The Twins

We were clearing out the brewing closet today, and while moving stuff to the crawlspace I stumbled over my old twins.  The receiver has a couple scratches on the top from where a speaker used to sit, but they are otherwise in visually pristine condition.  I'll have to check them out and see if they still work, they've been packed up for many years now.  I'd love to have get these two running again!

Building the 4SQRP SS-40 Receiver Kit

So, after over 20 years as a ham, it was finally time to build a radio.  After searching for a kit that looked challenging, but still buildable for a beginner, I settled on the SS-40 superhet receiver from the Four State QRP Group.  This little receiver has about 150 parts including 1 surface mount piece, 2 toroid coils, and 1 transformer to wind.  After placing my order on Sunday, I received it on Wednesday, just in time for a 4 day weekend I had scheduled trying to use the last of my carryover PTO from 2012.  When I pulled it out of its envelope, here is what I saw:

The board seems to be really high quality.  While I don't have much experience (built a couple electronics kit in highschool/college, but that was quite awhile ago), the boards markings were easy to read, and the traces are inside the board so no chance of accidentally lifting a trace.  After taking in the sight of what will eventually be a radio, it was time to start inventorying the parts.  After getting everything checked off I was missing one resistor, luckily I did have a spare in my parts drawer so that wasn't an issue.

The directions did not come with the kit, but were online.  After printing them off it was time to get started.  Everything was pretty straight forward and easy to follow.  The build was done in sections.  Below is a picture after adding the controls, the power supply, and audio amp stages.  It only took 2 of my days off to finish building.  I only ran into a couple issues.  I grabbed one wrong resistor, after realizing my mistake I had to desolder and replace it with the correct one.  After that I checked any resistor I wasn't sure about with a DMM just to be safe.  The other issue was due to my inexperience with coils.  When I put on the transformer I hadn't removed enough enamel from the wires.  It was surprisingly hard to remove that piece and I ended up scorching the board a little bit trying to remove it, but in the end it was fixable.  After that there were no issues building the kit.

Finally, everything was built and it was time to test.  It turned out I didn't have any plugs that would fit the power jack so I ended up using alligator clips to hook it to my power supply.  Once I flipped the switch it came to life with signals everywhere.  It really is extremely low noise and sensitive.  At one point I just had a 3ft coax connected and it was able to receive a couple stations with that.  When hooked up to the s9v it is almost wall to wall signals.  It does cross the digital part of 40m also so I recognize the sound of psk31, and even once heard an olivia signal, though I had to tune back and forth since it was wider than the passband of the filter.

Here is what it sounds like when finished.  Sorry for the bad sound, you can hear the lens moving as it focuses on this camera.  I may try to redo the video when I get a chance.

So there you go.  My first attempt at a kit went extremely well and it was an absolute blast to build and now use.  I now have the bug and have ordered a keyer kit.  Now I'm trying to decide if I should get their matching transmitter or go for a transceiver kit.  Since their transmitter is only $32 I'll probably go that route first and have a whole 40m station for a bit over $100.  After that I'm eyeing either the OHR or the Ten Tec 20m or 15m transceiver kits. 

If you haven't ever built a radio, I highly recommend checking out an inexpensive kit like this one.  Building the kit is fun, its a total rush when you first power it up and hear this radio you built pulling in signals, plus you get a decent piece of gear.

Until next time...  73 de N0QBX sk