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Saturday, May 31, 2014

Harv's Minima

Good Evening Bill & fellow Solder-smoke friends,
Well, I’m following the pack. I began gathering items for the Minima Transceiver back in March 14. There had been a good bit of strong back-N-forth discussions on the Minima Blog about what works and what doesn’t work. Some circuit refinements had been agreed upon while other were left to individual preferences. So, I decided to just be silent an learn from the experts. As a result, I did several months of observing before I took the plunge. While my efforts are not nearly as aggressive as others, I decided to forge a much slower path to success.
In my own quirky way of doing things, I kitted each module, measured all the parts statically, laid out the components, and finally built & tested each assembly before going to the next.
As a result, the learning’s were great and the performance of each section equal or better than my expectations.
I went the Manhattan Style this time but,  I have purchased several sets of Minima PCBs to use in the future. As I see it, there is a lot more solder melting ahead.
Bill, building radios is NOT DEAD yet. That desire to get back to the golden days of home-brewing still lives on.
At the end of the Memorial Weekend, this is my current Minima progress…
·         Construction of all 3 Audio Stages now complete (see photos)
·         The Microphone Pre-Amp is now awaiting voice testing
·         Audio Amplifier and Final Amplifier have been tested together
·         The results of audio testing has been superb for all stages thus far
·         3 complete sets of Micro Relays have been order and I’m now awaiting their arrival
·         24 – various ferrite and powered iron cores arrived several weeks ago, these are the heart of the front-end RX/TX stages
·         100 - 20 Mhz. crystals have arrived and await characterization
·         25 - 8” Male to Male SMA Cables have arrived this weekend, will need to order 15 – 4” Male to Male SMA Cable Assemblies next
·         5 – 12” X 15” Copper Clad Boards have arrived this weekend
·         25 –J310 N-channel J RF Power FETs were ordered and arrived this weekend, these are used in the Mixer Stage
Final Audio Stage
Audio Amplifier Stage
Microphone Pre-Amplifier Stage (see microphone connector mounted at rear)
I’m ready to begin kitting the Side Tone Oscillator and RX/TX Relay Stages.
The largest and most intense modules are yet to be tackled.
The Bi-Directional Amplifier has 34 parts alone.  So far I have installed over 40 parts in the three modules I’ve completed…
I realize it is just a start but, I’m motivated to see this one project through to completion.
73’s & Happy Soldering
Harv -=WA3EIB=-
Albuquerque, NM.

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  1. Mind giving some suggestions on how to get started. I'm finding the schematic a little overwhelming and would like to build, test and most importantly understand each block before moving on. Any suggestions would be greatly appreciated.

  2. Where did you get your bag of 100 crystals? 73's, David

  3. Unknown,

    There is an incomplete build guide being developed by Mac Cody, AE5PH. The guide is based on a set of PCBs you'd have to have printed yourself, but the guide could be useful for anyone using ugly/Manhattan/perfboard as well since it walks you through building each section and testing it.

    I think these are the latest PCBs:

    Good luck!
    Kevin, K1AHB

  4. Sorry, see this page for PCB files that can be uploaded to a printer:



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