Thursday, 16 July 2015

Finishing a few off

Dissapointingly, no parcels arrived today from the Far East, so ive had no new bits to get excited over. I decided instead to finally get a couple of projects boxed up and completed.

First up was the little Chinese 40m Pixie. In the finest tradition of QRP minimalist radios, this got built into an Altoids tin

because of the clearances needed for the sockets, it wasnt possible to have the lid open as it originally did, so this has been removed and the 'hinges' flattened down, it now just clips on. There is space when open to slot a 9v PP3 battery in the tin to power the radio.

Next, was the 40m Sudden-2 kit from Kanga that I helped Sam build a couple of years ago! I had been looking for a suitable box for it. The case selected is a re-purposed Tvonics Freeview Set Top Box case.

The front has a sort of wave shape, but I think it looks quite groovey. I havent bothered to cover the back over, so theres still lots of cut-outs for SCART connectors etc, but some of the other holes have been pressed into service for the power and antenna connectors.

 The only problem was finding some knobs for it! I have a box full of knobs, but couldnt make up a matching set! Either they were of a type that will not secure to the shafts of the controls used in the kit, or they were missing their grub screws. Just where the heck have all my grub screws gone?
Coverage is about 7.05 - 7.15MHz. Sensitivity seems low, -75dBm ish for a decent sound, so will have to check that out. But, I think it looks alright

Other than that, the only other stuff done today has been more of the laser comms circuit mock up. The top section of the breadboard is the 555 timer sawtooth 40kHz generator. Below is where I have started to mock up the 741 op-amp based microphone amp.

The module beside them is a DDS module. When I finally work the pin-out out, this and an LCD module will be mocked up with a PIC chip to create a DDS VFO. I really should get that LCD sorted!

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