DEM Part Number 10368-144________
dBG
10_________ MHz Transverter, _______MHz IF, Serial Number ________
Power Out: >3W adjustable LP version: > 10 mW
Noise Figure and Gain: <1.2dB @ 20
DC Power Requirement: 10 - 15.5 VDC @ 2.5 Amp <0.6 Amp
IF Option: Common Split
IF Drive Level Requirement: 1-250 mW 250mW-3W 3-10W Other_____________
Keying Option: PTT - to ground TTL - Positive Voltage
Aux. Connection Output Option: TX RX High Low RVD
Antenna Option: Common (external relay provided) Separate TX & RX
DIGILO 10 MHz Source: Internal --RED LOC External – GREEN LOC
Operational Overview
The DEM 10368-144 is a 3 cm to 144 MHz transmit and receive converter. It has a linear
output power of >3 watts (>10mW for LP version) and may be achieved with as little as 10mW or a
maximum of 10 W of IF drive with the correct IF configuration. The receive section is a design
using 2 stage PHEMT LNA (GaAs MMIC in the LP). The base local oscillator freq uency is
provided by the new DIGILO synthesizer. It operates with an external or its internal 10 MHz clock.
The DEM 10368-144 has a built in transmit / receive relay driver to provide voltages required by
common SMA relays and provisions for external switching so adding a high power amplifier or
preamplifier to your 3 cm system is easy. IF level options have been built into the transverter. The
IF levels are adjustable on both transmit and receive and have a dynamic range of approx. 25dB.
This is useful for adjusting your maximum output power and setting the "S" meter level on your IF
receiver. The IF connections are via BNC connectors. Options have been provided for a key line
input PTT-H (+1 to 15 VDC) or PTT-L (a closure to ground) and auxiliary contacts on either
transmit or receive with a common line for many applications. The control, power, and auxiliary
connections are via DC feed thru connectors and the 10 GHz. connectors are SMA. The 1 036 8144 is housed in our standard 4.125" x 1.875" x 9.75" extruded aluminum enclosure that matches
the all of our other microwave transverters. (LP model measures 4.125” x 1.875” x 7.750”
Connect your transceiver to the transverter:
Interfacing the transverter to the transceiver is easy. First review the assembled
configuration above. If the transverter was configured for direct connection to your transceiver (10
watts or less), follow the steps listed next.
1. Open the top lid of the transverter by removing 4 screws. (two front, two back)
2. Connect all IF cables. The transverter may have a common IF port or two separate ports TXIF
and RXIF. Use good quality coax cable to connect the ports between your transceiv er and t he
IF connectors on the transv er ter .
<3.5dB
/Built/10638-144rD.doc 1 Rev D 3/9/2021
3. Connect the Push to talk line out of your transceiver to the transverter. It is labeled PTT on the
transverter and uses a solder type DC feed through connector. The correct keying type can be
configured for your transceiver at time of order or you may select it in the transverter now by
moving the PTT jumper if required.
4. If the WTR option was not ordered, you will have separate TX and RX ports. You may connect
your own transfer relay at this time or continue interfacing without it. Connect your 3cm antenna
system or a dummy load with a power meter to the appropriate transverter ports. Always
terminate the receive port with a 50 ohm load.
5. Connect the DC power to the transverter. It uses a DC feed through type connector. 13.8 volts
is optimum but the transverter will operate normally from 11 to 15 volts.
6. Preset the TXIF and RXIF gain controls in the transverter. Turn the TXIF contr ol full y count er clockwise and the RXIF fully Clockwise. This is maximum attenuation on Transmit and
minimum attenuation on Receive. (see the TC board component placement diagram for correct
gain adjustments)
7. Power your transceiver “ON” and leave it in the Receive mode on 144.100 MHz (or see IF
frequency selected on Cover Sheet) This should be 10368.100 unless you ordered a different
frequency scheme. The Green “ON” LED and the Red “LOC” LED should be lit. You can test the
internal/external 10 MHz clock by connecting/disconnecting an external 10 MHz source t o the
transverter. This should either produce a Red or Green LOC light.
8. Adjust the RXIF gain control until a slight noise increase is heard in the transceiver or just a
slight movement in the “S” meter is detected. Power the transverter on and off to verify the
change of noise in the transceiver. You may also remove the 50 ohm load to determine receiver
performance. You can find a signal on the band if you have an antenna connected or use a
weak signal source or signal generator to determine correct frequency, or minimum signal level
desired.
