Construction is simple, although care must be taken to insure that all leads are as short as possible. L3 should have its iron-core slug removed. The RFCs are simple 1/2 watt resistors wound full of #36 enameled wire. To check their efficiency, use a grid dip meter to see if you're anywhere near 144 MHz. If they aren't, remove or add turns until the desired frequency (should correspond with your transmit frequency) is achieved. L1 should be neutralized by winding a full solenoid of #26 wire on a 1 meg, 1 watt resistor. Leaving only about 1/2-inch of lead, solder the choke to the crystal socket. It should resonant at your operating frequency.

Main thing is to get the crystal to oscillate. If you have trouble, adjust L2 and expand or compress the turns of L1 until you hear (using a 2-meter receiver) the oscillator harmonic. From here on in you can simply tune for maximum signal using a GDO, field strength meter, or receiver S meter.

• Q1, 2 2N1745 transistor
• C1, 2 .001 mF capacitor
• C3, 4 .01 mF
• C5 50 pF
• C6 12 mF, 5%
• R1 510 ohm resistor
• R2 30K
• R3 10K
• R4 100 ohms
• B1 9vdc battery
• L1 19 turns #24 enameled wire on 1 meg, 1 watt resistor
• L2 9 1/2 turns #24 enameled wire on 5/16 inch slug-tuned form
• L3 6 1/2 turns #24 enameled wire, spaced 1/6 inch on 5/16 inch slug- tuned form
• L4 1 3/4 turns #22 enameled wire on cold end of L3
• RFC1,2,3 #36 enameled wire wound (and glued) on 1/2 watt resistor. Should check to approximately 145 MHz with GDO. If it doesn't, adjust number of turns. (Ohmite Z-144)
• X1 72 MHz 5th overtone crystal
• SW1 SPST switch

            ---L1---
            |      |
            |      |
------------*--X1--*------------
|                              |
|                              |
*------------E-Q1-C------      C1
|              B        |      |
|              |        )      |
R1             |     L2 )------)------C6---*---E-Q2-C-------   -----C5---ANT
|              |      ^ )      |           |     B         | ^ |
|              |      | )-------           |     |         ) | (
RFC1           |      | )                RFC2    |       L3) | (L4 
|              |        )                  |    GND        ) | (
|              |        |                  |               |   | 
GND     -------*--R2-*--*                 R4         ------*   |
        |      |     |  |                  |         |     |   GND
        |      |     |  |                  |         |     |
       C2     R3    C3  |                GND        C4    RFC3
        |      |     |  |                            |     |
        |      |     |  |                           GND    |
      GND     GND  GND  |                                  |
                        -----------------------------------*---SW1--B1+--GND