APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL prodlit@apexmicrotech.com

1

INTRODUCTION

This kit provides a solid mechanical platform with good shield-

ing and grounding to breadboard eight pin TO-3 packages or the

MO-127 package with 0.060" pins. This kit is not intended as

an alternate for kits dedicated to specific amplifiers. See www.

apexmicrotech.com for availability of dedicated kits.

Construction will involve surface mounting and 3D techniques.

Holes are provided to mount standard banana and BNC connec-

tors for I/O. See the Apex Accessories Information data sheet

for a selection of flat-back heatsinks and thermal washers for

these packages.

Note that HS11 is compatible with EK09 and all three sockets

can be used if desired. If the EK09 is to be used as an MO-127

platform only, HS18 rated at 1° C/W is a cost effective alterna-

tive to HS11 if internal power dissipation permits. Lower cost

alternatives for two package TO-3 applications are HS02, HS01,

and HS09. For single package TO-3 applications the HS13 is

also suitable. The six chip capacitors provided can be used as

the critical first step in power supply bypass for dual supplies

for all three sockets. These capacitors are rated at 200V.

PARTS LIST

Part #

Description

Quantity

PB99-P2

top

1

PB99- P6

side

2

PB99-P7

side

2

MS02

cage jacks for one TO-3 socket

2

MS04

cage jacks for one MO-127 socket

1

OX7R105KWN 1µF Cap 1825B105K201N,Novacap

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BEFORE YOU GET STARTED

• Attempt to visualize the finished circuit mechanically and in

terms of where the high currents flow.

• Use proper ESD precautions.

• Verify heatsink is adequate

• Use thermal grease or Apex thermal washer.

• Do not make or break any connection on a hot circuit.

• Start with lowest rated voltages.

• Checking for oscillations with an oscilloscope is a must.

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ASSEMBLY

Let us define the side of the top board with solder pads for each

pin (roughly triangular on the TO-3 sockets) as the component

side, where all the support components will determine circuit

function and will be inside the finished box. The other side of

this board is hereby dubbed the amplifier side.

Insert cage jacks from the amplifier side and solder. Consider

one of these techniques: 1) Place cage jacks in holes, cover

with one of the 6" copper sides, flip over and solder, or 2) place

cage jacks on pins of the amplifier, insert and solder. If done

carefully, technique 2 can be used for the MO-127 package

with 0.040" leads.

Starting with one short and one long side, locate a vertical

square corner in your work area (a large heatsink standing

on end works fine) and solder the two together. Repeat for

the other two sides, and finally solder the two pairs together.

With the component side up , place rectangle of sides on top

and tack two opposite corners. When satisfied with alignment,

solder the box together then add connectors and components

as desired.

Note that copper on the inside and on the top of the box will

all be tied to ground. Copper on the four outer sides of the box

will be floating unless you tie them down.

Soldering a stranded #10 to #16 ground wire from the immedi-

ate area of the socket(s) to the ground connector of the power

supply(ies) is good construction practice. If the circuit is not a

bridge, run this same size wire from the socket area to the out-

put return connector. This will avoid high currents in the ground

plane which may destroy signal integrity or even an amplifier.

This is a good time to think about star grounding where each

ground connection has a dedicated path to the center of the

star such that currents in any path are not capable of inducing

voltage in any other path.

Note that the layout makes it easy to locate the star center

nearly coincident with the socket center.

Auxiliary circuits may be mounted inside the box in 3-D fash-

ion supported on ground connections or on daughter boards

as convenient. Other style connectors, switches or indicators

can easily be added by simply drilling the appropriate holes

and mounting them.