T.E.M. A07B500S, Manual

Page: 45 / 131

A07B500S manual
Pag. 45
The SMB at 90° angle which drives the RF input signal to the power module is to be disabled and
RT4 and RT2 are adjusted, so that the value 0 is displayed on the LCD at the correspondence of the
forward and reflected power measurement.
At this moment the input power is to be connected, at 98MHz frequency with a 500W power will be
set, it must be connected a thermal wattmeter at the antenna output and RT3 is set to read on the
display, at the correspondence of the direct power, the 500W value, read also on the thermal
wattmeter.
Then the thermal wattmeter is to be disconnected and replaced with a directional Wattmeter
connected without 50
?
charge as to have all the reflected power. A 50W reflected power is to be
set and RT2 adjusted to have the same reading on the measurement instrument.
6.4 MBP
BOARD - MOTHER BOARD
On the mother board it’s possible to perform the modulation width setting, of the stereophonic
coded signal levels, the automatic check gain regulation threshold, and the phase compensation and
the multiplex signal width.
The mother board receives on three connectors the VCO oscillator module (SINTD), the
stereophonic coded module and the automatic check gain module.
Adjust the trimmer RT4 of the MBA board as to have +8Vdc at R7 ends.
Inject a +6dBm signal into the rear MPX input, after the same level in the settings window has been
selected, then adjust the RT5 trimmer to read 75KHz on the measurement main page at the
modulation correspondence, by TX in MONO.