Specifications

C1-C6 = .01 µF ceramic disc capacitor (Radio Shack #272-131 or #272-1065)
C7 = .001 µF ceramic disc capacitor (Radio Shack #272-126)
D1-D6 = 1N914 type fast switching diode (1N4148, ECG519, Radio Shack #276-1122)
L1-L7 = 470 µH RF choke (Mouser or Circuit Specialists #43LS474)
R1 = 1KΩ, ¼-watt resistor (brown-black-red, Radio Shack #271-1321)
CT1-CT6 = 9-50 pF plastic or ceramic trimmer capacitor, micro-miniature 5mm size.
(Mouser/Circuit Specialists #ME242-8050 or #24AA024)
NOTE: Any fixed ceramic capacitor of about 10-68 pF can be also used at CT1-CT6 to trim exact crystal
frequency. You can even use a bare jumper wire if no trimming is needed. But you must install
something in these holes to complete the RF continuity to ground; otherwise the circuit won’t oscillate!
Miscellaneous:
1 each, EXPANDER 240 printed circuit board.
Crystals and switch per your requirements. (See text.)
Most parts are available from Radio Shack except for the trimmers and RF chokes. See Page 3 for addresses of
other suppliers.
A complete kit is available for $28 including shipping from:
CBC INTERNATIONAL, P.O. BOX 30655, TUCSON AZ 85751 U.S.A.
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EXPANDER 240 PAGE 8