Ramsey Electronics FZ-146 Specifications download pdf (Page 79)

FX-146 • 79

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 to loop your tie through is one of the PC board mounting holes

near U10.

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Ramsey Electronics FZ-146 Specifications Page 79