9. It is recommended to test the transverter in the CW mode because most transceivers have
carrier level controls in this mode only. Do not use full or semi break-in if possible. Do not use
FM, SSB or AM because it may not be possib l e to obt ai n max i mu m outp ut power with your
transceiver in these modes. Set the carrier/output power control on your transceiver to
minimum or “0” output power. Place the transceiver into transmit. If the PTT circuit is
connected correctly, the transmit LED on the transverter will switch on. While observing a
power meter on the 10 GHz system, slowly increase the carrier control (with key down) or
increase the power output control to maximum on the transceiver. If the transverter is
configured correctly for your transceiver, minimal power may be detected on the power meter.
Slowly adjust the TXIF control in the transverter in a clockwise direction while observing the
power meter. Set it to obtain a saturated power reading and then just back off a little to avoid
total saturation. If a power meter is not available this will be difficult. You may use a current
meter on the DC power line to determine if the transverter is transmitting. A maximum of 2.5
amps should be obtainable and it sho ul d not vary as the TXIF control is adjusted. When
maximum power is achieved the current will suddenly decrease. This is saturation. Back off the
TXIF drive to limit the amount of saturation. Switch the transceiver to USB and make a
transmission. The pow er output and curr ent drain should correlate to your speech pattern.
10. You may re-adjust both RXIF and TXIF again if desired. Do not adjust any of the filters unless
you have access to a spectrum analyzer at minimum. It is also not recommended to adjust the
bias pots of the LNA and power amplifier. They have been optimized.
11. Put the top on the enclosure and install the screws. Your transverter system is ready to use.
Connect as you wish to use it in your 10 GHz system and have fun!
/Built/10638-144rD.doc 2 Rev D 3/9/2021
IF
SMA
TX
Load
Switch
LED
TC
PCB
RX
10 MHz
Synt
9V Reg.
+9
+9
RF Out
RX
TX
Lock LED
Lock
+9 VDC
RX IF
+TX
+RX
10368 Transverter PCB
M2
M1
TX IF
2M IF
10W Max.
+13.8VDC
Synth
TC
3408 MHz. LO
TX RF
RX RF
+LO
10 MHz
External
or Internal
TX
RX
PTT +13.8VDC AUX
GND
IF
PCB
Aluminum
Plate
Pipe Caps
10 MHz
Internal view of LP version enclosure layout.
Wiring Block diagram
/Built/10638-144rD.doc 3 Rev D 3/9/2021
End Plate connector assembly.
C3 1.0 pF
C29 1.0 pF
C44 1.0 pF
C45 1.0 pF
C32 100 pF
C46 5 pF (0805)
R38 Short or 51
C9 1000 pF
C33 100 pF
C47 1.0 pF
U1 N6
C10 1.0 pF
U2 N6
C14 1.0 pF
C37 1.0 pF
D1 HSMS8202
U3 N6
C15 100 pF
C39 1.0 pF
D3 HSMS8202
U4 N6
U5 ERA-5 or N6
C41 1.0 pF
U6 N6
C22 100 pF
U7 N6
C24 1.0 pF
C43 100 pF
U8 N6
C21 100pF(0805)
D2 MMBD914
FB1 Ferrite Bead
C26 1.0 pF
IC1 FMM5061VF
C27 1.0 pF
IC2 NMA0505S
C11 100pF(0805)
C28 1.0 pF
Q1 CE351K2
C12 100pF(0805)
Q2 CE351K2
VR1 78M05
C13 100pF(0805)
Q3 MMBT3904
C16 100pF(0805)
C36 1.0 pF
R4 5.1K
C48 1.0 pF
10368-144LP Transverter Board Parts List
All components are Surface Mount. All resistors are 1206 size unless indicat ed. All
capacitors are 1206 size except for 1.0ρF are 50mil ATC. All others are as indicted.
R7 51 Ω R33 51 Ω
C5 0.1µF C30 0.1µF
C8 0.1µF
R12 100 or 51 Ω R34 36 Ω
R14 36 Ω
R20 51 Ω
C34 0.1µF C49 0.1µF R23 36 Ω
R25 51 Ω
R26 36 Ω
C17 0.1µF C40 0.1µF R1 51 Ω R27 75 Ω
C20 0.1µF
R2 51 Ω R29 51 Ω
C42 0.1µ R5 36 Ω R30 36 Ω
R6 36 Ω R31 51 Ω
10368-144 3 watt version additions.
All chip resistors are 1206 size unless indicated. All 1.0pF capacitors are ATC 50mil. 10.0 µF
is a tantalum and white band indicates positive polarity.
