Description:
The local oscillator modulates from 98.2 - 118.7
Note: You must use a general purpose VHF transistor in this curcuit on the NPN transistor labeled "VHF".
1. Find a good spot for your gang (the AF circuit must be right beside it.)
2. Identifiy the pins on the gang
** The lighter pf
part of the gang
should go to the oscillator, the heavier side goes to the loop; don't
mix them up!
Look at construction tips for more information.
1 goes to the AF curcuit.
2 and the locator lead goes to Positive.
3 goes to the local oscillator.
4 Make sure you look at construction tips.
3. Build the circuit shown on the side; the first transistor is the oscillator the second is the isolator amp.
4. Once your circuit is built put a frequency counter on the output.
5. Turn the oscillator, and Antenna Filter trimmer on the back of the cap to there midpoint
6. Turn the gang to it's lowest point "87.5", and spread out the three turn coil until you acheve a little lower than 98.2MHz (you might have to cap it down with a 5pf capacitor).
7. Turn the gang to it's highest point "108MHz" and turn the trimmer until you achieve a little over 118.7MHz
8. Repeat step 6 until the range just under 98.2Mhz and just over 118.7 MHz
9. Connect the output to the mixers Local Oscillator in; make sure the "detector gain" is at it's midpoint and the volume is up.
10. Connect about about 3 feet of wire to the mixers AF side and you should be able to tune some local stations; if you can't there is something wrong.
Note: You must use a general purpose VHF transistor in this curcuit on the NPN transistor labeled "VHF".
1. Find a good spot for your gang (the AF circuit must be right beside it.)
2. Identifiy the pins on the gang
** The lighter pf
part of the gang
should go to the oscillator, the heavier side goes to the loop; don't
mix them up! Here is a data sheet of a BC-88 Gang cap (doctored) from www.oselectronics.com most gangs use this pin configuration.
Look at construction tips for more information.
1 goes to the AF curcuit.
2 and the locator lead goes to Positive.
3 goes to the local oscillator.
4 Make sure you look at construction tips.3. Build the circuit shown on the side; the first transistor is the oscillator the second is the isolator amp.
4. Once your circuit is built put a frequency counter on the output.
5. Turn the oscillator, and Antenna Filter trimmer on the back of the cap to there midpoint
6. Turn the gang to it's lowest point "87.5", and spread out the three turn coil until you acheve a little lower than 98.2MHz (you might have to cap it down with a 5pf capacitor).
7. Turn the gang to it's highest point "108MHz" and turn the trimmer until you achieve a little over 118.7MHz
8. Repeat step 6 until the range just under 98.2Mhz and just over 118.7 MHz
9. Connect the output to the mixers Local Oscillator in; make sure the "detector gain" is at it's midpoint and the volume is up.
10. Connect about about 3 feet of wire to the mixers AF side and you should be able to tune some local stations; if you can't there is something wrong.