Transmit alignment 1 tone vs 2 tones???

[Lkaskel]

Good Day Everyone,
I was just looking through the TX alignment proceedure for a Robyn 520D and I noticed that it called for a 1000Hz tone. That was different than the proceedure for the President Washington and Cobra 138 which called for a 500Hz and 2400Hz. All 3 have the 858 chipset. Which is the best pratice and why?

Thanks as always!!!!

 

[brandon7861]

Single tones are most commonly used for adjusting things like AM modulation depth. Two tones are used to check the linearity of an SSB transmitter.


Mikes radio repair has a good video on it too, and he shows what happens when you mess up the final or driver bias. This is where a lot of splatter comes from.

 

[AxlMyk]

I have an audio app on my phone that can produce multi-tone output. I was wondering the same thing as you brought up.
I found that a 3 tone signal, using the radios' microphone, produced the steadiest and highest output level of the radio. It uses 1.5khz, 1khz, and 500hz. RF output is significantly higher than a single 1khz tone.

 

[brandon7861]

The tones cannot be harmonically related to each other.

 

[AxlMyk]

The tones cannot be harmonically related to each other.

I have another one at 1900, 1300, and 900, but you can make a generator with 16 tones if you wanted. I use it to adjust the radio output to get the amp where I want it. The android app I use is Tone Generator Pro written by Wedoandroidapps .

 

[brandon7861]

You really only need 2 tones. There is no benefit to adding more.