Thursday, August 24, 2017

N6QW Simpleceiver revisited updated 8/26

Over a year ago I was working on a version of Pete N6QW's Simpleceiver and my version of a SMD Bitx.  Then Farhan came out with his amazing Bitx40 board.  I dropped my original projects and went to work on the Bitx40 with a homebrew SI5351 VFO.
Now Pete has returned with the Simpleceiver Plus and has plans of eventually converting it to a transceiver.  From the response Pete has received, it looks like there is quite a bit of interest in this project.

I think I will revisit the Simpleceiver and restart on what I had been doing.  Pete is doing this with simple building blocks that can be reused for several functions in his design, and also other projects.
Taking the product detector and audio amplifier circuit published on his blog, I started doing simple circuit boards for each of these.
Because the boards can be combined into a larger assembly, I am using expressPCB software to design the boards.  They will be laid out for etching using the toner transfer method.  I also decided to do two versions of each board, one using leaded components and another for size 1206 SMD .  Checking my available parts, some of the parts used will be have to be leaded, so I have made provisions for using them in both versions.

The first circuit Pete  published was for a dual J310 product detector, this basic circuit will be used several times in the final system.  The leaded version is laid out similar to K7QO's "Muppet" style with fairly large pads for mounting components.  I also placed large ground pads to help align components, and to make soldering to the ground plane a little easier. The SMD version is laid out larger than it could be, but I wanted to make it easier for construction without a solder mask.

Pete has several different audio amplifier circuits, a LM386 version and a higher power LM380 circuit. I will probably go with the LM380 version, but will build both and test to see which one I like best.  I have the LM380 version layout finished, and hope to get the LM 386 version done in a day or two. 

Finished the LM386 version of the audio amplifier board and generated toner transfer image files for both versions.   I am putting all these files in a dropbox folder at

In the next couple of days I plan on etching and building up some boards.  Then I can test them and see which one I want to use for the final project.

Wednesday, August 2, 2017

New 3D Printer Project

|My poor little 3D printer has been busy for the last week or so printing parts for its big brother.  The AM8 design is based on a bunch of mods to the Anat A8 copy of the Prusa I3.  There have been several different versions of parts created to build the AM8 by different people.  Just looking at the files, I was not able to determine which would work the best for my build.  I ended up printing several different versions of several parts and then will decide which version I wanted to use for my project.  As I stated before, the original AM8 design used 2040 Aluminum extrusion for its frame. I did not have any of that profile, but did have some 2020 and decided to go with that.  Because I did not want to redesign a lot of the parts, I will sister two pieces of 2020 to get the desired profile.  Unfortunately I did not have enough Aluminum extrustion, so I printed some 2020 profile out of ABS.
After 4 days of 18 hour prints, I had enough 2020 profile finished to build the pieces I need.  After Acetone welding them together, I was pleased with how they looked and also how strong they were.
After cutting them and the Aluminum extrusion to length, I started the assembly.  The combination of Aluminum and ABS profiles went together very easily, and fit with the other printed parts very well.  After trying some of the different versions of parts I printed, I came up with what will work best for my project.  Because of some of these choices, I had to design and print several additional parts.  

After assembling the frame and gantry, I am very pleased with how it looks and how strong it is.  The size is just right to sit on the file cabinet next to my computer desk.
Now I am waiting on several other parts to arrive to complete the assembly of the X axis and Extruder carriage.  After that I can start on the motors, and electronics.  So while I am waiting on them, I can work on the boards for the SNA Jr 2.8 that came in last week.