Ramsey Electronics FZ-146 Specifications download pdf (Page 113)

FX-146 • 113

Even though there are 16 matrix positions to program, there are some

shortcuts to make your job easier for normal ham band operation. Let's look

at the upper and lower band edges for the 2 Meter band:

Notice that the values of the highest 6 positions are the same throughout the

band. We still must program in those six positions but we only need to

calculate for the remaining 10 (512 through 1).

Let's look again at the programming of 146.52 MHz Simplex, where N =

29,304. First, we see that the 16K, 8K and 4K positions are always

programmed with a diode and that the 32K, 2K and 1K positions never have

a diode installed. Let's put that fact to practical use:

1. We will always install diodes in the 16K, 8K and 4K positions.

This gives us an 'initial' N value of: 16,384 + 8,192 + 4,096 =

28,672

2. This number can be used to START programming ANY

frequency within the Amateur 2 Meter Band. We need only add

additional diodes in the 512 through 1 positions for the various

channels within the band.

3. We determine these additional diodes by the same "Descending

Attempted Subtraction," that we used above for studying the

programming of 146.52 MHz Simplex, a process which you can

do in your head, with scratchpaper, or on the FX146

Programming Worksheet.

Let's do an example:

1. We're already familiar with the right answer for 146.52 simplex,

let's use it again. N = 146520 ÷ 5 = 29,304

2. Since we have already installed diodes in the 16K, 8K and 4K

positions, our 'initial' N is 28,672. The N we need is 29,304.

3. We now figure the difference between the N needed and the

'initial' N: 29,304 - 28,672 = 632

4. Now, using the "Attempted Subtraction" technique, find the

remaining binary value to be programmed.

1 2 ... 108 109 110 111 112 113 114 115 116 117 118 ... 144 145

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Ramsey Electronics FZ-146 Specifications Page 113