Prototype MPU Module Work in Progress

The prototype blank circuit boards for the MPU (Microprocessor Unit) arrived this week. I have been gathering parts for it and have everything cataloged according to item number in the bill of material. I have some parts mounted now.

MPU 002

The size is 3.8 x 2.8 inch. I put in about 6 hours on it today installing all the resistors, capacitors, diodes, transistor and some of the ICs. Building the first one is where you refine the assembly. Mainly the footprints might change so it will go together easier next time. One thing I did is change all of the 0402 components to 0805 size for future builds. It really pushes my limit to assemble 0402 components by hand. It looks like fly-crap, it is so small.

Next, I install the fine pitch ICs and connectors to complete the assembly. I am happy no major screw-ups have been detected. There is nothing more disappointing than scraping the work and doing it over.

This module is going to mount on the isolation wall between the RF Compartment and the Control Compartment. Imagine a sheet metal panel behind this board. In the RF Compartment will be the Amp Module, LP Filter, RF Path Module optional VHF/UHF Modules and the PSU.

In front of the MPU Module is the Display Module mounted on the back side of the front panel. I envision that the SMA connectors will poke through the isolation wall. Miniature Coax Cables will connect to these SMA connectors and route back to the RF PATH Module located on the inside Rear Panel.

The flat cables have a miniature head and can easily slip through slots as needed. They can be routed neatly around the periphery.

It is my project plan that the Display. PSU, Amp and MPU Modules are offered assembled and tested to improve the probability of builder completion.

I expect I will soon be cabling up the Modules on the bench and begin driver code writing and testing. Before I pump any RF through it, I need to get all the instrumentation alive and working.

If you are not following this blog, there is a FOLLOW button you can click. You will receive an email when I post to the blog. Please post the link for this blog every place interested builders might find it. We need volume to make the project low-cost. It is my hope that the blog will get more interesting as we progress.

File Attachment: mpu_hfspprov3 schematic.pdf (42 KB)

73 K5OOR –  Virgil

HF Projects




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