Ramsey Electronics FX Series Manual page 68

B13. Use two 8" lengths of hookup wire (or 8" of 2 conductor wire) to
prepare the Speaker Cable. Neatly strip and tin all 4 ends as in Step B11.
B14. Solder both wires of one end of this speaker cable to the two marked
points near C37.
B15. The other two ends of the speaker cable may be connected in any of
the following ways:
Standard:
To J2, the 3.5 mm miniature speaker jack. The
3.5mm miniature jack is the larger of the two
miniature jacks supplied with your kit.
Optional:
To a test speaker, temporarily or to a speaker
intended for regular use inside or along with your FX-
Transceiver.
B16. Solder the speaker cable to your choice of speaker. Give attention to
the polarity marks on most bare speakers as well as enclosed units. The
wire from the point marked SPKR should be connected to the speaker
terminal marked (+).
Stage B: AUDIO AMPLIFIER TEST:
1. Reconnect 12 volts DC as done for testing the power input circuit in
stage A. (We assume speaker hookup per B15.)
2. Turn on power switch S1. All you should hear is one gentle "pop" in the
speaker. There should be no hiss or whistle. Touch the center terminal of
the volume control and you should hear a moderate AC hum. If you wish,
connect a test oscillator or line-level audio source to the input line to the
control. You should hear a generous level of good quality audio sound.
3. Disconnect DC Power before proceeding with assembly.
4. The volume control, speaker and other wired connections are installed
quite early in the assembly sequence so that tests can be performed
periodically during assembly. The disadvantage to this approach is that
there is considerable wear and strain on the various wire connections as
the PC board is repeatedly flipped back and forth during assembly. This is
a serious consideration because most radio malfunctions are due to
broken wires and not component failure. For this reason, such wiring is
usually done at the final stage of assembly. To minimize damage to the
controls and wiring, use a wire ty-rap, plastic bag tie or a scrap piece of
hook-up wire to hold down this group of wires temporarily. A convenient
point is to loop your tie through one of the PC board mounting holes near
U10.
SPEAKER JACK
GND
OU