Kits and Parts Mixers

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K&P ADE Mixer-P1899-720px.jpg

Kits and Parts Mixers - Features in Common[edit]

  • Available as Diode Ring Mixer or ADE-1 || ADE-6 Double Balanced Diode Ring Mixer kits from Kits and Parts
  • LO, IF, RF Ports are all 50Ω
  • +7dBm Local Oscillator injection level
    • As measured into 50Ω load
      • Mixers are not linear and loads should not be measured at the mixer
  • ~5dB RF > IF conversion loss in HF region
  • IF Port
    • Full Diplexer at the IF Port
    • Low Pass Filter can be populated if used as Product Detector / Balanced Modulator
  • Board has pads (1206 SMT or 1/8W resistor pads) for optional Attenuators on RF & LO Ports
  • 3 pin, 0.1" pads at board edges allow SMA edge connectors to be used
  • Mounting holes in all 4 corners

Kits and Parts ADE-1 Mixer[edit]

ADE-1.SCH.png

ADE-1.PCB.png

ADE-1 Schematic[edit]

ADE-1 Schematic.PNG

Performance[edit]

Chart dBm-to-Volts.PNG

ADE-1 Performance.PNG

ADE-1 ElectricalSpecs.PNG

Port VWSR[edit]

  • Measured VSWR of 2.23 at 9 MHz with NanoVNA matches spec nicely

ADE-1 LO VSWR.PNG

ADE-1 IF VSWR.PNG

ADE-1 RF VSWR.PNG

ADE-1 Measurements[edit]

NanoVNA Measurements[edit]

  • No RF in
  • LO driven by NanoVNA Tx
    • About -10dBm output
  • IF output to NanoVNA Rx
  • IF at 9 MHz
    • VSWR: 2.233
    • S21 Gain: -67 dB

ADE-1.NanoVNA LO-to-IF.png

  • NanoVNA
  • No LO in
  • RF driven by NanoVNA Tx
  • IF output to NanoVNA Rx
  • IF at 9 MHz
    • VSWR: 2.216
    • S21 Gain: -42 dB

ADE-1.NanoVNA RF-to-IF.png

  • Scanning from 1 to 100 MHz

ADE-1.NanoVNA RF-to-IF 1-100MHz.png

tinySA Measurements[edit]

LO to IF port isolation[edit]
  • Driven by VFO-001 3.3V squarewave output
    • Signal level about 0.5 dBm
    • CLK0 = 9 MHz into LO port
  • Monitor IF output from mixer on tinySA
    • Output through 20 dB attenuator (tinySA set to -20dB gain)

ADE-1.tinySA RF-to-IF 9Mhz-center.png

Mixer Operation[edit]
  • Mixer is driven by VFO-001 3.3V squarewave outputs
    • Signal output levels about 0.5 dBm
    • CLK0 = RF @7 MHz VFO-001 output with 30 dB attenuator
    • CLK1 = LO @16 MHz no attenuator
  • Monitor IF output from mixer on tinySA
    • IF out to tinySA with 20 dB attenuator (tinySA set to -20dB gain)

ADE-1.tinySA LO-16MHz RF-7MHz-to-IF 9Mhz-center.png

  • Same but 9 MHz picked out
  • Approx. 8 dB insertion loss

ADE-1.tinySA LO-16MHz RF-7MHz-to-IF 9Mhz-at9MHz.png

  • Look at 7 MHz RF freq on IF output

ADE-1.tinySA LO-16MHz RF-7MHz-to-IF 9Mhz-at7MHz.png

  • Look at 16 MHz LO freq on IF output

ADE-1.tinySA LO-16MHz RF-7MHz-to-IF 9Mhz-at16MHz.png

Kits and Parts Diode Mixer[edit]

Diode Mixer Card Schematic[edit]

DBDM.SCH.png

DBDM.PCB.png

Bridged Tee Diplexer[edit]

Diplexor is a bandpass/band-stop filter popularized by Joe Reisert W1JR that is used after a double Balanced Mixer to provide a 50 ohm termination to all frequencies at the mixer's IF port, and to the following amplifier stage. Maintaining a consistent load at the mixer avoids overload and Inter-Modulation Distortion (IMD) effects that these mixers are prone to when not properly terminated.

