Tuesday, March 24, 2020

Dean KK4DAS's "Furlough 40" SSB Rig


Introducing the "Furlough 40" scratch-built SSB rig:





Greetings!

I know this is beginning in the middle and the best time to plant a tree was 10 years ago, but here goes...

I'm Dean, KK4DAS.  I 've been a licensed ham for about a year and a half, although amateur radio has been part of my life forever.  My Dad, Vic W6MYE/SK was a ham for most of his adult life - at least 60 years (my age now) and it is one of the ways  I will always remember him.  My brother Chris, W6CS has been a ham fore many years and I was very happy that he and I could share the hobby with Dad.  I'm sure I'll write more about that over time, but today I have some exciting news to share.


Inspired by Bill Meara, N2CQR and Pete Juliano, N6QW, the Wizard of Newbury Park, and the Soldersmoke Podcast, for the last eight or nine months I have been on a homebrew journey that has led to the completion of the receiver side of a 100% scratch-built 40 Meter SSB Transceiver.  I've been working on it since January and thinking about it even longer.  The design I selected, after advice from Bill and Pete, was Pete's SimpleSSB Transceiver.  It is a wonderfully elegant design that uses 10 common transistors total - which one of the reasons Pete calls it "simple".  It was far from simple for me -  I should tell you that the most complicated electronic project I had built up to that time was a Michigan Mighty Mite, 7 component, crystal controlled, CW transmitter, which I actually got on the air and Bill was kind enough to blog about. I'll talk more about that project in a later post.  Although I have a technical background, it is largely in computer software and networking. I've been building and delivering complex software systems all of my adult life.  But electrical engineering was not my thing.  W6CS is an electrical engineer, but I am strictly a software guy. Until now...

I am proud to unveil the "Furlough 40" SSB rig, christened in honor of the fact that the current crisis afforded me some stay-at-home time to get the rig finished.



My original goal was to be ready by June, but circumstances have allowed me accelerate that schedule considerably. I've been documenting the project along the way and after today I will back up and tell you a little about the journey.

For the more technically minded the rig is a 40 Metter SSB phone transceiver.  The rig is controlled by an Arduino Nano microcontroller driving an SI 5351 clock generator for the LO and the BFO.  The IF is at 9 MHz utilizing a crystal filter purchased from the GQRP Club.  The IF is bi-directional as is the RF amplifier with relays switching between transmit and receive.  It uses two ADE-1 double balanced mixers and the bi-directional amplifiers are Pete's implementation of the Plessy amplifier design from "Experimental Methods in RF Design."  I'm building the rig in modules, per the sage advice of Bill and Pete, and testing as I go. Each working module can be used the test the next module.  The construction style is nearly 100% Manhattan style - save for the Aarduino and SI-5351.

Thanks to Bill for all of his support and thanks, especially, to Pasta Pete Juliano, master Italian Chef and the true wizard of Newbury Park.  Pete continues to patiently answer my questions and guide me through testing each module as it was completed, and gently providing encouraging instruction when I veered too far left or right from plan - even to the point of sending me a hand-drawn sketch of the bottom view of a N2219A transistor so I would know, always, how to wire it in correctly in the future.

More later, but for now - best 73s from Great Falls, VA

Dean
KK4DAS


3 comments:

  1. Absolutely terrific progress!! Beautiful construction and you should indeed be proud of what you have done. Soon it will be on the air. Bravo and Kudos my friend. Can't wait to hear about your very 1st QSO with the Furlough Forty. I assume we will soon hear about The Time Off Twenty?

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  2. How about a Pandemic Panadapter,or, pandemicxapter? Hahaha. Nice work. You are creating minor miracles out of bits of wire, code and little thingies.

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  3. I love the heat sink on the RFamp. Done in true ham sprite. 👍
    Jim

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