SimpleUSB vs USBRadio TX Audio Limiting?

App_rpt-users
1

Is there any TX Audio limiting function on SimpleUSB for driving discriminator? If not, have other people had any problems driving the discriminator with SimpleUSB?

I’ve had to revert to USBradio on some Kenwood mobiles because i’m getting 7+KHz deviation on hot users audio even when alligned for the 1KHz 3KHz deviation test tone.

2

Could you clarify? Discriminator audio is not “driven” as it is a source

3

Taking a few guesses…

if you are using discriminator audio…
deemphasis = yes
txboost = 0

re-calibrate

4

Sorry, I was wrong in my terminology.

I am talking about the transmit audio path, using FLAT audio ( no pre-emphasis or limiting on the radio)

With the usbradio channel driver, there is a limiting function that limits the transmit deviation of the radio to prevent it from over-modulating.

The simpleusb driver does not seem to have any limiting functions. Am I correct? That is all I wanted to ask.

5

I think that’s right. The sample config files for simpleUSB do not show any limit parameter. Some repeaters have a limiter built into them. But, if you are using a really simple mobile radio as a transmitter for your homebrew repeater, then anything can happen.