Communication-concepts EB27A Construction Hints Manual do Utilizador descarregar pdf

CONSTRUCTION HINTS FOR THE EB27A

These construction hints for the EB27A are only to supplement the Engineering Bulletin

and are not meant to be used as a construction manual.

HEATSINK PREPARATION

A heatsink of sufficient size to dissipate over 300 watts of power should be used. The

heatsink should be marked, drilled, and tapped before construction begins on the PC

board. Using the bare PC board as a pattern, lay the PC board on the heatsink in the

desired position and mark the four mounting holes and the mounting hole for D1. Drill

and tap the four mounting holes and the hole for D1 for 4-40 screws. Then bolt the bare

PC board flush on the heatsink and place the RF transistors through the PC board so

they rest on the heat sink. Mark the mounting holes for the RF transistors. Remove the

PC board from the heatsink and drill and tap the mounting holes for the RF transistors

(4-40 screws). The heatsink can also be fitted with connectors, cover, etc. at this time if

so desired.

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CONSTRUCTION HINTS FOR THE EB27A These construction hints for the EB27A are only to supplement the Engineering Bulletin and are not meant to be use

BROADBAND TRANSFORMERS Just a quick word about the broadband transformers. The low impedance winding of the input (T1) and output (T3) transformers

Figure 2 Solder the wire leads from the output of T3 to the PC board. Clip the excess leads close to the PC board. The input transformer

Install all of the ½ watt carbon resistors in their proper locations (refer to the placement layout in the Application Note and solder in place. Cl

Figure 4 Install the current measurement loops on the output end of the PC board. These are the two “U” shaped #18 wires with three (3) ferrite b

Cut the extra short piece of wire (L5) to 1 ¾ inch and scrape the insulation 3/8 inch back from each end. Install this wire through T2 and into the

This completes the assembly of the amplifier PC board. The unit may now be tested. TESTING 1. Connect a power supply of suitable current output

Band Fcutoff (MHz) L1, L3 (uH) L2 (uH) C1, C2 (pF) 160 2.1 8.1 (23T on T-106-2) 11.4 (28T on T-106-2) 1653 80 4.1 4.1 (16T on T-106-2) 5.8 (2

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Communication-concepts EB27A Construction Hints Manual do Utilizador