harbach-electronics sk-201 Benutzerhandbuch

1

(1) SK-201 “S oft K ey” Circuit Board  Assembly
(1) Nylon Threaded Spacer
(2) 6-32 x ¼” Screws
(1) 2-Lug  Terminal Strip
(1) #6 Lock W asher

To start the  installation, read these instructions very carefully.  Unplug the amplifier and

remove any input, output and c ontrol ca bles that may be co nnec ted to the back of the amplifier.
Remove the chassis from the case and remove the perforated sheet metal RF shield from the top
of the chassis.  Remove the tubes and put them in a safe place.  You are now ready to proceed
with the installation.

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Turn  the amplifier over so that the rear is toward you.  Locate a point that is 8” from  the
right edge of the chas sis and 4 ½” from  the rear of the chassis.  Mark this point.

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Very carefully drill a hole that will clear a 6-32 screw at the point you just marked (#27 drill).
Do not use too much pressure because you want the drill to stop after just penetrating the
chassis.  Clean up any burrs from the hole.

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Rotate the chassis so that it is o n its side w ith the transform er do wn  (it is m ore s table that
way).  Push (1) 6-32 screws through the hole from the tube side of the chassis.  Put on a
lock washer and attach the nylon spacer onto the screw (on the underside of the chassis
and tighten.

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Inside the tube compartment, locate the screw that fastens the RF shield to the chassis and
secures terminal strip “Q” to the underside of the chassis.  Terminal strip “Q” is a 5-lug
strip mounted at a  right angle to the re ar of the chassis.  Loosen this screw and remove the
nut while keeping the screw through the chassis.

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Place the hold down lug of the supplied 2-lug term inal strip over the end  of the 6-32 screw
(the one you just rem oved the nut from).  It may require some a djustment of the wiring
harness to m ake roo m for the strip.  T he strip sho uld be oriented app roximately parallel w ith
the existing terminal strip “Q”.

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Reins tall the 6-32 nu t onto the screw  and tighten.  Now  turn the am plifier over (bottom up).

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Locate  the 33

Ω

  1W  resis tor going from the antenna relay jack on the rear panel to a solder

lug at the end of the primary voltage selection strip.  Unsolder the  res istor from the jack and
move the end so that it goes through the insulated terminal on the 2-lug terminal strip you
just installed.  DO NOT solder yet.  Leave the 0.02

µ

F disc capacitor connected to the

antenna re lay jack.

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Install the SK-201 circuit board on the nylon spa cer w ith a 6-3 2 x ¼” screw.  Orient the
circuit board  with the long side parallel with the rear of the chassis and the TO-220
transistor away from the rear of the chassis.