Stephen VK2BLQ's Very FB EARLY build of the SolderSmoke Direct Conversion Receiver

 

This was back in the old days, long before we had Discord.  It was early 2023, and we were getting ready to start the Direct Conversion receiver project at the local high school.  I put out a version of the SolderSmoke Challenge:  I asked people to build our receiver and let us know if it worked for them.  Stephen VK2BLQ took us up on this and built the beautiful receiver you see above.  

Thanks Stephen.  Welcome to the Hall of Fame!  

Stephen wrote:  

Bill,

Don't worry, you are not alone out there.

Here is my build; sorry that the front panel is overexposed and hard to see, but it is plywood.

I did follow the schematic but due to the contents  of the junk box there have been some component changes.

The only thing that I had to buy was the 3/16 x 50 mm (2 inch) brass screw.

My calculations for the coils for the PTO and  BPF  were  a little  bit off necessitating padding down the PTO with a further 100 pF (easier than remaking the coil and mounting)  and removing a few turns from the T50-6 toroids.

Like other people have found: the audio takes off at full volume; I am thinking but not yet tried adding decoupling between R5 (15K) and C2(47 uF). It isn't the actual values of the electros as I had to use 100 uF so might be the audio output getting back into the earlier stage.

The tuning range I get is  our 7000 to 7200 KHz and some shortwave stations above and below, Turning the screw is a little bit fiddly, but once tuned the vfo is quite stable and the audio sounds good.

Best wishes,

Stephen

VK2BLQ