NOTE: Limited supply left
as of late 2014. Please email us first before ordering.
See Order Form for prices.
For specific hookup info by model number, see the detailed Installation Instructions &
Technical Notes.
SICK OF CHANNEL BLEEDOVER
INTERFERENCE ON YOUR
CB?
We have The Answer—the CHANNEL
GUARD. A unique active IF filter that wipes out CB radio's most annoying
problem once and for all.
Fits all PLL or crystal CB radios using a 7.8 MHz or
10.695 MHz IF frequency.* Usually installs in minutes with common tools and no
special knowledge. Connect the left & right bare wires to IN & OUT along the
I.F. signal path. (We tell you exactly where.) Connect the middle bare wire
and the long colored wire to the radio's GROUND and +DC power. That's all there is
to it!
Works on AM, FM, and SSB.
CB radio is popular. Maybe even too popular. Either the skip cycle
is in, with great DX to crowd every channel, and all the Hams converting CBs to 10 Meters. Or the skip is dead, so every local guy in town seems to be
busy talking to his neighbor at the same time as you. Many stations are overpowered and
overmodulated, and are guaranteed to make your operating miserable with splatter and
bleedover. Fed up with hearing the guy down the street ten channels away? The CHANNEL GUARD
will stop him cold!
We have
two CHANNEL GUARD filters to fit the most common CB IF
frequencies, 10.695 MHz and 7.8 MHz.**
These
high-frequency filters are specially designed for SSB rigs and most newer AM or AM-FM
rigs. Simply unsolder the correct IF coupling capacitor listed in our detailed
instructions, install the INPUT/OUTPUT leads and GROUND, and connect the long colored wire
to +8-13VDC. You are done! Complete instructions are included and are also online at
the link shown above.
NOTE: The 455 KHz ceramic filter we sold for many years has been discontinued due to the
greater use of our sharper crystal filters. Although it was used in nearly all AM
and AM/FM models at the second IF, the first or high IF is typically 10.695 MHz and these
AM CBs can use our 10.695 MHz crystal filter with even better results. That's
because crystals are far sharper than ceramic elements.
Using
the same idea as our original 455 KHz CHANNEL GUARD, the
high-frequency SSB filters combine an IF amplifier stage with two high-Q crystal elements.
You install our filter at an early IF signal point, before the signal branches off to the
separate AM, FM, or SSB detectors. The result—razor-sharp selectivity in every mode.
Since the "Q" (Selectivity Factor) of a crystal is many times higher than the
normal tuned IF transformers in a CB, the strength of interfering signals even slightly
off the center frequency drops off very quickly. Bleedover is greatly reduced. See the
Graph.
FEATURES:
· Provides up to 100 dB adjacent-channel rejection. This is much
better than most CBs, which typically specify only –40 dB to –60 dB. A
factor of "100 dB" means that any signal outside the normal 10 KHz CB
channel spacing is reduced in strength by a factor of 10 billion from channel
center. Turn your ordinary rig into a hot performer!
· No reduction in receiver sensitivity. In fact, the CHANNEL GUARD
adds one stage of amplification at the most critical point—right in between IF
filtering stages. You may even hear those weak signals that you missed before.
· Every REACT monitor needs one to eliminate Channel 9
bleedover.
· Quality components used. Each CHANNEL GUARD
is hand-made and thoroughly checked against a powerful 30,000 µV modulated test
signal. Just solder it in and
forget it!
* Most CBs use these IF frequencies. The
dual-conversion SSB rigs with a 455 KHz IF only use that frequency for AM or FM;
otherwise nearly all SSB types are 7.8 MHz or 10.695 MHz. The AM-only or AM/FM-only radios
almost always use a 455 KHz low IF, and our 10.695 MHz filter will usually work in
these at the first IF location. If in doubt, send us an email or a large stamped SASE with
the exact radio model and we can advise you what works and how to install it.
** There are also some
older SSB radios with an 11.275 MHz high IF. Models include JC Penney, Lafayette,
Sears, and others. For these CBs we still have a limited supply of 11.275 MHz
monolithic (3-lead) crystal filters that greatly improve their selectivity. If
interested send us your mail or email questions or model numbers.
SPECIAL NOTE:
Our 10.695 MHz filter really cleans up all the Uniden, Cybernet, and RCI/Ranger
“export” radios, and all the CB &
10-Meter lookalikes (HR2510/HR2600, Cherokee, Connex, Eagle, Galaxy, Ham Int'l, Magnum,
Mirage, Northstar, Ranger/RCI, Superstar, TriStar, etc.) And in every mode! See Pages 4-6 of the online CG
HOOKUP LIST,
Manufactured by:
CBC INTERNATIONAL · P.O. BOX 30655 · TUCSON AZ 85751 U.S.A.
TEL/FAX: 888-I-FIX-CBs (1-888-434-9227), (520) 298-7980
Electronic Mail:
To send us an email now, click here.
here
ORDER NOW!
HOME CONTACT US