3AOB VK3AOB VK3AOB VK2AWJ

This is from the freedv-ka9q log.

Alan VK2ZIW

Stefan N.

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5:58 AM (1 hour ago) 5:58 AM

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Rick,

Non-SDR radios usually only have 'presets'. I use the settings mentioned (750–2250) for the TX/RX bandwidth on my Flex6400M.

I can set any bandwidth with 1 Hz accuracy, which is very helpfull in this case of course ;-)

It might be helpful to discuss this topic via Internetreporter Chat? I feel that accessibility via this forum is quite limited?

BTW, unfortunately, it is also difficult to communicate to the majority that the "calling frequencies" should not be used for long QSOs or networks, which has already been discussed here.