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AM-10HD / Aug 2008
A M - 1 0 H D G U I
4. Turn on the AM‑10HD Test Oscillator “Tilt Test” by clicking its checkbox.
5. Using an oscilloscope connected to a low level RF sample of the transmitter output
observe the resulting RF waveform.
6. If the transmitter has adequate LF response the waveform will appear similar to
figure C.
7. If it has less than adequate response the waveform will appear similar to that in
Figure A.
8. Depending on the magnitude of LF correction required the waveform’s appearance
may even appear to be somewhat between Figures A and C.
9. If the response of the transmitter does not resemble the perfect low frequency
response represented by Figure C, alternately adjust the Tilt Corrector’s “F” (Fre‑
quency), “Q” (Bandwidth), and “L” (Level) controls in order to achieve the flattest
top and bottom of the waveform.
It is entirely possible to overcorrect for tilt. If the transmitter response starts looking
like Figure B you have gone too far.
The ideal case is to have the waveform look exactly like Figure C, but sometimes
perfect correction is not possible, particularly on older plate modulated transmitters with
inter‑stage coupling transformers* (see below).
* For older transmitters that cannot be adequately tilt corrected it is not recommended
to operate them with gross amounts of final clipping in the processor, large amounts
of bass equalization, and positive modulation beyond 100%. Doing so (or attempting
to do so) can overstress components in the transmitter leading to overheating and
damage.
