Difference between revisions of "Kits and Parts Mixers"
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[[file:ADE-1.NanoVNA_RF-to-IF_1-100MHz.png]] | [[file:ADE-1.NanoVNA_RF-to-IF_1-100MHz.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]] | ||
== Videos == | == Videos == | ||
Revision as of 10:12, 1 October 2021
Contents
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
- 7 MHz RF, 40 M band
- 16 MHz LO
- Si5351A square wave drive, 50 Ohm source impedance, 1.65V peak
- 9 MHz IF feeds Crystal Filter
Kits and Parts ADE-1 Mixer
- Kits and Parts Mixer
- Build and tune diplexer first
Toroid Winding Direction
- Toroids needs to be wound to match the pad locations/offsets on the PCB
ADE-1 Schematic
Performance
Port VWSR
- Measured VSWR of 2.23 at 9 MHz with NanoVNA matches spec nicely
Kits and Parts Diode Mixer
- Double Balanced Diode Ring Mixer Kit
- Build and tune diplexer first
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
- 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
- Scanning from 1 to 100 MHz
Bridged Tee Diplexer
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
- 9 MHz
- FT37-67, 20T-12" = 8 uH
- T37-17, 13T-10" = 250 nH
- C2 adjusts peak from left to right
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
- Scan from 8 to 10 MHz
- Adjust C1 to peak near 9 MHz
- Eliminate double peaks
Videos
