Friday, July 30, 2010

Ensemble Kit Build Re-Started

As part of a group project, a lot of the members of the Puget Sound QRP Group (pQRP) are building the "Softrock RX Ensemble Kit" for our group exploration of Software Defined Radios (SDR).

As reported in a previous post, I had a false start of my build while at Salmoncon. My goal was to get it started, finished and tested before leaving the event, but that did not happen. With more time now, I plan to continue the project.

Wednesday night, while at our last pQRP P&C (Pie and Coffee) Meeting, Alen asked a few questions about my build process and progress, he asked;

Could Reflow Techniques be used to build the Kit?
  • That Depends, If you want to follow the build instruction the answer is probable - NO. 
  • The instuctions include intermediate voltage and current tests before successive parts are installed. Also parts are installed on both sides of the PCB with through hole and SMT parts added for each test. 
What size of Soldering Iron should be used?
  • My glib answer was; If you can see the tip, use the next size smaller! 
  • But it depends, on the technique used for soldering. To use flood solder with solder wick clean up larger tip (maybe 1/16 inch) could be used. Flood Solder is where you drag a puddle of solder and lots of flux across a group of pins, then remove excess with solder wick. 
  • I use single pin soldering with very little solder wick clean up. I use a small 1/64 inch tip for most of my SMT work. 
As per the instruction, I have the 12 Volt Power Supply, USB, Local Oscillator (Si570) and Control Circuits installed. The next steps include; down loading Firmware to the PIC, loading Software onto the PC and doing some initial tests for proper oscillator operations. I just need some time to do the tasks.

At the P&C meeting, Charlie - took the following incredible photo of my partially completed board. Note, this photo was taken with a hand held camera while setting at the table, with the board propped up on a coffee mug, a setting sun beam provided the light.

Si570 Local Oscillator and USB Circuit

Charlie with his Cannon S90 camera takes great photos in very adverse conditions.

If I had known that a photo was going to be taken, I would have cleaned the board with alcohol, to at least remove rosin splatters. I am looking forward to a completed board photo.


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