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Bendix 55P3 RestorationBendix 55P3 Restoration
Paul Pinyot.Paul Pinyot.
KB3LZPKB3LZP
You have to clean the shop some times! I
choose between units.
Typical AA5. A Bendix 55P3.
Model, manufacturer and tube location on sticker.
Sometimes the model number is inside or only
a chassis number.
Screws in a pill bottle
Tape or Gum Band a hard cardboard cover
on the speaker to protect the cone.
Label Antenna wires
Ohm out antenna coil. It is part of a tuned circuit.
Check all coils and transformers for bad
unopbtainium
IF continuity primary and secondary. Use schematic to
find pins not in series with capacitors integral to the IF
can.
Touch a 9 volt battery on the primary of the audio output
transformer. If the speaker pops all is well. The primary, secondary
and speaker voice coil. This does not work with eletrodynamic
speakers.
Record you results. Green for good, Red for open
This is an emissions tube tester. Quicker than a Mutual conductance. The tube
must work in the unit.
SHORT! Do not power up
in chassis!
This tuning shaft oxidized concaved area would catch the dial cord. Remove and sand smooth 220 grit emery
cloth
A dab of hi temp lithium grease give control a
smooth feel.
Flush the tuning gang’s ball bearings with contact
cleaner or denatured alcohol and replace the
grease.
Don’t get any grease on the
capacitive fins!
Mr. Jingles left his mark here !
@#%
Two section 40uf electrolytic capacitor.
Wax/paper capacitors
Two caps of 40 uf 160 volts and one 200 uf at 50 volts
These caps do NOT connect to chassis ground! Two caps are parallel to make up 40uf. The
other is a singe 47uf 160v standard value.
4 post terminal strip that is screwed to the chassis. Do NOT use the 4th post as it is chassis ground and not B- or
circuit ground.
New electrolytic cap array screwed to chassis using original capacitor
lead wires.
This is an UL rated safety capacitor
used for RF bypass.
This cap and a parallel 220k resistor are
connected from circuit ground B- to chassis
ground and makes this a HOT chassis.
This cap will be replaced using hooks. Clip the cap close to the body leaving all of the lead wire.
Form a hook with the needle nose pliers to receive
the complimentary
hook of the replacement cap.
The new capacitor is the same or slightly
larger in capacitance and is 630 volt rated.
These wax/paper caps will only see up to 120
volts. 630 volts are used simply because of
bulk purchasing discounts and
minimizing inventory.
Place new cap lead wires in hooks, form into
reverse hooks clip excess and crimp.
Crimped
Crimp
Solder the connection.
Alligator jumper used to mark original capacitor’s
lead wires.
This comes in real handy for interruptions like the phone
or lunch.
Spaghetti insulation is added. The
replacement is smaller than the original.
These lead wires will be curled on a stiff wire and slipped over the
original lead wire in the chassis.
Home made tool using an Exacto knife handle and a cut off
safety pin.
Roll lead around the pin.
Ends curled and trimmed. Slip these over the original lead wires
and solder.
When heated the coil will often slip under the original
spaghetti insulation. The spaghetti may close up over the coiled and solder splice.
To maintain a vintage appearance restuff the
original capacitor.
This technique is used for a “museum” level restoration. An example is the $21,000,
16 tube Zenith 16-A-63 Stratosphere.
The new cap fits right into the original cardboard.
Use paper slivers to fill the space. Seal with wax or
Hot Melt glue.
Seal the ends with Hot Melt glue or wax,
fresh or original.
You can melt down all the cut out caps,
that you have in your big jar, to
maintain vintage wax.
This radio did not have its capacitor re-stuffed. This is only how you would do it.
Shined up the cabinet with a power buffing wheel, rouge, Novis Polish and Glayzit.