Ametek Dycor Dymaxion Mass Spectrometer, User Manual

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7-6 | Dycor Dymaxion Mass Spectrometer
RF Card
Removing the RF Card
The RF card is located directly behind the rear heat sink and separated from it
by the conductor guide. See Figure 7-3.
1.
There are eight screws holding the RF assembly in the unit casing.
Remove the (2) top 1/4” and (2) bottom 1/4” screws.
2. Remove the (2) 3/16” screws from each side.
3. Grab hold of the rear heat sink and pull hard to remove the assembly
from the casing.
4. You now have the complete RF assembly in your hand. Refer to Fig-
ure 7-3.
5. Remove the Amp cover by removing the two 1/4” self-tapping sheet
metal screws. The Amp card is underneath.
6. Remove the (4) 1/4” screws holding the Amp Card to the Amp card
shield.
7. Using the 1/4” nut driver remove the (4) 3/8” standoffs from the Amp
card shield. You can now see the RF card.
8. Using the 1/4” nut driver, remove the (4) 5/8” standoffs holding the RF
card to the connector guide.
9. Remove the 1/2” screw on the top right of the RF card. This holds the
card to the aluminum oxide insulator on the rear of the heat sink.
It is very important to remember to replace this screw and insulator when
reassembling the unit after replacing the board. The insulator is coated with
thermally conductive joint compound. If it is not replaced, the unit will not
work.
10. Separate the RF card from the conductor guide.
Replacing the RF Card
1. Using the 1/4” nut driver, loosely attach the conductor guide to the RF
card using the 5/8” standoffs.
2. Plug the analyzer head onto the loosely assembled guide conductor
and RF card. Tighten the standoffs using the 1/4” nut driver.
Failure to secure the assembly to the analyzer head at this point can
result in failure of the unit through cracking of the feedthrough. If the
feedthrough is cracked, a leak will develop.
3. Screw in the 1/2” screw in the upper right corner of the RF card to
connect to the aluminum oxide insulator.
4. Using the 1/4” nut driver, attach the Amp card shield to the RF card
using the 3/8” standoffs.
5. Attach the Amp Card to the amp card shield using the (4) 1/4” screws.
6. Attach the amp card cover to the Amp card using the (2) 1/4” self-
tapping sheet metal screws.
7. Insert the RF assembly into the unit casing and secure using the (4)
1/4” screws for the top and bottom of the unit and the (4) 3/16”screws
for the sides.
It is very important to remember
to retain the conductor guide as
it is not part of the replacement
board.
Failure to install this screw and
aluminum oxide insulator will
cause the unit not to operate.