FX 146
•
38
FX-146 PROGRAMMING SUMMARY
Programming your FX-146 is really quite simple; all it takes is a clear mind, a
scratch pad and a calculator. In closing, let's find the proper N value for a
common NOAA weather channel, 162.55 MHz.
First, find N: 162550 ÷ 5 = 32,510 Then, convert to binary:
Can we subtract 32,768? NO
Can we subtract 16,384? YES 32,510 - 16,384 = 16,126
Can we subtract 8,192? YES 16,126 - 8,192 = 7,934
Can we subtract 4,096? YES 7,934 - 4,096 = 3,838
Can we subtract 2,048? YES 3,838 - 2,048 = 1,790
Can we subtract 1,024? YES 1,790 - 1,024 = 766
Can we subtract 512? YES 766 - 512 = 254
Can we subtract 256? NO
Can we subtract 128? YES 254 - 128 = 126
Can we subtract 64? YES 126 - 64 = 62
Can we subtract 32? YES 62 - 32 = 30
Can we subtract 16? YES 30 - 16 = 14
Can we subtract 8? YES 14 - 8 = 6
Can we subtract 4? YES 6 - 4 = 2
Can we subtract 2? YES 2 - 2 = 0
Can we subtract 1? NO
We're done! Install diodes in all YES positions, and no diodes elsewhere.
BASICS OF EXTERNALLY CONTROLLED FX-TRANSCEIVER
FREQUENCY SWITCHING
The 12 front panel switched channels, with never a need for a crystal will
cover most applications generously. Yet many of us will want to figure out
ways for easy frequency-programming of still more channels, especially if we
do a lot of cross-country travel. Rather than endorse or illustrate any
particular scheme, of which there are dozens if not hundreds, we provide
here the most basic schematic information needed to set up any kind of
auxiliary switching correctly. The principles and requirements remain the
same whether you use DIP switches, toggle or slide switches, electronic
latching or go all out to build the mother of all diode matrixes. Make sure
whatever you build resembles electrically the diagram on the page 39.
Some DO's and DON'Ts of FX-Transceiver Add-Ons:
1. DO study and understand the basic switching diagram.
2. DO let your ingenuity run wild to come up with the neatest, most cost-
effective scheme.
3. Please DON'T ask our technicians to talk you through your own idea.
FX-146
•
109
Stage H: Frequency Programming, Understanding and Building your
Diode Matrix
