Plug-In BITX Modules

Anyone who reads these notes will already know that I like plug in modules for solder-less breadboards. Here's a couple more to add to my fleet...

I've been playing around with some ideas for cheap 'n dirty SSB generation and I needed a broadband amp - so I thought I'd make up one using the bidirectional design from the BITX. I enjoyed making it so much I made a matching mixer with integral driver too...

The amp is one of the standard building blocks from the BITX...

I spent some time figuring out a layout on a scrap of Veroboard - trying to fit it onto a piece 12 holes wide (as that's the best width to work with on my breadboards).

Here's the layout I came up with (seen from the "component" side - the red "x's" indicate breaks in the copper tracks)...

and here's the finished article...

Flushed with the success of that module (and needing a mixer) I made up the second unit, implementing this section of the original BITX design...

Again, I wanted it on a piece of perforated board 12 holes wide, so I kept to the same overall size - here's the layout...

and here's the mixer in vivo...

Needless to say, the little modules work fine (after I'd remembered to make the last break in the copper track on the mixer circuit - my forgetfulness was causing an obscene amount of current to flow and making a 100 Ohm resistor get very warm).

No doubt the big boys will tell you that Veroboard and (in particular) solder-less breadboards aren't the thing for RF work. I don't care - they're really useful for trying out quick ideas and kludging systems together to see if things work.

With the added flexibility that these little ready-made modules bring, playing with RF is - literally - play.

...-.- de m0xpd