H-MODE HIGH LEVEL SWITCHING MIXERS FOR HF WITH FST3125M IC 

IT CAN ACHIEVE AN OUTSTANDING IIP3(input IP3) around  +40dBm  to  + 42dBm equal to an OIP3 (output) of +35 to +37 dBm with  5dB of insertion loss in the HF range and IF at 9MHz (for input signals  level range up to +5dBm).  Isolation between ports is good and OL power required is around  0 dBm and +5dBm much less than for passive high level diode mixers. DO NOT LEAVE Floating the LO input when powering ON the
board. With AC SOIC IC logic Total Power Supply Current, with LO generator connected with signal at 0 dBm, is around 22 mA at 5,000 Volt.

  " A Doubly Balanced "H-mode" Mixer for HF  " 
By Sergio Cartoceti, IK4AUY

my article  is  in July/August 2004 QEX (ARRL ) Magazine, pages 23 - 32
(
reproductions only with permission: copyright ARRL, QEX July/August 2004, all rights reserved). This material originally appeared  in QEX:Forum for Communications Experimenters
www.arrl.org/qex


NEW
: Down load here my article pdf file (for personal use only)

       

(Adobe® Acrobat® Reader is required to open PDF files. You can download the Acrobat® Reader for free from the Adobe® Web site).
 

    See QEX
    See QEX
            OK
    See QEX
    See QEX
            OK
    OK
             OK

My 2004 QEX  article is also available inside ARRL Periodicals CD-ROM 2004

More remarks about “A Doubly Balanced “H-mode” Mixer for HF “ article:

About other frequency ranges: in spite i intended to  use this RF Mixer with 9 Mhz IF and  an RF input from 1.8 to 30 Mhz this mixer works  upto more than 100 MHz with 43 type binocular baluns specified, but not tested it for IP3 or ports attenuation balance in that range, and insertion loss could be around 6 or 7 dB instead of around 5 dB (still comparable to a passive mixer). Use AC faster logic 74AC86 (NOT 74HC86 maximum usable up to 50 Mhz).  

Murata datasheet for LCL (5 Volt power supply filter which was not specified in component list but not critical)  EMI FILTER Suppression, 3 terminal, could be a MURATA DSS series straight type with built in ferrite beads with 10.000 pF  100 V  (suffix ending with 103) (or better a  22.000 pF   16V, suffix ending with 223)

www.murata.com
catalog at
http://www.murata.com/catalog/c31/es0150.pdf
A large stocking component distributor I use in Europe is Farnell  (also for FST3125 IC)
(its Murata catalog in http://www.farnell.com/datasheets/6821.pdf)
 

I have also  tested a smaller pcb 51 mm X 36 mm  (unpublished for lack of space in the magazine):  
 a)  h-mode HF mixer all smd (the best in balance, it is always bilateral for both RX-TX), for LO NOT divided.
 


We have also tested:
b)  h-mode HF mixer with a divide by 2 squarer with noise blanker input pulse gate (so a mixer that can be activated as a noise blanker gate in one board)     
                                                      
CLICK HERE TO DOWN LOAD


c)  sample and hold PRODUCT DETECTOR with a complete audio chain  plus our audio final around TDA2003 IC
d) a board with LSB-USB-CW BFO oscillators for 9 MHz used in our evaluating RX tests

Best 73 de Sergio, IK4AUY
                 Romano, I4FAF 

Last update: Nov 25, 2009.