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Old December 12th 04, 06:10 PM
 
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Incidentally for anyone who already owns a Howes AA2 amplifier I have
some (incomplete) information here (if you are trying to connect it all
up!)

Frequency range=150khz - 30 Mhz
Power supply = 12-14V DC

On the circuit board:

Link "LK3" is for coxial powering. Do not link this if you are going to
use direct powering (i.e. on pins "E" and "+VE").

Link "LK2" increases the gain of the module; a switch can be used but
the wires must be no more than 1" (25mm) or so.

Link "LK1" should be made if a diapole ariel is in use rather than a
single wire.

Pins "A" and "B" are the pins to which to connect a diapole ariel. If
you are using a single-wire ariel, connect to pin "W". Each part of the
diapole ariel (the 2 wires connected to "A" and "B") should be about 3
to 4 ft long. A telescopic ariel could be connected to pin "W" if you
are using a single wire ariel.

Pin "E" is to power the unit, earth (0V); Pin "+VE" is the positive
power supply pin; the unit needs 12 to 14V.

Pins "OP" (output) and "E" (earth) is for a coxial cable to supply the
unit's output for connecting to a radio.

Coax powering the AA2 module can be done too. The power is fed up the
same coax is used for the signals coming out of the unit (the "OP" and
"E" pins). This requires a capacitor to do this (Disc capacitor "103").


List of components:

R1 (1M5)
R2 (82k)
R3 (330R)
R4 (1k2)
R5 (270R)
R6 (270R)
R7 (2k2)
R8 (10R)
R9 (47R)
L3 (inductor, two red bands, brown band, silver band, green body)
C1 (1nf, Marked 102)
C2,C3,C4,C5,C6,C7 (0.1uF, marked 103)
C9 (.1uF marked 104)
C8* (100uF) - electrolytic make sure it is fitted the right way round!
TR1 - BF245 (FET). The type number is marked on the transistor.
TR2 - RF Power transistor 2N4427.
L1 - Inductor, two sets of cables - 3 turns.
L2 - 40 turns of enammelled wire

SP