FX 146
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10
ENCLOSURE & HARDWARE CONSIDERATIONS:
The companion CFX case and knob kit is sold as a separate option ONLY
as an accommodation to those radio hams who have their own ideas or
resources for the "finishing touches."
However, a proper case for your FX-series is much more than a "finishing
touch," since the controls and jacks are panel mounted and proper RF
shielding is required.
The CFX case measures 9-3/4"L X 6"W X 1.5"H. 9" x 6" dimensions are
minimum for accommodating the PC board. The height may vary if you wish
to include an internal speaker, accessory PC boards, additional front panel
controls or indicators, etc. If you are new at all this and do not already own a
suitable enclosure plus that collection of hardware and knobs that every ham
seems to accumulate, here is what you need to know if you are hesitant to
purchase the CFX case kit:
A. "Blank" electronics enclosures have become among the most
expensive hardware in the industry, especially if you are buying just one
unit. This is because they are sold mainly to engineers and designers
for prototyping. A blank metal enclosure even slightly comparable to the
CFX case kit will run $30 to $80 or more. Even a plain aluminum
chassis box/cover will be around $15.00.
B. If you think there's any chance you someday may wish to sell or trade
your transceiver, you should be aware that units mounted in odd boxes
may have even less value than the bare circuit board with
documentation alone.
C. Many distributors have a minimum mail order of $25.00.
D. Your best chance for finding an inexpensive alternative case is to have
access to a lot of ham friends who tend to "collect stuff," or to browse
the catalogs or showrooms of electronic surplus dealers. You just might
find a gorgeous new box originally intended for somebody's ingenious
Ultra Modem, external disk drive or other dream gadget from two years
ago.
Are we trying to discourage you? No, not really! We know you can see that
there are good reasons to consider calling Ramsey Electronics and getting
your CFX case on its way while you work on the PC-board and PLL
Programming. However, we do not want you to feel "stuck" with our
recommended CFX enclosure, so we have worked up a detailed shopping
list for getting what you will need to make as attractive a finished unit as
possible with a single trip to the neighborhood Radio Shack store.
FX-146
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137
This completes the assembly of the low pass filter PC board. Inspect the
board to be sure all leads on the bare side of the board are trimmed neatly
and that the coils do not short against the PC board ground plane.
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TX45. Exactly when to install the SO-239 antenna RF connector is left to
your discretion. If you are using your own case, you must now "wing it"
on your own, observing the way we are mounting the connector to our
case. If you are using the Ramsey CFX case set, mount the SO-239 to
the rear panel as part of this assembly operation. Use the two screws
and four nuts supplied and consult the illustration as needed. The flange
of the connector sits on the outside of the rear panel. Mount the
connector with one set of nuts, then mount the low pass filter PC board
using the other two nuts. Solder the connector center pin to the board.
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TX46. Line up the two ground wires and C63, the .01 uf coupling
capacitor, on the low pass filter board with the mating holes on the main
FX PC board. Allow the low pass board to stand about 1/8" above the
main FX board and at a neat right angle. Solder the leads to the main
FX board, be careful so as to not loosen the solder joints on the little
board from too much heat when soldering - if you do, just retouch the
solder joints again, it's no big deal!
TRANSMITTER COMPLETION AND TUNEUP
Do not proceed with the following until all of the previous steps have been
completed successfully. You now have a somewhat fragile assembly, the
rear panel being held to the main PC board with only three wires, please be
careful during the next few steps.
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TX47. Install L10, an orange wire coil that appears to have 5 turns when
viewed from the top.
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TX48. Install R32, the remaining 1/2-watt 82 ohm resistor. (Larger body:
gray-red-black).
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TX49. Install RF choke L9, reviewing Section "TC" and Step TX15, if
necessary.
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TX50. Connect the following to your transceiver:
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50-ohm dummy load
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VHF RF wattmeter or voltmeter connected to R115, the stand up
resistor test point on the low pass filter board.
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DC 12 volts power
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TX51. Press (key) the transmit button and alternately adjust C84 and
C74 with a non-metallic alignment tool for maximum RF output indicated
on the meter. If you are using a voltmeter connected to the resistor test
point, you will typically see about 12 to 15 volts when connected to a
