Hi, I've been lurking for a while, but its time for a first post.. Some background, and 2 related questions:
My breadboard (2x Busboard 630) is mounted to a 1/4" thick MDF base using the backing adhesive. I am building a Sandspur and prototyping some mods with BC108s and getting a decent amount of background noise, hum, hiss, RF, etc., all the usual in a FF.
From my reading, I need a ground plane. To test if it helps, I took an old license plate stuck it under the base and ran alligator clips from the ground bus to the bare metal. The noise floor was noticeably lowered! I then tried with aluminum foil with nearly the exact same result.
So, before I take things apart or buy anything that won't be an improvement, this brings me to my questions:
1) Everything else being the same, would replacing the aluminum foil or license plate (i.e. aluminum) with copper sheet or foil tape improve the shielding properties?
2) As I mentioned the breadboard is adhered to the MDF and the ground plane is under the MDF, so more than 1/4" away from the bottom of the breadboard.. Would it help to put the foil closer to the breadboard.. i.e. on top of the MDF - and directly under the breadboard? When I lift the base off the foil, I can hear the noise floor increase as the distance increases, but unclear if that first 1/4" matters.
In summary, putting aluminum foil under my MDF breadboard base and grounding to it was a definite improvement. But before I peel off the adhesive and redo, I am trying to determine if getting the plane closer to the breadboard and/or using copper foil would be a significant step above what I have.
Thanks!
My breadboard (2x Busboard 630) is mounted to a 1/4" thick MDF base using the backing adhesive. I am building a Sandspur and prototyping some mods with BC108s and getting a decent amount of background noise, hum, hiss, RF, etc., all the usual in a FF.
From my reading, I need a ground plane. To test if it helps, I took an old license plate stuck it under the base and ran alligator clips from the ground bus to the bare metal. The noise floor was noticeably lowered! I then tried with aluminum foil with nearly the exact same result.
So, before I take things apart or buy anything that won't be an improvement, this brings me to my questions:
1) Everything else being the same, would replacing the aluminum foil or license plate (i.e. aluminum) with copper sheet or foil tape improve the shielding properties?
2) As I mentioned the breadboard is adhered to the MDF and the ground plane is under the MDF, so more than 1/4" away from the bottom of the breadboard.. Would it help to put the foil closer to the breadboard.. i.e. on top of the MDF - and directly under the breadboard? When I lift the base off the foil, I can hear the noise floor increase as the distance increases, but unclear if that first 1/4" matters.
In summary, putting aluminum foil under my MDF breadboard base and grounding to it was a definite improvement. But before I peel off the adhesive and redo, I am trying to determine if getting the plane closer to the breadboard and/or using copper foil would be a significant step above what I have.
Thanks!
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I've used cookie tins in the past.
