JRC JMA-7710-6 Instruction Manual page 234

8.4
[Replacement of Magnetron V201 (25kW : NKE-1056)]
Replace the magnetron as follows:
(1) Loosen the four A screws from the cover on the left side (when the scanner unit is viewed from the
cable ground) to remove the cover (see Fig. 8.5).
(2) Remove the three modulator cover B screws and loosen the seven C screws to remove the cover (see
Fig. 8.6).
(3) Make sure that the modulating high voltage circuit has been discharged before removing the magnetron
socket (see Fig. 8.7).
(4) Remove the six D screws fixing the magnetron to remove the magnetron (see Fig. 8.7).
(5) For remounting the magnetron, follow the opposite procedure.
In this case, properly connect the lead wires.
Handling of magnetron which had been stored for a long time
Since the magnetron which had been stored for a long time may cause spark and become unstable after you
start using it, age it as follows:
(1) Make the cathode pre-heating time longer than usual (for 20 to 30 minutes in the standby mode).
(2) Start the operation from the short pulse range and gradually change it to the long pulse range. If the
operation becomes unstable during the process, return it to the standby mode immediately. Leave it as
it is for 5 to 10 minutes and operate it again.
(3) Set the range to 24nm or more, and put the radar into the transmission mode for about 15 minutes and
adjust the tuning.
(4) Adjust RV1 in the receiver so that the [TUNE] bar indicator of the display unit reaches 10 without
saturation.
Fig. 8.5 Internal View of 25kW Scanner Unit NKE-1056
A
A
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