Ramsey Electronics AM1 Assembly And Instruction Manual page 10

Am broadcast transmitter
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11. Install Q5, a 2N3904 transistor. Be sure to orient it correctly! See the
parts diagram for correct orientation.
12. Install C7, .01 µF disc capacitor [marked .01 or 103 or 10nF].
13. Install R9, 270 ohm [red-violet-brown].
14. Install C15, 220 µF electrolytic capacitor. Electrolytic capacitors are
polarized with a (+) and a (-) lead and must be installed in the correct
orientation. Ordinarily, only the negative side is marked on the capacitor
body with a dark band and the (-) sign clearly shown, while PC boards
will usually show the (+) hole location. Use care to ensure proper
polarity.
Whew ! Now that wasn't so bad was it? You have just completed most of the
oscillator. Notice that we have excluded a few capacitors, C9, 10, and 16.
We will install these later while testing the unit. Take a moment now to
recheck your work for clean, shiny solder connections. Resolder any
connections that are less than perfect.
We'll get back to building now, starting at the audio input and working
through the audio circuitry.
15. Install trimmer potentiometer R12. Solder all three leads.
16. Install C2, 10 µF electrolytic capacitor. Be sure to orient the part
correctly. See the parts placement diagram for correct orientation.
17. Install R5, 1K ohm [brown-black-red].
18. Install C12, .01 µF disc capacitor. This capacitor act as a RF bypass
component. It effectively "shorts" the high frequency signals to ground
while not effecting the low frequency audio.
19. Install Q2, 2N3904 NPN transistor [marked 2N3904]. Pay attention to
the orientation!
20. Install R3, 10K ohm [brown-black-orange].
21. Install R1, 2.2K ohm [red-red-red].
22. Install R2, 10K ohm [brown-black-orange].
23. Install R6, 270 ohm [red-violet-brown].
24. Install C1, 10 µF electrolytic capacitor. Watch the polarity!
25. Install R4, 10 K ohm [what colors were those ??!!] [brown-black-
orange].
26. Install C11, .01 µF disc capacitor [marked .01 or 103 or 10nF].
AM1
10

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