Tuesday, 27 March 2012

QRPme Sudden Storm

I recently built two versions of the Sudden Storm receiver by W1REX.

The first version I built was the version 4, this was a short lived version - I think Rex, W1REX, once told me he had 45 PCB's available to go out in the field. The version 4 Sudden Storm PCB is red due to a mistake - it was meant to be blue!

The build was very easy and the PCB soldered very nicely, even though I used lead free solder. There is a trace missing from the Tune pot, so this had to be added using a jumper.

Sudden Storm ver4 PCB. See if you can spot the trace fault!
I thnik the rig looks quite smart with it's red PCB, it's a shame that the band module isn't red also. I used the 'soup up' potentiometers which have transparent, hollow shafts. A 3mm LED fits into the shaft so it can be illuminated. In previous rigs I have used blue LEDs, but I have found them to be very bright. Even running them at a very low current doesn't seem to dim them much! This time around I got hold of some purple LED's, I think they look cool because they mostly look blue, but the reflected light is purple, they are a nice intensity too.
Sudden Storm version 4 'red' (Why does John West print his labels upside down?)

 The version 5 board went together extremely well, there are no mistakes on the PCB and the components are very nicely laid out. Again I used the 'soup up' pots with purple LED's. You can see the LEDs sat in the rear of the pot shafts in this photo taken during construction.

 When I had finished the build, I sat the PCB on an old John West tuna tin and applied power. The rig seems to have very low noise, which I think is due to the special filter applied to the LM386. The tuning range is quite limited, but it will work well with a crystal controlled transmitter using the same crystals as the receiver. The crystal can be pulled by an optional capacitor if required. The receiver can be put onto a different band by changing the band module and crystal.

Rex, W1REX, usually supplies a tin, indeed the components are usually sealed inside and you have to open the tin to get the parts out! To save on shipping costs my kits came without tins. Luckily, tuna tins seem to be a standard size all over the world, so my John West tins are just the job. (Thank goodness my wife eats tuna!)

73 de Colin

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