testing modultion no meter

[jessejamesdallas]

Get on channel 19 and ask for a "Radio Check"...When someone comes back to you...Ask them if they can hear you...If they say "YES, Loud and Proud, Tree-Top Tall", then you know you have decent modulation!

If they say "Wha'ed, he say?" Then you know you need to turn up the Mic gain...

 

[Robb]

The scope patterns . . .

Left: 110% Positive 85% AM asymeteric
Center: AM over-modulated (high level)
Right: AM over-modulated (low-Level)

http://www.nu9n.com/am.html#2

 

[RatsoW8]

Even then you could be off by as much as 10% or more depending on the accuracy of the power meter. You would also be hard pressed to make a good measurement using regular voice and not a steady tone.

Except for the Captain's the comments the replies in this thread are frightening. If you have no meter or scope to measure modulation there is no way to set it and ensure no distortion. Period.

 

[WR0220]

Put your radio in SSB mode with the mic gain turned all the way down. Key up and talk normal into the mic as you slowly increase the mic gain. Keep an eye on your meter, and once you get to where you no longer see an increase in power, stop, then back the mic gain off a hair.

See comment one post above. You cannot accurately set modulation levels by watching an RF power meter and adjusting audio for maximum output especially using a complex waveform such as speech.

Except for the Captain's the comments the replies in this thread are frightening. If you have no meter or scope to measure modulation there is no way to set it and ensure no distortion. Period.

Thanks for the clarification guys. I didn't realize that bad information could come from so many 'reputable' sources. The above method was mentioned a couple years back in QST magazine, recommended by many of the 'in the know' members of QRZ and also recommended by a few of the locals at a club meeting. I have used this method and everyone has always told me my audio is crystal clear, articulate and very easy to copy. Of course, if the AMC is disabled or a swing kit added then all bets are off...