Network Qslcards

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piace of Li. With the optimum value for LI, the tuning range will be much greater than the 40 meter version. Output power is less. Operation on other bands should be possible. Certainly, 30 meters is a prime candidate.

Initial Checkout

Before applying power to the transmitter, you should make a thorough visual inspection. Check for solder bridges, poor solder connections* melted wire insulation and component leads touching other con-doctors. Double-check all connections to make sure they agree with the schematic diagram.

To ad just the transmitter, you will need a dummy antenna and some way to measure output power. A 47 ohm, 2 watt, carboncomposition resistor can be used in lieu of a standard dummy load for the 3 watt version. Just check it occasionally to make sure it's not getting too hot. If you don't have a wattmeter for this power level, see Figure 5.

The wiper of R5 should be rotated all the way toward the grounded leg. You can check this with an ohmmeter. Next, plug in a key. Make sure it can handle the current if it's an electronic keyer. Keying current is a hefty 500 to600mA at 13,5 volts.

The last step before key-down testing is to connect a 12 to 14 volt DC power source. With C2 at midrange, key the transmitter. The grounded wiper of R5 sets the gate bias voltage to zero and the output level will be very low. It should be less than 1/2 watt, possibly less than 100 milliwatts, depending on the supply voltage. Find the transmitter signal with your receiver. If you can't find the signal, LI may be too large. C2 should shift the frequency over a range of at least 5 or 6 kHz. If not, LI is too small, A very tew FT-243- style crystals may refuse to oscillate if their activity is on the sluggish side. At the risk of sounding tike an advocate of crystal abuse, I have found that a sharp blow from a pencil or similar object brings them to life. Once so "enlightened," they work perfectly until disturbed. I suppose the spring-loaded flr-, T√ČNNG

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