FreeDV - bandwidth settings

Tom Porada

I realized while using FreeDV that the actual signal within the 3K DIGU/DIGL bandwidth runs from 700 to 2300 hz.

On the transmit side (with a Profile) I set a lo cut of 700hz and a hi cut of 2300hz as shown below.

On the receive side I used a memory channel for 40M DIGL at 7.177 Mhz with a RX Filter Low of -2300hz and an RX Filter High of -700hz. Using this on the receive side cuts down on a lot of background noise.

I'm currently playing around with settings to better understand what works as I am new to FreeDV.

I am not sure this is good practice, but it works.

Other thoughts??

Tom W4IEE

AA0KM

Using the waveform on a raspberry pi for flex usage it cuts TX filter to 750 to 2250 automatically on the FlexRadio.

RX filter on most radios just cut the RX filter low as you need to and it may or may not help.

Current wave form transmits 1.125-kHz bandwidth soon to go down to 860-hz on the V2 RADE.

TX Frequency width and RX audio width/height :)- not the same thing.

750hz to 2250khz TX Microphone

Also the FreeDV narrows the width anyway.

https://github.com/drowe67/freedv-gui/blob/master/USER_MANUAL.md

Flat audio in also no EQ.