Ramsey Electronics QAMP20, Assembly And Instruction Manual

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QAMP20 • 7
In all the following instruction steps, our word "INSTALL" means to do the
following:
•
Insert the part, oriented correctly, into its correct holes in the PC board.
•
If helpful, gently bend the part’s wire leads or tabs to hold it in place, with the
body of the part snugly against the top side (component side) of the PC
board.
•
Solder all wires or pins of the part, whether the 2 wires of a resistor or the 3
or 4 wires of a transistor.
•
Trim all excess wires extending beyond each solder connection, taking care
that wire trimmings do not become lodged in PC board solder connections.
CONSTRUCTION:
Since you may appreciate some "warm-up" soldering practice as well as a
chance to put some "landmarks" on the PC board, we'll first install some
"hardware" components.
ˆ 1. Install S1, PC mount pushbutton switch. Solder all 6 pins securely.
ˆ 2. Install J1and J2, PC mount RCA phono jacks. Solder all 4 pins on each
securely as these connectors will be subjected to some stress when
coax cables are connected to them.
ˆ 3. Install J3, PC mount DC power jack.
ˆ 4. Install relay K1. Notice that it installs only one way.
ˆ 5. Install potentiometer R4. This pot allows adjustment of the bias to the
power transistors.
ˆ 6. Install C9, .01 µf disc capacitor (marked .01 or 103 or 10 nf).
ˆ 7. Install Q5, 221334 PNP transistor, with the flat side oriented toward D2.
ˆ 8. Install R6, 470 ohm resistor (yellow-violet-brown).
ˆ 9. Install R10, 51 ohm resistor (green-brown-black).
ˆ 10. Install R11, 2.2 K ohm resistor (red-red-red).
ˆ 11. Install R12, 10 K ohm resistor (brown-black-orange).
ˆ 12. Install D2 and D3, 1N4148 style signal diodes (glass body with black
band). Pay special attention to the banded ends. The banded end on a
diode is the cathode and must be oriented correctly or the circuit will
not work. Both diode D3 and diode D2 are detectors for sensing applied
RF power.
ˆ 13. Install C10, .1 µf disc capacitor (marked .1 or 104).
ˆ 14. Install R7, 100 K ohm resistor (brown-black-yellow).