Thursday, October 22, 2009

Fifth Generation QRSS Band Edge Marker

OK, I admit it, I have a obsession for small Home-brew electronic projects.

This is the next iteration of my QRSS Band Edge Marker, my goal is to make it even smaller.


Marker - PCB Art Work

This Home-brew PCB is 1.0 X 0.75 inch; with 15mil traces, 10mil GND Grid, 3pt font, and using 1206 parts.

This is a standard Colpitts Oscillator, with my own modifications for stability.

The black thing in the centre is a L78L05 Voltage Regulator - left of it is a 2N3904 SOT-23. On the bottom row, the third component from the left is a GKY50086 4.5-50pF Trimmer Cap. For this oscillator, the trimmer should have been a smaller value and NPO, but this is only value I have a present.

I normally do not like to cut the leads off of new crystals, but this a dedicated application and this is where it will always be.

I LOVE small parts!


Project on hold, waiting
Soldering Iron Micro Tip Replacement

While working on this project, I changed the tip of my new soldering iron for a larger size to solder the ground wire onto the crystal.  Unfortunately, the micro tip (1/64 inch wide) that I removed is was very fragile and does not like rough treatment - as I found out!

Without a spare micro soldering tip - this project is on hold until replacement (557-7566-100) arrives.

Six replacements tips are now on order - never again do I want to be without a spare.

I only had six more solder joints to make on this project!

My other soldering irons do not have small enough tips, as necessary for this task.

BTW: The photo above was taken through a Ring Magnifier Lamp with a older camera, it is less than expected of a real Macro Lens Camera, but it is OK for my purposes.

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