R.V.R. Elettronica 4CX7500, Technical Manual

Page: 47 / 82

Date: 25/07/03 R.V.R. Elettronica S.r.l. (BO) VJ10000-TE - R.F. Tube Amplifier
47
Before to proceed, check the test resistors values in according to the amplifier type that is
used (in this case the type is VJ10000-TE that uses 4CX7500 tube, see as reference
TABLE D
and
FIG. 37
).
Since, the protections intervention on the equipment is set at 3.9 V, is necessary that at
maximum voltage or current value of the tube corresponds to 3.9 V, to allow the protections
intervention.
Example:
A value for VJ10000-TE, tree-phases version, with 4CX7500 tube. IA max set to 2.5 A
corresponds to 3.9 V on the TP6 test point output. In this way if the current exceeds 2.5 A
value the protections intervens. In the manual there is a table with all input and output
voltage of the card.
IA = 2.5 A Ig1 = -50 mA
VF = 7 VAC Ig2 = 100 mA
ROS o RFL = 1000 W If = 110 A
4.3 MEASURES CARD ADJUSTING OPERATIONS
Adjusting procedure of the card at first switch on of the equipment in case of card
replacement.
The first operation that must be executed is that to calibrate the card reference voltage (3.9
V), using P15 trimmer.
To measure it using a multimeter connect the negative to ground and the positive to TP9 test
point.