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At yesterday's Barnsley Radio Rally (sorry I mused you John Bradley), I came across this guyhttp://www.copperisland.biz
I was so impressed by this innovative method of prototyping or one off building. Ideal for phono stages for example, or modules like Constant Current Sources and Sinks / regulator circuitry, all thiose solid state add ons which are encroaching these days.
Also viable for small valve bases, ideal for Nuvistors.
I bought a pack, what strikes me of particular value to us is the ground plane effect, do all your grounding to this in tact ground plane, shortest route possible for all grounds. This has to be ideal for us guys.
Follow Ups:
This technique seems to be well established in ham radio builders,
check the followinghttp://www.qsl.net/k7qo/manhat.html
http://users.easystreet.com/w7zoi/bboard.html
Looks like a cool idea to me! Only question that comes to mind is how much capacitance is there between the stick on pad and the ground plane underneath? Could be something to watch in high Z circuits.
Capacitance between pads and the groundplane undoubtedly exists but it is so small as to be hardly measureable on my workshop digital capacitance meter. Some constructors have successfully used the copper island technique to construct equipment operating as high as 144Mhz and 430Mhz without encountering problems, so I cannot envisage any problems occurring at audio frequencies.
Phew glad you answered that. I was about to get the text books out and prove zero capacitance because the distance between plates vis a vis size of plates was so enormous. Basically the pads are too far from the ground plane to consider cpacitance a likelyhood.
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I bought some PCB counterbore "pad" cutters, which drill a 1mm hole and cut a groove leaving a pad 3.5mm diameter with the 1mm hole in the middle. Also a 1.8mm/7mm version. My 6922 phono stage using this approach and double-sided boards is nearly complete, and a breeze to build. A standard drill bit can be used to clear away the copper from the hole if you DON'T want contact.
The pad cutters are available from Farnell.
Also there are "surf boards" available through DigiKey.com and others:
Dear Paul
What can i say ?
I'm sorry i missed you.Had a lot on my mind(the in-laws were coming round for the first time)and i had to get back almost as soon as i got there.
i did enjoy what i saw though, bought some valve bases for handy money etc
will definetly be going to the rally in Leigh on the 8th
Thanks for the Rally info, that will without doubt keep me soldering.
regards
jonathan bradley
I still prefer copper clad board and teflon push in standoffs . Still if these things work , it'll be easy knocking up prototypes . Good idea about the valve bases , I suppose use the pcb mount , layout would be very simple
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