Topband: Update on noise cancellation

[Ian Keyser]

Having thought long and hard on the subject I have just built and tested a 
noise blanker with exceptional results.

The phase shifter with it's high Z input and output would not suit my low Z 
noise aerial.... I also decided that the IMD of the map would be improved by 
the use of a better amplifier.

For the phase shifter I used two Toko 3333 coils, the output of which drove 
a MAR6 amp.   Output level adjusted with a 1K carbon pot (in junk box).

I could not see the point of the added complexity of a quad filar 
transformer, (coupled with the fact that I have suitable trifilars in 
stock!) so used that.

First test to check sufficient gain in the system I fed the sig gen into 
both inputs and monitored output on the scope.....perfect balanceobtained.

On the aerials and receiver a 9+10 signal could be nulled to S4.

Unfortunately we have had dry weather for weeks not and the power lines not 
making a noise!.... I have to be patient!

Thanks to everyone for all the help and suggestions.

When I have learnt how to upload to my website (friend does it for me.... 
cannot understand computers!!) I will upload my circuit to there

73

Ian.... G3ROO/KG3ROO