SLIM-MXR-2 rev B
Mixer with Diplexer
Updated 6-13-08.  Updated to reflect Revision B
Updated 8-11-09.  Add information and revision history

SLIM-MXR-2, Mixer, size-A
Use your mouse's "right click" and "Save Link" to download:
a. 
SKSLIM-MXR-2.sch Rev B, Schematic, in ExpressPCB software.
b.  LAYSLIM-MXR-2.pcb Rev B, Layout, in ExpressPCB software.  Use this drawing to locate the parts on the SLIM Board.
c.  PLSLIM-MXR-2.txt Rev C, Parts List in text format.
d.  PWB-MXR-ADE.pcb Rev 0 Base artwork for PWB, in ExpressPCB software.  Use this drawing to order the pwb from Express.  This is the base configuration for design of the SLIM-MXR-1.  Click to get full information for a basic mixer design on the PWB-MXR-ADE page.

    SLIM-MXR-2 has been designed specifically to be used in the MSA for its Mixer 1 position.  J1 is the Local Oscillator input port.  J3 is used as the RF Input port.  J2 is used as the down converted IF output port.  Pin 2 of the ADE-11X is connected to its internal diode bridge, which is responsive down to 0 Hz.  This module can be used in other applications, but it is probably better to use the basic PWB-MXR-ADE and custom design the components for your specific application.  Minicircuits specifies the conversion loss at -7.5 dB.  I measured the conversion loss at -6.5 dB.
    C25 is a low value capacitor to allow only high frequencies to pass.  The strange looking circuit in the I port path is a diplexer.  Wide band frequencies (and noise) exiting the mixer at the I port "see" a dual path at the junction of L15, C16.  Frequencies higher than 33 MHz follow C16 and get absorbed by the 50 ohm load at R17.  Frequencies lower than 33 MHz follow L15 and are launched at J2.  This gives the mixer a constant 50 ohm load over a very wide frequency range, making it very "happy".  The diplexer could be re-designed for any frequency crossover point.
    The Revision B added a 2.5 dB attenuator in the J1, LO input port.  This addition makes the Mixer's L port a better 50 ohm match.
  This attenuator makes it necessary for the LO Drive into the module to be approximately +9.5 dBm.  For lower drive levels, ie, +7 dBm, the attenuator should be removed.  However, I have tested this module with as little as +4.5 dBm at J1 (+2 dBm on the ADE-11X's L port) with only an additional -1 dB of conversion loss.  The upgrade from SLIM-MXR-2 Rev 0 (or Rev A) to Rev B is quite simple.

Revision History
Original Release: Released 7-08-2007
SLIM-MXR-2 Rev 0, SK-MXR-2 Rev 0, PWB-MXR-ADE Rev 0, PLSLIM-MXR-2 Rev 0

Revision A:
SLIM-MXR-2 Rev A, SKSLIM-MXR-2 Rev A, PWB-MXR-ADE Rev 0, PLSLIM-MXR-2 Rev A  Added a 2 pF chip capacitor to the mixer pin 6 junction to ground (C9 position).  This helps match the mixer to the 50 ohm drive on J1.  Rev A is obsoleted by Rev B.

Revision B: Revised 6-11-08
SLIM-MXR-2 Rev B, SKSLIM-MXR-2 Rev B, PWB-MXR-ADE Rev 0, PLSLIM-MXR-2 Rev B
1.  Deleted the Rev A modification.  Remove the 2 pf capacitor, C9.  Step 2 of this change makes the capacitor, unnecessary.
2. 
Added a 2.5 dB attenuator network in the L port path to the mixer.  This provides a better impedance match between the LO input connector -  J1, and the mixer, which, improves the mixer isolation.

Revised
9-08-2008: errors on Parts List, revised to PLSLIM-MXR-2 Rev C. No other changes.
SLIM-MXR-2 Rev B, SKSLIM-MXR-2 Rev B, PWB-MXR-ADE Rev 0, PLSLIM-MXR-2 Rev C

SKSLIM-MXR-2, Schematic of SLIM-MXR-2
slim/skslim_mxr_2.gif

LAYSLIM-MXR-2, Parts locator for SLIM-MXR-2
slim/layslim_mxr_2.gif  slim/mixer2.JPG
    The photo does not show the
new attenuator circuit added in Rev B.