the Alpha86 has same issue
The new plate choke is from RF Parts
On RF Parts catalog, you may find two labeled RFC3
The Amp used (Abomination) method to short part of the plate choke based on band selection
note at back of the amp at coax in/out connections. Those are sense boards for SWR,drive input, Power out
IF one or more of those functions don't work on your 89, Most likely burned out diode on one or both of those boards
Another view of flapper damaged by arc'ing during operation
found one of the screws holding the flapper was loose
Replacement of Plate choke allows operation without the flapper
left the relay in place and removed two screws holding the flapper
Location of bottom screw holding original plate choke
The screw hole must be drilled out as the new RFC3 uses larger screw
I used a bolt
same size as hy-gain SS bolt on element support - keep several of those SS as spare
A KEY ITEM IN MAKING DECISION TO REPLACE THE PLATE CHOKE, RF PARTS DELIVERS EVEN IN PANDEMIC
showing wire connection at bottom of RFC before soldering
this connection will provide little fustration, hook the wire on, then solder
Installed new plate choke
One must be creative to attach lugs to top of tube in an Alpha
Opps when RF was applied, arc. Bend the DC blocking cap up and away from tuning Capacitor
Heathkit dummy load, 1500+ out on 40 meters, good test
Heathkit dummy load, 1500+ out on 15 meters, good test
Opps when RF was applied, arc. Bend the DC blocking cap up and away from tuning Capacitor
Heathkit dummy load, 1500+ out on 40 meters, good test
Heathkit dummy load, 1500+ out on 15 meters, good test
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Last updated 28 Jan 2021