Henry RF AMPLIFIER
RF Deck Removal / Pedestal Type
*** DANGER ***
RF Amplifiers Have Lethal HIGH VOLTAGE Inside
Internal RF Deck Removal Procedure:
The following procedure can be used to remove thel RF deck chassis from
pedestal cabinets like shown in the picture. For other Henry RF amplifier
pedestal types, this procedure should be very similar, however some
screw locations and band linkage maybe different.
Henry 2K-4, 3KA and 2K-Classis type RF amplifiers
1) Remove AC power, transceiver and antenna connections.
2) Remove the bottom rear pedestal power supply cover (6 screws total).
There are no nuts. This is the rear cover with the air filter.
3) Remove the top ventilated cabinet outer cover (4 screws total). There
are no nuts.
4) Remove the inside RF deck shield (9 screws total, 6 inside and 3
from outside rear top) There are no free nuts.
5) Remove three knobs from the front panel (LOAD, TUNE and BAND) Bristol
6) Looking down inside the top of the pedestal cabinet, in-between the
internal RF deck chassis and the front panel, you will see a "lip"
on the bottom of the RF deck with two or three nuts holding the RF deck
to the top pedestal cabinet. The screws for these nuts can be accessed
from either the outside bottom of the top pedestal cabinet, under the
front panel, from the top of inside of the bottom power supply section.
Remove the screws and nuts.
6) From inside the power supply section of the pedestal cabinet, about
1/2 inch in from the rear in the top you will see three screw which
screw into the top RF deck chassis, Remove these three screws. There
are no nuts.
7) From inside the power supply section of the pedestal cabinet, on
the bottom of the top RF deck chassis, unscrew the HV cable connector,
then unplug the 8 pin octal plug and the square filament plug from the
8) Slide the internal RF deck chassis out of the top of the pedestal
Henry 2K type RF amplifiers
1) Remove AC power
2) Remove top RF deck cover
3) Remove 3-400 tubes and chimes
4) Remove chassis power supply bottom front cover
5) From inside bottom power supply, disconnect HV cable and 8 pin octal
plug from top RF deck
6) From inside bottom power supply, disconnect fan & AC cables attached
to two feed through capacitors going to the top RF deck
7) From inside the RF deck, along the outer edge, remove nine (9) sheet-metal
8) Remove three (3) screws on chassis rear, next to RF coax connectors
9) Lift the RF deck off the power supply pedestal
All the above steps may read like lots of complex work, however once
you have performed this, you will see its quite simple and should only
take about a 5 minutes to complete.
With the RF deck on the workbench, remove the chimneys, tubes and bottom
RF shield with all the counter-sunk Phillip screws.
I recommend at this time to use compressed air and blow all the dirt
and crud out of the RF deck before going any further.
Assemble the amplifier in reverse order as described above.
73s Thomas NE7X