My Mini-Julius (Un)Box
                     
                            all credit to Murph, WV4R and Julius, W2IHY



I just wanted to show my implementation of Murph's Mini-Julius Box.

I use a Behringer MX-802A mixer feeding the mic input of an FT-1000MP or feeding the balanced modulator 
directly of a Ten-Tec Corsair.  The Mini-Julius (Un)Box provides ground isolation as well as level matching.
The level matching I worked out provides proper audio drive such that a 0 dB signal output from the MX-802A
fed through the appropriate Un-Box drives either rig properly.

Please refer to WV4R's Web page.  I  found that I had to vary the values of the two voltage dividing resistors
in the secondary circuit to provide the level matching that I sought. In  his circuit diagram, I have replaced 
the two voltage divider resistors as shown in the following table.  The 2.2K secondary loading resistor is 
unchanged. 


WV4RN1EU's
FT-1000MP		N1EU's
Corsair


10k pot100k10k


820150333


I've  used metal film resistors because of their alleged superior audio characteristics. Like WV4R, the transformer 
was provided by W2IHY. Note that my resistor values result in considerably more attenuation than WV4R, and these 
resistor values aren't suitable for rigs requiring more mic drive. I encourage you to experiment and optimize the 
voltage divider resistor values for your own rig.  

I use 1/8 in. mini jacks for the audio interconnects in my shack.  Instead of wiring this interface into a
box like WV4R, I decided to wire it into a Radio Shack 42-2472A audio extension cable with a mini jack on
one end and a mini plug on the other, thus creating an in-line interface cable: output from MX-802A into
the jack and the plug into the mic adapter of my FT-1000MP or other radios.  Here's what it looks like.  You
should cover the transformer and connections with a piece of large heat shrink tubing or electrical tape.


close up of connections, primary on bottom


tie wraps provide strain relief


Finished product, ready for covering

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