Vectronics VEC-1220K - Manual (Page 24)

VEC-1220K/1230K/1240K/1280K Owner's Manual
22
Be sure to correct all errors before moving on. If a careful inspection revealed
that everything is A-OK, you're now ready for the moment of truth!
TESTING AND ALIGNIMENT
Tools And Materials Required For Testing:
Your VEC QRP-CW Transmitter is a "no-tune" design that has no adjustable
alignment trimmers or coils to set up prior to operation. If it's built correctly, it
will work. For initial testing, you'll need the following items:
1. 50-ohm dummy load: Any 50-ohm non-inductive resistor capable of
handling up to two watts will provide a satisfactory transmitter load. If a
dummy load isn't available, you can make one using two (2) 100-ohm 1-watt
metal oxide resistors (Radio Shack 271-152). These should be connected in
parallel across a standard RF connector that will plug into your RF wattmeter
or VSWR bridge.
100 ohm
100 ohm
PL259
2. Power Meter: In addition to a dummy load, you'll need a calibrated RF-
power meter with a low-power range to measure the output of your
transmitter. This provides your best indication as to whether or not the
transmitter circuitry is working properly. If you don't have access to a
calibrated watt meter, an inexpensive CB-type VSWR meter will provide a
relative indication of transmitter output.
3. Telegraph Key: Your transmitter's keying circuit will work with any manual
or semi-automatic key, and with most electronic keyers. To plug into the key
jack, you'll need a standard 1/8" (3.5-mm) stereo phone plug (Radio Shack
274-284). Ground (or common) is connected to the plug's outer sleeve, and
the key line is connected to the plug's tip. A monaural type 1/8" plug will
also work.
3.5 mm Phone Plug
Tip
Sleeve
Ring (not used)
Key
4. Power Supply: Your transmitter will operate from any well-regulated 12-14
volt 500-mA DC (or 0.5 A) power source. Avoid using poorly-regulated or