LTSpice simulation[edit]

  • 9 MHz
  • FT37-67, 20T-12" = 8 uH
  • T37-17, 13T-10" = 250 nH
  • C2 adjusts peak from left to right

DIPLEXER SPICE SIM.PNG

Diplexer.PNG

Diplexer pass.PNG

Toroid Winding Direction[edit]

  • Toroids needs to be wound to match the pad locations/offsets on the PCB

Toroid-cw.jpg

Adjust IF Diplexer C1 (ADE-1)[edit]

  • Drive RF port from NanoVNA
    • Nominal 0 dBm drive level
  • IF port is output
  • No drive on LO
  • 9 MHz is IF design frequency
  • Nano VNA set to scan from 1 Mhz to 30 MHz
    • Shows peak expected signal around 9 MHz

ADE-1.NanoVNA RF-to-IF.png

  • Scan from 8 to 10 MHz
  • Adjust C1 to peak near 9 MHz
    • Eliminate double peaks

ADE-1.NanoVNA RF-to-IF 8-10MHz.png

ADE-1 Mixer as Product Detector[edit]

P1927-720PX.jpg

  • RF is 9 MHz from IF stage
  • LO is 9 MHz BFO from VFO-003
    • Minor adjustments to get to side of the base band offset
  • IF output is audio
    • Mixer goes down to DC
  • IF needs Audio Filter
    • IF port wants to see 50 Ohm termination across output
    • 0.33 uF cap/50 ohms terminates higher frequencies at 50 ohms
    • 1.5 mH inductor in series as filter on audio output
  • LTSpice Simulation

LP Audio-2.PNG

  • Circuit Mods

ADE-1 AF Filter-2.PNG

  • IF section

ADE-1 AF Filter Physicals-4.PNG

Typical Application[edit]

MIXER TEST.png

Si5351A Drive Level[edit]

  • Si5351A used to drive LO and/or RF ports
    • 3 outputs
    • LO at full level (+7dBm)
    • RF at various levels with attenuators to drop to expected RF signal levels
  • Don't want more than 7 dBm into LO or RF ports
  • Two Si5351 Designs to drive ADE-1 LO or RF ports
    • VFO-001
      • Uses the Si5351 without external drivers
      • Set drive levels to 2mA, 4mA, 6mA or 8mA
    • VFO-003 - Adds 50Ω drivers
      • Level is fixed
      • Three 74AC14 parts with 150 ohms outputs paralleled
      • 13 dBm output
      • Install 6 dBm attenuator on board (13-6=7)

VFO-001 drive[edit]

  • The RMS value is for square-wave voltages whose pulse duration (ti) and pause (tp) have the same length:

RMS-SquareWave.PNG

RMS-SquareWave-2.PNG

  • Drive level of 3.3V

RMS-SquareWave-3.PNG

  • 100 mW is 20 dBm
  • ADE-1 needs 7 dBm level
  • Would need a 13 dB attenuator
    • Not actually true
      • Although the Si5351 datasheet says it drives 50 Ohms loads this is not exactly the case
      • Drive levels are controlled by the output current setting
  • Si5351A outputs measured on VFO-001
    • Drive Level 2 mA = 0.2 dBm
    • Drive Level 4 mA = 6.2 dBm << Use this level
    • Drive Level 6 mA = 9.7 dBm
    • Drive Level 8 mA = 11.7 dBm

VFO-003 drive[edit]

  • RMS Voltage of square wave

SquareWace-3.3V.PNG

  • dBm Calculation

SquareWave-3.3V dBm.PNG

  • Expect 14.3 dBm drive
  • Measured 12.6 dBm with NanoVNA - Pretty close
  • Need a 6 dB attenuator on the LO input to reduce VFO-003 for Level 7 mixers (like the ADE-1 mixer)
    • 6 dB 150-36-150
Mixer with SSB4 IF Crystal Filter[edit]

TinySA ADE-1-MixerwCystalFilter 9MHz center.png

  • Scan from 1 to 30 MHz
  • Note other signals are now well into the noise floor of the tinySA
    • LO present but down

TinySA ADE-1-MixerwCystalFilter 1 to 30MHz.png

  • 16 MHz LO level
  • 16 dB lower with crystal filter

TinySA ADE-1-MixerwCystalFilter 16MHz LO-Suppression.png

Mixer with CW5 IF Crystal Filter[edit]

TinySA ADE-1-Mixerw CW5CystalFilter 9MHz center.png

  • Scan from 1 to 30 MHz
  • Note other signals are now well into the noise floor of the tinySA
    • LO present but down

TinySA ADE-1-Mixerw CW5CystalFilter 9MHz 1to30MHz.png

  • 16 MHz LO level
  • 16 dB lower with crystal filter

TinySA ADE-1-MixerwCW5CystalFilter 16MHz LO-Suppression.png

Mixer with CW3 IF Crystal Filter[edit]

TinySA ADE-1-Mixerw CW3CystalFilter 9MHz center.png

  • Scan from 1 to 30 MHz
  • Note other signals are now well into the noise floor of the tinySA
    • LO present but down

TinySA ADE-1-Mixerw CW3CystalFilter 9MHz 1to30MHz.png

  • 16 MHz LO level
  • 16 dB lower with crystal filter

TinySA ADE-1-MixerwCW3CystalFilter 16MHz LO-Suppression.png

Videos[edit]