Updated 6-13-08.  Updated to reflect Revision A
Updated 1-08-09.  Optional modification to minimize high frequency mismatch when using the SLIM-MXR-1 in the Modular Spectrum Analyzer (MSA)
Updated 8-11-09.  Add information and revision history. Describe optional attenuator on J2 port.
Updated 1-20-16.  Move Parts List to this page.

SLIM-MXR-1, Mixer, size-A
Use your mouse's "right click" and "Save Link" to download:
SKSLIM-MXR-1.sch Rev A, Schematic, in ExpressPCB software.
b.  LAYSLIM-MXR-1.pcb Rev A, Layout, in ExpressPCB software.  Use this drawing to locate the parts on the SLIM Board.  Do not use for ordering the pwb from Express.
c.  PLSLIM-MXR-1   Parts List. Maintained only on this page.
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.

    The SLIM-MXR-1 is configured with the Minicircuits, ADE-11X.  This mixer has only a fair L port to R port isolation (mixer pin 3 to pin 6).  Minicircuits specifies it as -38 dBc, but I measure it closer to -30 dBc at 1000 MHz.  They specify the conversion loss at -7.5 dB.  I measured the conversion loss at -6.5 dB.  I continue to recommend this mixer, but only because of it's very low cost.

Updated 7-23-09
LIM-MXR-1 has been designed specifically to be used in the MSA for its Mixer 1 position.  J1 is the Local Oscillator input port.  J2 is used as the RF Input port.  J3 is used as the up converted IF output port.  Module J2 is Pin 2 of the ADE-11X, which is connected to its internal diode bridge. It 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.
SLIM-MXR-1 is used with the MSA, I recommend that it be constructed to Rev A, with the addition of the optional input attenuator modification (see next paragraph).  I also recommend the optional R port Modification (see bottom of page).  The SLIM-MXR-1 Rev 0 is very easily to upgrade to Rev A.

Updated 7-23-09Optional Input Attenuator Modification
    This is not shown in the schematic but an attenuator can be added in the J2 path to make the
SLIM-MXR-1 a better 50 ohm load to external signal sources.  R15 is replaced by a pi-type attenuator with resistor values to conform to the wanted attenuation.  Components not shown are the input shunt resistor, R11 and output shunt resistor, R19.  Locate these components on the Layout, later on this page.  For example: a 6 dB attenuator would consist of R11=150 ohms, R15=37.4 ohms, and R19=150 ohms.

Revision History
Original Release: Released 7-01-2007
SLIM-MXR-1 Rev 0, SK-MXR-1 Rev 0, PWB-MXR-ADE Rev 0, PLSLIM-MXR-1 Rev 0

Revision A: Revised 6-11-08
    Added a 2.5 dB attenuator network in the L port path (J1) to the mixer.  This provides a better load match from the driving module (PLO 1).  This also improves the internal mixer isolation.  With this mod, the L to R port isolation will approach the specification of Minicircuits.
    This attenuator makes it necessary for the LO Drive at J1 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.

Revised 9-08-2008: errors on Parts List, revised to PLSLIM-MXR-1 Rev B. No other changes.

SKSLIM-MXR-1, Schematic of SLIM-MXR-1
    The coupling resistor R15 is a short circuit (zero ohm resistor), allowing all frequencies to pass.  C25 is a low value capacitor to allow only high frequencies to pass.

Parts List, PLSLIM-MXR-1
Revision B,  9-8-2008  (updated 1-23-2016)
Desig.   Value       Part Number                                    Digikey Number                 Cost                        Notes
C5                                                                                                                                             "Rev A, deleted 100 pf"
C25  100 pF   C0805C101K5GACTU                                399-1121-1-ND                   0.05
J1      SMA     optional Molex, 538-73391-0070                  WM5544-ND                      4.74
     SMA     optional Molex, 538-73391-0070                  WM5544-ND                      4.74
     SMA     optional Molex, 538-73391-0070                  WM5544-ND                      4.74
R1     330         MCR10ERTF3300                               RHM330CHCT-ND                 0.04      was MCR10EZHF330/RHM330CCT-ND
R5     15           MCR10ERTF15R0                               RHM15CHCT-ND                  0.04     was MCR10EZHF15.0/RHM15.0CCT-ND
R9     330         MCR10ERTF3300                               RHM330CHCT-ND                 0.04      was MCR10EZHF330/RHM330CCT-ND
R15     0           MCR10EZHJ0.0                                     RHM0.0ACT-ND                  0.08
MXR               ADE-11X                                                    Minicircuits                       2.95
PWB              Circuit Board PWB-MXR-ADE                                                              3.28

LAYSLIM-MXR-1, Parts locator for SLIM-MXR-1
slim/layslim_mxr_1.gif  slim/mixer1.JPG
This layout shows the L port attenuation but no other modifications..  The picture shows the original circuit.

Updated 1-08-09.  Optional R port Modification
     When this module is used in the MSA, the user may find that the Spectrum Analyzer's Magnitude Gain versus Frequency may have an abrupt change at some frequency below 400 MHz.  This is due to the Coaxial Cavity Filter path creating a mismatch for Mixer 1 at frequencies other than the prescribed First Intermediate Frequency of 1013.3 MHz.  This mismatch can be minimized with a simple modification to the SLIM-MXR-1 module.  The schematic, layout, and parts list will not be revised for this modification, since it is optional.  Use the general PWB layout below, to perform the Modification procedure:
1.  Add a 1 pfd capacitor in the X26 position.  This is the ADE-11X, R port, pin 3.
2.  Add a 49.9 ohm resistor in the X27 position.  The value is not critical, from 43 to 62 ohms is fine.
These two series components act as a load for high frequency reflections from the Cavity Filter.