C1 10.0µF
C50 10.0µF R9 0Ω R24 12Ω(0805)
C2 10.0µF C23 0.1µF (0805)
C4 10.0µF C25 0.1µF (0805)
C6 0.1µF(0805)
C7 10.0µF
C18 0.1µF (0805) C38 0.1µF (0805)
C19 0.1µF (0805)
/Built/10638-144rD.doc 4 Rev D 3/9/2021
C31 10.0µF
C35 0.1µF (0805)
R10 470Ω R28 51Ω(0805)
R11 240Ω R32 51Ω(0805)
R13 5.1KΩ R35 200Ω Pot
R15 5.1KΩ R36 1KΩ Pot
R16 51 Ω(0805) R37 3Ω, 10 W
R17 470Ω
R18 220Ω
R3 0Ω R19 51 Ω(0805)
R21 51Ω(0805)
R8 0Ω R22 51Ω(0805)
C45
C39
C40
C43
R31
R30
U3
F6
U4
F5
U5
F4
C29
C30
C33
R25 R26
C41 C42
R33 R34
D3
D1
R2
F3
U2
F2
U1
C44
R38
(Add for Standard
Version )
R23
R7
R6
C8
C10
C22 C17
C14
C47A/B U6
F9
U7
F8
U8
C3
R1
R5
R14 R20 R27 R29
C5
C9
C15
C20 C24 C32
C34
C37
C46
LO IN
10224MHz TP
+9
VRX
RX IN
RX IF
TX IF
VTX
VTX
TX OUT
10368-144LPrC TRANSVERTER SCHEMATIC
(Sh o rt for Stan dard Version
51oh m (0805) for LP Version )
R12
C49
/Built/10638-144rD.doc 5 Rev D 3/9/2021
Rev C
C48
TX RF
C35
C31
C38
R35
+10 TX
3ohm
10W
F7
FROM
C45
C1
C2
C4
Q3
R13
R15 C12
RX RF
+
C7
+13 TX
F1
TO C44
10368-144
LNA + PA SECTION
06/2020
C28
D
R17
C16
R36
D2
C6
R21
C25
R4
R11
C26
S
G
Q1
R18
C13
C27
R24
R19
R16
D
S
G
Q2
R22
C19
C18
R10
C11
C23
C21
R8
R3
R9
+
R28
R32
R37
C36
C50
/Built/10638-144rD.doc 6 Rev D 3/9/2021
/Built/10638-144rD.doc 7 Rev D 3/9/2021
/Built/10638-144rD.doc 8 Rev D 3/9/2021
DEM Part Number TC
DEM TRANSVERTER CONTROL
The DEM Transverter Control (DEM TC) was redesigned in 2019 to perform with both
separate IF and common IF microwave transverter boards or Mixers and to accommodate the
connections for the DIGILO synthesizer such as frequency switching and “LOC” indication. It is still
our basic “TC” board with the extra hooks incorporated. It is used in every DEMI microwave
transverter 2304 and up and provides the regulated +9VDC, IF switching and attenuation
functions, DC switching functions and external 24 VDC relay driver.
Circuit Description:
The DEM TC circuit board measures 3.75" x 2.15", which is designed to fit all DEMI
microwave enclosures. It is not designed to be a drop in replacement for the original PIN Switch
board. The TC offers all of the functions our microwave transverters require such as providing a
common or split IF operation with up to a 10 watt IF drive level with either a PTT High or Low for
keying. It also incorporates adjustable attenuators for both transmit and receive and has an option
for additional receive gain if required. It will perform all dc switching functions for the tr ansverter
including switching 24 VDC microwave relays. A new optional feature in the TC includes a PIN
diode switch network that connects the TC to a single mixer transverter while still allowing the TX
and RX gain to have independent adjustments. With this new design, the TC is more versatile and
will accommodate other makes of microwave transverters or offer more flexibility for homebrew
equipment.
Operation:
RF Input power to the TC is dependent on the attenuation installed bet ween C5 and C4.
The 50 ohm load resistor is designed to handle 35 watts with proper heat sinking. When mounted
to the front panel of the transverter, it will not tolerate more than 10 watts reliably for a long period
of time. You may experiment with external heat sinking if you desire additional external
attenuation. External attenuation may be used in the transceive path. The added attenuation on
the receive signals may be overcome by adding the RXIF gain stage. The level may be adjusted
with the RXIF adjustment.
The RX/TX IF isolation is ≈ 60dB. The adjustable RXIF and TXIF controls have 20 - 25 dB
of range. Simply grounding the PTT-L line or applying a voltage between 1-15V to the PTT-H input
will switch all RX/TX functions in your transverter and provide external DC switching functions.
The output of the +24 volt relay driver should measure +24 to +28 VDC with no load. It will
measure the DC input voltage of the transverter if it is loaded with a common type SMA relay.
