Specifications

Delta Tune or Clarifier (low crystal side) and the oscillator
(high crystal side) circuit points.
For the SSB radios in particular, it’s very important to adjust all
crystals for the proper frequency. Make all adjustments in the “AM”
mode. There should be enough range with the trimmers for exact
netting, You should then check the USB/LSB offsets. These are
usually ±1.5 to 2.5 KHz, as measured at the output of the tuned
circuit which does the multiplication. Adjust the offsets according to
the radio service manual, using the standard FCC band, Clarifier at its
midrange. When switching to the new crystals, the existing offset
adjustments should shift them by about the same amount. The
Cybernet PLL02A SSB chassis uses trimmer capacitors for the offsets,
while the Uniden SSB chassis types use coils to trim the offsets.
EXAMPLE A: Cobra 140/142GTL Uniden chassis. This uses an
11.1125 MHz tripler crystal. New crystals might be 10.9625 for the
lower 40, 11.2625 for the high 40, and 11.4125 MHz for the high-
high 40 channels. For 10 Meters, use 11.5575 MHz (28.300 to
28.740 MHz) or 11.4575 MHz (28.000 to 28.440 MHz) depending
upon your need for the USB or CW/USB parts of the band.
EXAMPLE B: Cobra 148/2000GTL, Uniden GRANT/MADISON
chassis. The existing crystal is a tripler, 11.325 MHz. New crystals
would be 11.175 for the lower 40, 11.475 for the high 40, and
11.625 MHz for the high-high 40 channels. For 10M, use 11.770 or
11.670 for USB or CW/USB respectively; coverage as shown above.
NOTE: The 11.325 MHz crystal used in some older Cobra chassis is
the oversize HC/33 type, not the standard HC/18 case. For CB
expansion you’ll also have to replace that one, since the HC/33 won’t
fit in the EXPANDER 160 PC board.
EXAMPLE C: Cybernet PLL02A SSB chassis (Telsat SSB140,
J.C. Penney 6247, etc.) The existing crystal is 10.0525 MHz and is
doubled. New crystals would be 9.94 MHz for the low 40, 10.165
MHz for the high 40, and 10.2775 MHz for the high-high 40. For
10M, use 10.38625 for USB or 10.31125 MHz for CW/USB.
EXAMPLE D: Early generation Cybernet PLL02A AM chassis with
the 11.8066 MHz crystal. (Midland 13-857B, 13-882C, G.E. 3-
5810B, Kraco KCB2320B, etc.) This crystal is being tripled. New
crystals could be 11.6567 MHz for the low 40, and 11.9567 MHz for
the high 40 channels.
TYPE 3 INSTALLATION — All AM or AM/SSB PLL Radios with
Direct Frequency Mixing
See the previous page. The oscillator output is coupled through a
small disc capacitor or tuning coil to the Mixer stage. You often have
a choice of using the EXPANDER 160 in its SWITCH mode at point
“A” like previous examples, or in its OSCILLATOR mode at point
“B.” We suggest the OSCILLATOR mode. Remove this coupling
capacitor, and place the YELLOW “RF” wire of the EXPANDER 160
in the empty capacitor hole (“B”) that goes to the Mixer side of the
circuit. Remove the original radio crystal, and solder it into the
EXPANDER 160 with the new mixing crystals.
NOTE: In some AM/SSB chassis the SWITCH mode must be used,
because the Clarifier circuit is part of the crystal’s low side.
(Same as the Type 2 sketch, minus the doubler or tripler
stage shown.) Bypassing that would kill the Clarifier! Check
the radio’s schematic to determine the right mode to use.
EXAMPLE A: Any AM Courier model with the REC86345 PLL chip.
The mixer crystal is 36.380 MHz. Use the OSCILLATOR Mode. New
crystals might be 35.930 MHz for the lower 40, and 36.830 MHz for
the upper 40 channels. These are tripler cut (Third Overtone) type
crystals.
NOTE: Many other AM-only PLL radios also use the 36 MHz circuit.
These include those with the SM5104, TC5080, µPD858,
and µPD861 chips, as well as all the Royce “sardine can”
type modular AM models. The same method works in all
these too.
EXAMPLE B: Cobra 29/89XLR Uniden chassis with µPD858 PLL
chip. Either the SWITCH or OSCILLATOR modes could be used
here. However the SWITCH mode is easiest because there is no
coupling capacitor to remove; there is only a PC trace between the
oscillator’s peaking coil secondary and the input to the TR18 FET
Mixer. Rather than having to cut this trace, simply switch in new
crystals along with the existing 36.57 MHz crystal. New crystals
would be 36.12 MHz for the lower 40, and 37.02 MHz for the upper
40. These are also Third Overtone cuts.
EXAMPLE C: Realistic TRC459/TRC480. Because the LC7113 PLL
chip is now extinct and this chassis was very expensive, it’s worth
saving and expanding! The loop crystal is 17.8875 MHz. Use the
SWITCH Mode again, because the Clarifier is on the low side of this
crystal. New crystals might be 17.4375 MHz for the lower 40, and
18.3375 MHz for the upper 40 channels. For 10 Meters, use
18.4825 MHz (CW/USB) or 18.7825 MHz (USB only).
TYPE 4 INSTALLATION — All AM or AM/SSB PLL Radios with
Indirect Frequency Mixing
See Page 5 again. Almost all of these use a 15.36 MHz mixing signal
which comes from the PLL chip itself. The chip has a 5.12 MHz
output pin, and this signal goes through a tripler coil to produce
15.36 MHz which is then capacitively coupled to the Mixer along with
the VCO signal in the 16-17 MHz range. Use the OSCILLATOR
Mode. Remove the coupling capacitor and put the YELLOW “RF”
wire of the EXPANDER 160 in the empty capacitor hole going to the
Mixer side.
NOTE: Because there’s no actual crystal to directly generate the
15.36 MHz signal, you must order this crystal along with the
new ones so you can preserve the standard 40 FCC channels.
Otherwise some complicated switching would be needed to
connect this signal and disconnect the EXPANDER 160
when you want to change bands. For 10M Amateur
conversions, this crystal would not be needed.
EXAMPLE A: Cobra 29GTL/29LTD chassis with µPD2816 PLL
chip. Use the OSCILLATOR Mode. Remove C87 (100 pF) in the PLL
area. Typical new crystals are 14.91 MHz for the low 40, 15.36 MHz
for the standard FCC 40, and 15.81 MHz for the high 40 channels.
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EXPANDER 160 PAGE 6