Homebrew 40m Rockmite

So what do you do with all the components you have salvaged from scrap electronic equipment? The answer; build a transceiver? Also, I have never really used Manhattan or ugly style, construction so it was time to find out if it worked.

After the fun with the Smallwonder Labs SW+20 I decided to try another of their designs, the Rockmite. The circuit looked straightforward; a crystal oscillator, two more transistors for the TX and a couple of ICs to make a DC (direct conversion) receiver.

The RX offset capacitor is to the right of the board.

Most of the components I already had but a few were need from a local supplier. A couple of days later the RX was built and it worked first time. The TX and switching followed and after correcting a wrongly wired transistor it also worked producing around 500 mW.

As I did not have to keyer/switching chip I connected a key to short out the T/R line. That worked fine except there was no RX offset. The answer, hold a 22pf capacitor across the varicap on receive while trying to avoid touching the leads which produced a loud buzz.

I managed a QSO with MW0MWL. Not great DX but for a lash up on the bench with handheld RX shift it was not bad! Now all I need is the keyer chip and a nice little box and it should be QRPp fun time again!

(Click image to enlarge)

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