The TC is not designed to be a RF sensed switch. It has 3 relays and it may be connected
to external mechanical relays. If any RF sensing scheme is added to the circuit, it will cause
excessive relay chatter that will not only ware out the relays prematurely, but could cause other
failures to external preamplifiers and or power amplifiers if used in your system. RF sensing
circuits are not recommended with any circuit that contains mechanical relays at RF frequencies!!
/Built/10638-144rD.doc 9 Rev D 3/9/2021
Parts List
Q4 MMBT3904
C3 0.1 µF
C16 330 µF elect.
R2 1K pot
R15 330 Ω
C4 0.1 µF or 1 pF
D1 -D6 1N4000
R3 1K Ω
R16 1K Ω
D7 1N914 or 1N4148
IC 1 MAR6
2 - single LED
K1 G5Y relay
VR1 78S09
C9 0.1 µF
K2 G5V or equiv. relay
R8 220 Ω
50 Ω load
C10 0.1 µF
K3 G5V or equiv. relay
R9 1K Ω
1 pF
Q1 MMBT3904
R10 1K pot
1 – Dual LED
Q2 MMBT3904
C13 4.7 µF Tant
Q3 MMBT3904
R12 330 Ω
All components on this list are 1206 size and are hand solder.
C1 0.1 µF C14 0.1 µF (optional)
C2 0.1 µF C15 100 µF elect. R1 220 Ω R14 1K Ω
R13 10K Ω
C5 0.1 µF
C6 0.1 µF
C7 0.1 µF
C8 0.1 µF
C11 0.1 µF
C12 4.7 µF Tant
D8 1N914 or 1N4148
R4 220 Ω R17 10K Ω
R5 5.1K Ω R18 1K Ω
R6 5.1K Ω
R7 220 Ω
R11 1KΩ
Note: All relays and C16 are installed in the bottom side of board
The optional RXIF Gain stage may be replaced with a 1000 pF 1206 chip capacitor.
Depending on the drive level used, C4 may be a 0.1µF chip, or a 1pF leaded capacitor, a 220
ohm leaded resistor or a variable capacitor.
/Built/10638-144rD.doc 10 Rev D 3/9/2021
/Built/10638-144rD.doc 11 Rev D 3/9/2021
digiLO – A Wideband PLL Synthesi zer
The digiLO is a Wideband Fractional-N / Integer-N PLL Synthesizer based on Maxim 's
MAX2870 capable of generating signals from 23.5MHz to 6GHz. It measures only 2” x 3” and comes
programmed with over a hundre d popular frequencies. A co nnection to an external 10MHz reference is
provided. But the digiLO automatically switches to its on-board TCXO reference when its 10MHz
external reference is not detected.
The recommended supply voltage for “+V” is 9V. But r eli able oper ation is possible down to
7V. The digiLO is tolerant of supply voltages up to 15V. But operation beyond 9V results in
excessive heating of the voltage regulator. So if 12V operation is desired, it is recommended to use
a 27 Ohm 2-Watt resistor in series with the power connection. This should drop the voltage to the
digiLO to a safer level. A +5V direct connection which bypasses the voltage regulator is also
available.
The MAX2870's internal volt age controlled oscillator (VCO) operates from 3GHz to 6GHz. The
MAX2870 generates output frequencies lower than 3GHz by inserting dividers af ter its VCO up to a
maximum of 1/128. Every divider slightly increases the MAX2870's current consum ption. Therefore, the
supply current increases as output frequency decreases. Below 47MHz, supply curre nt is a maximum
of 200mA. And above 3GHz, t he su pply current drops to 130mA.
The 10MHz External Reference should be from a clean and st able source. Keep in mind
that the digiLO's output is dir ectly affected by the quality of its reference. T he recommended input
range for “REF IN” is 0dBm to +13dBm. At levels below 0dBm, the digiLO automatically switches
over to its internal TCXO reference.
When the digiLO is locked to its external 10MHz reference , the “LOCK” output switches from 0V
to 5V through a 200 Ohm resistor . This output can also serve as a simple indication of which reference
(external or internal) is so urcing the digiLO. Up to 20mA can be safely sourced from this connection.
Therefore, a LED can be connected directly from the “LO CK” output to ground.
The RF output of the digiLO appear s on the “RF OUT” connection. The output level is virtually
flat from 23.5MHz up to 2GHz. And i t maintains a level of +2dBm ±2dB up to 3GHz. Beyond 3GHz,
the output gradually f all s to -10dBm at 6GHz.
Further details of the DIGILO Synthesizer can be found at :
http://q5signal.com/image/catalog/digiLO%20Doc%2019_9_1.pdf
The DIGILO in this transverter is set for 3408MHz for 10368 = 144 MHz. If you ordered
some other IF frequency it will be indicated below.
______________________________________________________________________________
/Built/10638-144rD.doc 12 Rev D 3/9/2021
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