Specifications

EXAMPLE B: All late generation Cybernet PLL02A AM chassis with
10.24 MHz and 10.695 MHz crystals. (HyGain 2702, Midland 77-
857, G.E. 3-5804D, etc.) In this circuit, the 10.24 MHz crystal is used
not only for the PLL Reference Oscillator, but it is also doubled to
20.48 MHz and used for loop mixing. Use the OSCILLATOR Mode.
Remove C17 (47 pF) from the chassis and install the YELLOW “RF”
wire in the empty capacitor hole going to the IC2 Mixer. You will
need a 20.48 MHz crystal to preserve the standard 40 FCC channels,
as well as 20.03 MHz for the low 40 and 20.93 MHz for the upper 40
channels.
EXAMPLE C: Early NDI Chassis with MC14526/MC14568 PLL
circuit. (SBE Sidebander IV, Sidebander V, Console V.) Connect for
the OSCILLATOR Mode. This chassis uses a 10.00 MHz crystal for
the PLL Reference Oscillator, which is also doubled to 20.00 MHz for
loop mixing. Remove C918 (1.5 pF). Install the YELLOW “RF” wire
in the empty capacitor hole going to Mixer Q911. You’ll need a
20.00 MHz crystal to replace the removed signal. New crystals could
be 19.55 MHz for the lower 40, and 20.45 MHz for the upper 40
channels. For 10M, use 20.595 MHz (CW/USB) or 20.895 MHz
(USB only). NOTE: The later NDI chassis with the NDC40013 PLL
chip works in exactly the same way. Those models include: Craig
L131, L231, Johnson Messenger 4730, Johnson Viking 4740, NDI
PC200, PC201, Pace 1000BC, 1000MC, SBE Console VI, Tram D64.
EXAMPLE D: The Uniden µPD2824 SSB chassis. You must use the
OSCILLATOR Mode. Currently includes the following models.
PC833/PC965: Cobra 146GTL, Midland 6001(new), 7001 (new),
Midland 79-260, Pearce-Simpson Super Cheetah (Australian),
President AR-144, AX-144, P300, Realistic TRC451,
Sears 663.3810, Uniden PC244.
PB062: Realistic TRC453, Uniden PC122
PB105: Uniden Pro640e
PB122: Realistic TRC465, Uniden Pro810e
These popular models are still being sold. They require some extra
modifications. The following special section is devoted just to them.
Use the Chart below to find the specific part number being discussed
in the text. Look under the columns “A” through “L” for the
particular circuit function. Then substitute that part number as
you’re reading the text. The small parts are located in the wax VCO
mess
IMPORTANT! The SSB Clarifier control will be lost unless you
make the following changes. This chassis was purposely designed to
use the 10.24 MHz PLL Reference Oscillator signal for the SSB offsets
and the Clarifier too. (Precisely to discourage illegal Clarifier mods!)
Special radio modifications are needed to make it work properly with
the EXPANDER 160. The 5.12 MHz PLL tripler signal will be
disconnected. Since you’re replacing it with an external 15.36 MHz
oscillator (plus your choice of others), the SSB offsets and Clarifier
wouldn’t work afterwards. The following steps will solve this
problem, and will also give you much more slide range too.
CRYSTALS TO USE:
14.460 MHz gives 26.065 to 26.505 MHz (LOW-LOW band)
14.910 MHz gives 26.515 to 26.955 MHz (LOW band)
15.360 MHz gives 26.965 to 27.405 MHz (FCC band)
15.810 MHz gives 27.415 to 27.855 MHz (HIGH band)
16.260 MHz gives 27.865 to 28.305 MHz (HIGH-HIGH +10M CW)
16.455 MHz gives 28.060 to 28.500 MHz (10M Novice band)
You can pick a maximum of only 4 of the 6 possibilities!
VCO BROADBAND
1. Replace “A” (47 pF) with a .001 µF disc capacitor. This
increases the control of the VCO varactor diode “F.”
2. Replace both resistors “B” with 180Ω. This increases the gain
of the VCO transistor stage “F.”
CLARIFIER TX/RX SLIDER
1. Remove parts “C.” This eliminates the fixed TX-only control.
2. Replace “D” with a bare jumper wire; this adds an extra
+0.7 VDC to the total varactor control voltage.
3. Use your radio schematic to locate the Clarifier hot side. This is
the end of the pot with the 8 VDC, RX-only normally on it. The
newer chassis use ribbon cables, as the front panel is also a
PC board. You’ll have to trace this conductor very carefully
from the front panel to where it enters the main PC board. Lift
that PCB wire, and put one end of your own wire in that hole.
4. Run the other end of your wire over to “J.” This is the constant
+8 VDC. The radio will now slide on both RX and TX. Check
this out right now, before even installing the EXPANDER 160.
In the next step the 10.24 MHz PLL stage will be modified;
potential problems are much easier to isolate by logical testing of
each step as you go.
REQUIRED RADIO MODIFICATIONS
1. Remove X1, the 10.240 (10.2417) MHz crystal. Solder one lead
of a 4.7µF coil in the empty crystal hole that went to the [-] of
“H.” Leave the other end standing up vertically for the moment.
_________________________________________________________________________________________
EXPANDER 160 PAGE 7
UNIDEN
Chassis
Type
“A” “B” “C” “D” “E” “F”
VCO
Stage
“G”
10.24 MHz
Oscillator
“H”
Clarifier
Varactor
Diode
“I”
10.695 MHz
Mode Offsets
“J”
Constant
Regulated
+8 VDC
“K”
10.240 MHz
Mode Offsets
“L”
TX Tuning
Mixers & RF
PC833
PC965
PB015
C75
(47 pF)
R98
R99
D32
R122
D31 C73
(5 pF)
TR19
L14
TR20
D25
TR22 D30 USB: L20/C102
LSB: L21/C103
AM: L19/C101
Collector
of TR35
(2SA473)
L16, L17, L18
(ignore all)
OSC. = TR22
MIX: L40, L39,
L38, L37
Final: L27
PB062 C72
(47 pF)
R102
R103
D25
R119
D24 C66
(5 pF)
TR20
L13
TR21
D19
TR23 D23 USB: L19/C97
LSB: L20/C98
AM: L18/C96
Pin 3, IC4
(HA17808)
L17, L16, L15
(ignore all)
OSC. = TR23
MIX: L37, L36,
L35, L34
Final: L26
PB105
PB122
C72
(47 pF)
R102
R103
D25
R119
D24 C66
(5 pF)
Q20
L13
Q21
D19
Q23 D23 USB: L19/C97
LSB: L20/C98
AM: L18/C96
Pin 3, IC4
(HA17808)
L17, L16, L15
(ignore all)
OSC. = Q23
MIX: L37, L36,
L35, L34
Final: L26