Difference between revisions of "Kits and Parts Mixers"

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[[file:DBDM.PCB.png]]
 
[[file:DBDM.PCB.png]]
 
== Bridged Tee Diplexer ==
 
 
Diplexor is a bandpass/band-stop filter popularized by [https://www.youtube.com/watch?v=iVUv8C-8g-Y 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 ===
 
 
* 9 MHz
 
* FT37-67, 20T-12" = 8 uH
 
* T37-17, 13T-10" = 250 nH
 
* C2 adjusts peak from left to right
 
 
[[FILE:DIPLEXER_SPICE_SIM.PNG]]
 
 
* [https://www.changpuak.ch/electronics/calc_16a.php Diplexer Calculator (Bridged Tee) Diplexer Calculator]
 
* [https://www.qsl.net/g3oou/mixerterminations.html Mixer Diplexer description]
 
 
[[file:Diplexer.PNG]]
 
 
[[file:Diplexer_pass.PNG]]
 
 
<video type="youtube">zOk_0IiIgZY</video>
 
 
=== Adjust Diplexer C1 ===
 
 
* Drive RF port from NanoVNA
 
* Listen on IF port of NanoVNA
 
* No drive on LO
 
* 9 MHz is IF design frequency
 
* Nano VNA set to scan from 1 Mhz to 30 MHz
 
** Shows peak at 9 MHz
 
 
[[file:ADE-1.NanoVNA_RF-to-IF.png]]
 
 
* Scan from 8 to 10 MHz
 
* Adjust C1 to peak near 9 MHz
 
** Eliminate double peaks
 
 
[[file:ADE-1.NanoVNA_RF-to-IF_8-10MHz.png]]
 
  
 
== Measurements ==
 
== Measurements ==

Revision as of 10:12, 1 October 2021

Kits and Parts Mixers Features in Common

  • All Ports are 50Ω
  • +7dBm Local Oscillator Injection Design
  • Full Diplexer at the IF Port
  • Optional Attenuators for RF & LO Ports
  • Available as bare PCB or kit of parts

My Typical Applications

Kits and Parts ADE-1 Mixer

ADE-1.SCH.png

ADE-1.PCB.png

Toroid Winding Direction

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

Toroid-cw.jpg

ADE-1 Schematic

ADE-1 Schematic.PNG

Performance

Chart dBm-to-Volts.PNG

ADE-1 Performance.PNG

ADE-1 ElectricalSpecs.PNG

Port VWSR

  • 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

Kits and Parts Diode Mixer

DBDM.SCH.png

DBDM.PCB.png

Measurements

  • NanoVNA
  • No RF in
  • LO driven by NanoVNA Tx
  • 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

Videos