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Tuesday, 23 December 2008


At FDIM 2008 I had a few chats over lunch with Ted Bruce editor at QQ who later sent me a couple of these MOSFET and I said I'd work them into a little qrp amp of some sort. (And write it up for QQ of course!).
Here are some preliminary images of the PCB fabrication after the ugly looking prototype worked.
The production method uses press n peel blue film (glossy photo paper also works) and an iron on transfer to PCB before etching. So using Express PCB ( I create a PCB layout. Print it out onto paper and cut out the layout. Then tape a square of Blue Press n' Peel film onto the reverse of the paper where the layout has been cut out.

I am playing with output transformers so I have used either T106 or a pair of stacked BN43-202 or BN43-202 on the PCB hence the complicated component layout, but no extra tracks or holes. The T106 or BN43-302 or 202 were picked up from W8DIZ at FDIM but you can order online from him at

Feed it into the laser printer:

And hey presto one PCB mask for transfering onto a fresh piece of PCB.

Expecting to get some time in the shack this Xmas I have pre made up these boards and a few others so I can make a fresh batch of etch and take that down with me.

The PCB will be about 2" square. Note there are NO LPF components fitted to this PCB they will be needed. The populated PCB will be fitted onto the lid of a Jack Daniels minature tin and I am using a 1U solid copper PC CPU heatsink and fan for cooling. The RD16HHF1 will be mounted under the board.