[Kenwood] two tone test question

[Bill Smith]

----- Original Message -----
From: rb
To: kenwood@mailman.qth.net
Sent: Wednesday, December 17, 2003 3:41 PM
Subject: [Kenwood] two tone test question


When looking at a two tone test trapezoid from the final amp.

1.  I assume my xcvr needs to be on CW mode, while the amp should be in SSB
mode.  Correct?

No, you must modulate the transmitter, in this case, the exciter with two
tones.  SSB or AM.   CW is only a carrier and will produce only a vertical
line.

2.  What effect does increase or decrease of xcvr audio level have on the
trapezoid?  I assume it distorts it in some way if over or under driven.
What I'm getting at here is what do I look for to tell me if the audio gain
is optimal?

The pattern should resemble a filled-in triangle.  Rounded or misshaped
corners, or concave/convex edges of the triangle all point to non-linearity
(distortion).

3.  What effect does increase or decrease in rf drive level have on the
trapezoid?  Within the bounds of linearity, I assume it only makes the
pattern bigger or smaller proportionally.  Is this correct?

Think so.  AM undermodulation might show a line (carrier) with a triangle of
size dependent upon modulation.

 I further
assume that if I get into non-linear operation, it distorts the pattern.  Is
this correct?

Yes, that is the point of this test.  It is easy to recognize distortion.

I've never done one of these and am just trying to anticipate what I'll be
encountering.

I haven't either.  :-0)  But this test is highly recommended by others more
skilled than I.

- - -

73 de Bill, AB6MT