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JJJelectronics- 1 band VFO – HF frequency

*FET transistor for oscillator* zener diode regulator * Frequency: Band: 1.8MHz-1.95 MHz OR Band: 3.5MHz-3.9MHz.Or Band: 7.0MHz – 7.13MHzOr Band: 14.0MHz-14.35 MHzOr Band: 21.0MHz – 21.45MHzOr Band: 5.0MHz – 5.5MHzOr Band: 5.5MHz – 6.0MHz

* Voltage 10v-14v * Terminal for frequency counter*Variable capacitor with 20:1 reduction drive(10 full turns)

Tool required.Soldering iron (25w-40w), small cutter, trimming tool

Now let’s build the VFO

I would recommend fitting the parts in the order they appear in the part list.Resistor first, then semiconductors, coils and Capacitors.Make sure you put the electrolytic capacitors and diodes in the right way round .keep all components leads as short as possible.

When you have finished assembly of the board, check all the parts are in the right places.The soldering looks bright and good. Re-solder any suspect joints with a little fresh solder, check that there are no short or splashes of solder between tracks.

Resistors

R18 100k 1

R14 150R 1

Transistor, Diode and IC

D6 1N4148 1

D9 Zener 8.2v 1

Q6 Bf245 1

Please check the polarity of each diode they should be installed in the board as the outline printed on the board shows

Capacitors/ inductor

C42 NPO 1

C47 100nf 1

C35, C38 1nf 2

L10 220uh red-red- brawn

Miscellanies

Testing*You need oscilloscope or frequency counter *Connect a power supply to +12v and GND*Connect an oscilloscope or frequency counter to the output of VFO*Turn the variable capacitor to the minimum (clockwise)* adjust the frequency to 3.48MHz or

* adjust the frequency to 6.98MHz or

* adjust the frequency to 13.98MHz or* adjust the frequency to 20.98MHz or

* adjust the frequency to 5.0MHz or* adjust the frequency to 5.5MHz

*Now the VFO is ready to use