[App_rpt-users] tone sent in usbradio setting

[Pierre Martel]

Hi I am trying to find what is the frequency of the tone sent when we use
the command radio tune txvoice??

I am asking cause if it would be 1247 hz we could use the bessel null
methode to adjust our tx to 3hz with just a simple rtl-sdr and sdr#

the theory behind this is a bit complcated but at a certain frequency and
level the carrier is completly or almost completly off.

this can easily be seen on a spectrum analyzer. but our sdr# are like
spectrum analyzer.

so if we would want a 3khz deviation we need to send a 1247 hz signal and
adjust the levels till the main carrier disapear on the spectrum analyzer.

the maths are this 3000/2.405=1247

you can see the theory at use here:

https://www.youtube.com/watch?v=8IBOYoIV5m8

So if there is a way to decide the tone we want we could use that methode
to adjust or repeater deviation ( for the voice part at least)

now if we wanted to adjust the deviation for the ctcss, this is another
story. but could it be calculated by the voice level setting if sent on the
same output?

thanks for listening to my crazy idea ;-)

By the way you can set a radio with a sound card attached to it a known
level and use that as the signal to adjust the rxvoice level also. since we
can set that with simple audio generating software available free online
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