QRP-80
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16
27. Install varactor diode D4, observe flat side placement.
28. Install R3, 1 megohm (brown-black-green).
29. Install R4, 10K (brown-black-orange).
30. Install C2, 330pF (marked 330 or 331).
31. Install C3, 470pF (marked 471 or 471).
32. Install R6, 470 ohms (yellow-violet-brown).
With the above components installed correctly, the three holes for Q1 should be
clearly apparent. Make sure Q1 is correctly identified as a 2N3904.
33. Install Q1, 2N3904. Orient its flat side correctly.
34. Install C5, .01µF (marked .01 or 103 or 10nf).
35. Install R7, 100 ohms (brown-black-brown).
36. Install C4, .01µF (marked .01 or 103 or 10 nf).
37. Install R5, 10K ohms (brown-black-orange).
38. Install C6, 100pF (marked 100 or 101).
It's time to decide which crystal(s) are to be installed in which position and to
install at least one of them for testing. Notice that there are two pairs of holes
for each crystal connection, so that you can install virtually any standard crystal
case style.
HALFTIME SUGGESTION
It won't be too much longer before your Ramsey transmitter is ready for testing
and on-the-air operation. It is common for experimental projects to give
disappointing results because of inefficient "haywire" hookups as soon as they
are completed. This is most especially true with low power transmitters! To try
out this transmitter, you will need the following, and we'll offer suggestions
about each of them:
◊
A healthy and CLEAN source of 12-14 volts DC, connected with
CORRECT POLARITY
. A power supply or battery capable of 500 mA is
required.
◊
A receiver capable of CW reception on the same band as this transmitter,
with a coaxial antenna line terminated in a plug or adapter to mate with the
receiver jack on this transmitter.
◊
A resonant antenna with a 50 ohm coaxial feedline such as RG58,
terminated in a plug or adapter to mate with the RCA antenna jack on this
transmitter.
◊
A CW key, keyer or computer interface connected to a cable terminated in a
Summary of Contents for QRP-80
Page 6: ...QRP 80 6 that will become obvious ...
Page 11: ...QRP 80 11 BLOCK DIAGRAM ...
