Ramsey Electronics FZ-146 Specifications download pdf (Page 120)

FX 146 • 120

C60 until instructed to do so.

Adjustment Procedure:

1. Check PC board carefully for missed connections, wire trimmings or

untrimmed wires bent down, etc.

2. Connect speaker and DC supply voltage.

3. Obtain or make a non-metallic alignment blade capable of adjusting L7

and C81.

4. Set frequency to the channel you selected for 146.52 MHz Simplex.

5. Turn on the unit and verify normal operation of squelch and volume

controls.

6. Connect an accurate voltmeter to TP1 and adjust L7 for 1.27 volts (1.25

to 1.30 is OK for right now.) In our final alignment in Stage TX, we will

touch up this adjustment for 1.60 volts in TRANSMIT mode at 146.52

MHz.

7. If you have a frequency counter and know how to use it, connect it to

TP2 and adjust C81 for 125.120 MHz. This presumes you have

programmed correctly for 146.52 (146.52 - 21.40 MHz 1st IF = 125.12

MHz). If the frequency is too low and cannot be adjusted any higher, clip

out C80, 39 pf. If you do not have a fine Ramsey frequency counter

(you didn't think we'd mention another brand, did you?) but have

completed Step 6 successfully, you can still verify receiver operation

quite easily. Proceed as follows:

8. Connect your voltmeter to pin 5 of U5. Pin 5 is a corner pin near R104.

You should get a reading of at least 4 volts, this indicates that the PLL is

indeed locked. If there is less than 3.5 volts or no voltage at this point,

the loop is not locked and an assembly error is very likely.

9. If the PLL is locked per step 8 above, it's time to listen to a signal. Since

we have no antenna connected, we'll have to listen to a known signal

from a friend or nearby hand-held. If desired, a connection can be made

to the wire sticking up from the PC board near C71 (that wire will later be

connected to the antenna jack). You may then connect up to a signal

generator or antenna. Adjust the quadrature coil, L1, for the best

sounding audio signal.

10. Disconnect the DC power source before further assembly.

That's about all there is to it. The receiver either works or it does'nt. There is

very little "tinkering" that can be done. If it does not work at this stage, it

would be wise to "double check" and retrace your steps.

HINT: trace your work "backwards," beginning with your most recent steps.

Make sure you thoroughly understand the PLL frequency programming and

have installed the program diodes correctly.

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Ramsey Electronics FZ-146 Specifications Page 120