JJJelectronics- 2 band VFO for HF

*FET transistor for oscillator*voltage regulator (Zener diode)* Frequency: Band 1: 3.5MHz-3.9MHz. Band 2: 7.0MHz – 7.13MHzOr Band 1: 7.0MHz – 7.13MHz Band 2: 14.0MHz-14.35 MHzOr Band 1: 14.0MHz-14.35 MHz. Band 2: 21.0MHz – 21.45MHz* 2 way switch* Voltage 10v-14v * Terminal for frequency counter (F-C)*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

R1 100k 1

R2 1.5k 1

R3 150R 1

Transistor, Diode and IC

D1 1N4148 1

D2 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

C5 npo 1

C6 100nf 1

C7,C8 1nf 2

L10 220uH red- red- brawn

Solder wire to J2 as shown

Please solder a piece of wire to link 2 tracks as there was a mistake on PCB

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)*Choose the first band and adjust the frequency to 3.48MHz or *Choose the second band and adjust the frequency to 6.98MHz

*Or choose the first band and adjust the frequency to 13.98MHz*Choose the second band and adjust the frequency to 20.98MHz*Now the VFO is ready to use