For years, I've enjoyed reading the blogs of other radio and electronic hobbiests and following the blogger's progress as he (she) converts an idea, first into a seemingly random pile of parts, and then into some sort of useful or superfluous (but nontheless fascinating) device.
This got me to thinking: I make some pretty cool and weird stuff, and I'm semi-literate, maybe someone might be interested in following along on some of my techno-adventures? So, here we are!
To introduce myself: I'm Steve Murphy, N8NM. I've been a licensed amateur for over 30 years, extra class for 28 of those, but my fascination with making things out of junk started long before I was ever granted any sort of license, other than, perhaps, a library card. As far back as I can remember, I was lugging home the carcasses of discarded TVs and radios, where I'd carefully dismantle them and sort and catalog all of the various bits. God, I wish I were as organized today as I was at six or seven!
Since then, I'd built numerous small "homebrew" accessories, some of which worked as desired, and quite a few kits (most of which worked as designed), but it wasn't until about 20 years ago when I jumped in with both feet, designing and building my first homebrew receiver. It was a relatively simple affair: 20 meter band only, using a FET VFO, MC1350P IF amplifiers, SBL-1 Mixer and product detector and LM-380 audio. It worked well enough to receive signals and I even used it for a few QSOs, but the VFO drifted horribly.
Career and changes kept my homebrewing on the back burner for the next several years, when I again decided to jump in and build a "modern" version of the 6AG7/6L6 MOPA transmitter - covering 80-10m using Xtal or VFO control and with a regulations-compliant PI-L filter on the output. This one worked much better, and I still occasionally use it today..
Then, a couple of years ago, I came across Ashhar Farhan's discussion of his new Minima transceiver. I was already aware of his famous BITX rigs, but the Minima intrigued me because it was an "All band" transceiver. So, I started analyzing Farhan's design, changing things here and there, mainly just because I could, and about six months later had my version of an 80-10m SSB/CW transceiver with general coverage receiver. Though still unfinished, this is my current "main" rig.
This little rig uses two bilateral, termination sensitive amplifier blocks for the IF stages, homebrew diode-ring mixers for the mixer and product detector, and an LM380 driven by a 2N3904 for the audio. Mic amp is a pair of J310s. VFO and BFO are provided by the wonderful little Si5351, which is controlled by an arduino Nano, and the RF PA is currently a switching MOSFET, providing about 15 W on 80 down to about 2 W on 10. Made hundreds of QSOs on this rig - having so much fun that I haven't been able to bring myself to tear it down for paint!
Another rig that I've been working on (and is setting on the back-burner at present) is my "Thermatron" receiver. This is a general coverage SW receiver that uses tubes in the signal path, but is controlled by an Arduino Uno and uses another Si5351 for frequency/bfo.
It's really a cool little rig - it works, but needs a lot of refinement. I plan on finishing this one up over the winter months.
So, what's in the works now? Well, a couple of things! About a month ago, after some email exchanges with Pete Juliano, N6QW, I got the bug to build a 60m rig. Since, in all of my prior efforts, I've started by having a chassis footprint and panel layout in mind, which never leaves quite enough room for all of the circuitry, I decided to build this one on a simple chunk of scrap board and figure out how to package it afterwards. On seeing pics, Pete bestowed a rather brilliant name apon it: The Planker!
So, here's the planker in it's current state - AF/IF/Mixer/BFO and low-level transmit stages are operational, next step is to complete the PA and band-pass filters. Since 60m is channelized, I opted to use a single 7 segment LED (left over from an abandoned project) to indicate channels 1 - 5, with 6 being WWV at 5.000 MHz. The receiver works great, and the low-level transmit signal sounds good and the IF bandwidth is within the FCC requirements, so I just have to give it some suitable "snot" to drive the antenna. Looking forwared to that - 60m is the only HF band where I've never made a single QSO!
Meanwhile, I have several antique radio restorations in the works, including an Atwater Kent 20C, ERLA "Sky Rover" console, and a recently acquired NC-109 that - hopefully - won't require much more than a simple "recap". Fortunately, I have enough bench space to support going back and forth between all of these active projects, which suits my short attention span perfectly.
So - this is me and what I do... From here forward, I'm going to share some of my fun with you, in much the same disorganized and unorthodox manner that I work in. One day, I may document progress on some cool HB transceiver, then the next, write about replacing the mica wafer capacitors in the IF cans of a 50s GE or Zenith.
Sounds like fun? If so, please feel free to check back often!
73 - Steve N8NM