1206 Attenuator PCB

wip_d2

This page is work in progress and may be updated frequently (last update : 2020-03-18 19:37 UTC). 

This is a updated design of the previous 1206 Attenuator PCB (aka a failure in PCB design).

Introduction

As a hamradio homebrewer I often use attenuators to get a signal down a few dB and sometimes I want very strange values. For those cases I designed these 1206 PI network Attenuator PCB's with SMA Edge connectors using KiCad. 

1206_att_sch

Based on this schematic I designed the PCB shown below. I added area's without solder mask around the edges to a low adding some shielding over the PCB (not visible in image below).

1206_att_pcbv2

The cool thing from KiCad is that is also has a 3D viewer. Unfortunately the SMA Edge connectors aren't in the 3D shape library.

1206_att_3dv2

For the attenuation values I used this calculator : https://chemandy.com/calculators/matching-pi-attenuator-calculator.htm and  the image below contains a list of "standard" PI network attenuation resistor values. 

1206_att_tbl

It's nice to have it all in theory but we want the real thing. So I ordered small batch of pototype PCB's to see if I didn't mess up this simple design. 

 

To be continued.  

Where to buy 

I ordered a small batch of PCBs and build a few prototypes. And when they work out, I will publish the project on this site and on OSHPark so you can order 3 PCB's for just $2.98 at OSH Park (that's including shipping!!!).  

The design will be publicly available so you order your own PCB's but licensed it Attribution-NonCommercial-NoDerivs 3.0 Unported (CC BY-NC-ND 3.0).
Meaning : 

  • Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • NonCommercial — You may not use the material for commercial purposes.
  • NoDerivatives — If you remix, transform, or build upon the material, you may not distribute the modified material.

It's not to be childish but it now happened a few times that a 3D design I made was sold by other people just because is was "Open source, so I can do anything I want with it" without any credits or even a token of appreciation

When you like the design and PCB's. a small fee as a token of appreciation / commission to support my work is very appreciated (see : Support & Tip Jar).

 


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