Harbach Electronics SS-221 User Manual

SS-221 “SOFT START” INSTALLATION INSTRUCTIONS

PARTS S UPPLIED WIT H THIS KIT:

(1) SS-221 “Soft Start” Circuit B oard Asse mbly
(1) Full-W ave Bridge Rectifier (1A 400 PIV)
(1) #8 Bent Solder Lug
(2) 200V ZNR Transient S uppressors
(1) 390V ZNR Transient Suppressor
(2) 1N4005 Diodes (1A 600 PIV)

To start the installation, read these instructions very carefully. Now unplug the amplifier
and remove any input, output and control cables that may be connected to the back of the
amplifier. Place the amplifier on a book, front panel up, and remove the bottom screws holding th e
feet and case in place. Lift the case up and remove it from the amplifier. Place the amplifier
upside down on the bench with the front panel facing you. Place the SS-221 module in the open
space on the chassis over the capacitor bank with the attached large black leads coming out
toward the back of the chassis. You are now ready to proceed with the installation.

( ) Cut the 2 c able ties on t he power lead w iring that a re nearest the back pan el.

( ) Locate the large black wire coming from the right han d te rm inal of the low er circu it breake r.

Unsolder this w ire and clean the h ole in the terminal of th e breaker.

( ) Cut ½” off of the end of this wire and strip about ¼” of insulation from the end of the wire.

From the component side of the SS-221 circuit board, pass this wire through hole “C” and

solder.

( ) Solder the wire coming from hole “A” in the SS-221 circuit board to the circuit breake r

terminal just vacated, trimming as necessary. This is easiest to do by first tinning the end

of this wire.

( ) In a like manner, remove the large black wire from the right hand terminal of the upper

circuit breaker. Prepare the terminal and wire as previously described.

( ) Pass this wire through hole “D” on th e SS-221 circuit bo ard and so lder.

( ) Solder the wire coming from hole “B” of the SS-221 circuit board to the circuit breaker

terminal just vacated, trimming as necessary. This is easiest to do by first tinning the end

of this wire.

( ) Locate terminal strip “BT”. It has 2 resistors, a 20µF capacitor and a d iode con nected to it.

It is located on the left side of the chassis, slightly forward of middle. Remove the diode.

Remove the red transformer wire connected to the center ground lug. Clean out the ground

lug and the lug that has the “+” term inal of the cap acitor soldered to it.

( ) Find the small bridge rectifier s upplied w ith th e kit. Note that the (+) lea d is slightly longer

than the rest. This is the plus (“+”) lead and is marked on the top of the bridge rectifier.

With the rectifier on the right side of the te rminal strip (wires up), put the (+) thro ugh the

most forward termina l (lug) on the strip (the one with the “+” lead o f the capacitor going to

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it). Put the red lead from the SS-221 module through the same terminal lug, trimming as

necessary. Solder 5 wires at this lug.

( ) Put the (-) lead of the bridge rectifier that is opposite of the (+) lead through the center

(ground) lug of the term inal strip. Put the black lead from the SS-221 module through the

same terminal lug, trimming as necessary. Solder 3 wires at this lug.

( ) Solder the left lead of the bridge rectifier to the terminal lug that has the red wire from the

transform er soldered to it.

( ) Solder the loose red transformer wire (removed earlier) to the remaining lead of the bridge

rectifier.

( ) Position the bridge rectifier so that it is clear of any wiring. It will be held in place by its

leads.

( ) Locate the 8-32 screw just forward and to the left of the line voltage selector strip. This

holds down one corner of the HV tra nsformer. Remove the nut and place the #8 solder lug

(supplied) over the protruding screw. Replace the nut and hand tighten.

( ) Take the 2 ZNR suppressors marked 14K20IU and put one lead of each through the new

solder lug. The other end of the ZNR suppressors goes to the end terminals of the voltage

selec tor terminal strip (N OT to the scre ws holding the strip down).

( ) Position the ZNR suppressors and the ground lug so that the ZNR leads are in the clear.

Solder the 2 leads to the ground lug and trim off any excess. Now fully tighten the 8-32

screw and nut holding the g round lug an d transformer.

( ) The ZNR suppressor marked 14K39IU is connected between the end terminals on the

voltage selector terminal strip (the same strip where the 14K20IU suppressors are

connected). Place the leads from the ZNR suppressors under the terminal screws and

tighten.

( ) Dress the power leads back into the wire bundle and tie using lacing, cord, string or tie-

wraps.

( ) Locate the antenna changeover relay and identify the wires connected to the relay coil.

There should be a red wire on the lug nearest the front panel. Solder the lead from the

banded end (catho de) of one of the sup plied diodes to the re lay coil lug with the red wire

soldered to it. Solder the lead from the unbanded end (anode) of the other diode to the

opposite relay coil lug. Both free diode leads should be extending to the right, toward the

output coax cable.

( ) Bend the two free diode leads so that they touch, but are clear of any other wiring. Solder

these leads tog ether.

( ) Place the SS-221 module in the clear space in front of the input voltage selector terminal

strip, relays down. When a go od location has been found, lift the module and clean the

chassis at this location with alcohol or other similar cleaning fluid.

( ) Place a small dab of silicone adhesive on the top of each relay and place the SS-221

module back onto the chassis. Use a weight of some kind to hold the SS-221 module

down. Let the silicone cure for at least 12 hours (24 hours is better) before reassembling

the case to the amplifier.

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