Ramsey Electronics FZ-146 Specifications download pdf (Page 133)

FX-146 • 133

8. While speaking in the microphone, adjust modulation level (R46) for the

best sounding speech. "Best" is not necessarily the maximum: see the

following note. NOTE: R46 adjusts the FM deviation of the transmitted

frequency. Deviation is carrier frequency swing in step with voice

modulation. If you "over-deviate," your signal will not be stronger.

Instead, the speech will become distorted and "splash" over to adjacent

channels. Deviation is a very important adjustment: "best sounding

speech" will usually result in the proper 5KHz deviation used on VHF

FM.

9. Disconnect power and proceed with completing the transmitter section

(Steps TX15, etc.)

IMPORTANT: If you do not achieve the test results discussed above, there

is no point in doing more work on the transmitter section until the problem is

solved. If you are not able to transmit at least within the same room and

receive on any desired frequency, finishing the transmitter is not going to fix

the problem.

CONTINUE TRANSMITTER ASSEMBLY:

 TX15. Install RF choke L19 (prepared in Stage TC). Notice that the

holes are diagonal from each other. If the choke was wound correctly,

L19 will line up nicely as illustrated.

 TX16. Coil L16 was also prepared in Stage TC. Insertion may stretch the

windings very slightly. Gently press L16 in as close to he top of the

board as possible, leaving about 1/8" clearance. The coil windings must

not, of course, touch the solder plane.

 TX17. Install C61, .001 uf.

 TX18. Install C66, 3.9 pf.

 TX19, Install C79, also 3.9 pf.

 TX20. Install C78, 22 pf.

 TX21. Referring to step TX16 and Stage TC as needed, install L15, the

other 5/16" 2.5 turn coil.

 TX22. Install L18, a .33 uh inductor with axial leads. (L18 looks like a

resistor body with wire wrapped around it and is marked by 2 orange

dots.)

 TX23. Install R45, 82 ohm (gray-red-black), R45 is larger than the other

resistors in your kit, it is a 1/2 Watt size resistor.

 TX24. Install L14, .015 uh, small pre-wound 1/8" 1.5 turn coil.

 TX25. Install C60, 220 uf electrolytic, observe polarity.

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Ramsey Electronics FZ-146 Specifications Page 133