Gauss Master power switch modification :

The gauss master power switch is a push button on the side of the
unit. Depressing the button and releasing it activates the gauss master
for a  period of time in the  1 to 10 MG range.  The unit times out
after a few minutes , to save battery power , and shuts off.  If you depress the
switch and hold it , the meter is activated in the most sensitive  0 - 1 MG range
and when you release it , it reverts to the 1 to 10 MG range and times out as above.

It would be handy to be able to  " lock " the gauss master in either the high
or low range and have it stay there until you are ready for it to turn off.  This
way you can turn it on and sit it down and do other things and not mess with it
and it will remain on as long as you want.

First  remove the battery compartment cover and lay it aside. Remove the 4 screws
holding the back on , lay them aside.  Look at the back of the gauss master and locate
the  rear of the front panel meter and it's two solder tabs.



Carefully unsolder the two meter tabs with a low wattage iron as to not damage the delicate
meter parts.  carefully lift up the tabs as seen in the picture above.  They are delicate and
care needs to be taken so they won't break off.

Now  lift up the whole circuit board assembly , taking care not to damage or pull the
two wires ( one red , one black ) that go to the front panel speaker. ( Your stock
Gauss Master will not have the jack shown at  the top of this board. This is the
external antenna mod mentioned elsewhere .  A yellow coil will fill the open board
area seen here with a jack and two wires in it.  )




We will be installing either two switches  or a single switch, depending upon how you
want your  gauss master to operate , below is a gauss master with the 2 switch mod.



Using your soldering iron or drill,  make two holes in the side of the gauss master
and mount two Radio Shack spst mini toggle switches as  seen below. They are mounted
with down being off and up being on.

 
The push button on the circuit card basically connects 9 volt power from the battery to
two circuits. one being the  0 to 1 MG circuitry and the other being the  1 to 10 MG
side / operation timer.  We will connect our switches so that the lower one sets
the meter to " on " in the 0 to 1 MG range, and the upper one sets the meter to
" on " in the 1 to 10 MG range.  Use either one or the other at one time. Leave the
other , unused one, in the off position.  ( Doesn't matter except the unit will always stay
in the 0 to 1 MG range if both are in the on position. )  Solder a  wire on two of the
switch pins , one on each switch ( to one, jump to the other and then to the 9 volt
pad below. Solder a wire from the empty top switch pin to the 0 to 1 MG pad seen below.
Solder the last wire to the other empty switch pin to the pad marked 1 to 10 MG below.




Set the card back in place and temporarily replace the battery . Check the switches for
proper operation. Remove the battery, solder the meter pins back in place ,
and reassemble the meter.  That completes the " two switch modification.  

This same modification can be performed using a single  spdt , center off  mini toggle
switch instead of the two mini switches if you like. the 0 to 1  MG range down and the
1 to 10 MG range up is suggested.