KC9KEP - A work in progress



  Homebrew Radio Projects - Knight Space Spanner


Before building my first Space Spanner many years ago, the fruits of my radio fabrication career were represented by a of couple crystal radios with hand-wound shellacked coils, orange-crate-wood bases, and coat-hanger wire tuning-coil wipers. 

I had probably received the Space Spanner kit as a birthday present when I was around 8 or 9 years old. 

What an experience, being exposed to this new technology for the first time! 

Featured in the kit were foldout illustrations of components that were transformed into Alfred Morgan-esque cartoon-like gray-scale line drawings.  Also included were solder “lugs”, terminal strips, 6-32 hardware and many types of hardware and components that I’d never seen or even heard of before!  (What an uncharted territory! .. could I pull this off?) 

Ahh .. Nothing beats the sophisticated order of fresh phenolic tube sockets, new proxylin (what’s that?), wood and glue!  Neat colors too .. large green square mica capacitor & yellow-brown filter cap, blue & red colored wires, jet-black shiny control knobs with crisp white indicator lines. 

My tools then were crude at best .. a honking Weller soldering gun, lineman’s pliers, maybe a needle nose pliers, and I don’t even recall what I had used for a wire stripper/cutter. 

I remember such events as soldering a small reddish-brown ceramic cap to a tube socket, & watching the paraffin break into a excited dancing boil .. Whoa! .. Cool! .. Hope I didn’t wreck anything! 

Back in class in grade school, I’d long for 3:15 pm so that I could race back home to resume work on the project that had mentally eclipsed any lesson that the teacher could present.  I felt so validated & invigorated to be engaged in this potent technical scientific arena.  Frequent unsuccessful attempts were made to satisfy my yearning by trying to recall the triode detector circuits and sketch them on my wood desktop with pencil.  (Luckily, the teacher never caught me.) 

And, I remember it being a hot summer while building the project on my Ma’s oak kitchen table. 

Unfortunately, when first powered on, the radio’s only hint of life was a nasty and persistent 60-cycle (it was called “cycles” then) hum. 

My friends could only offer mystified condolences.  I was trail blazing here.  And, I owned no trouble shooting equipment then, not even a VOM. 

Fortunately, my Dad (who I've suspected of living an electronics career thru me) took the radio to a repair shop & got ‘er going. 

Funny, I remember more about the fabricating the radio than actually using it! 

I suppose that I finally got tired of the Space Spanner when we purchased a Heathkit GR-91 and the Spanner went the way of all winds .. 

So, here it is, about a half century later and I came across one of my old books that I had received as a Christmas present in 1962 (Dang, my folks was good to me!) 

“Electronics Made Easy” by Stern.  And, as luck would have it, one of the featured projects was the ubiquitous Space Spanner. 

I had already built a couple regenerative receivers that past year (Alfred Morgan’s one-tuber and the 1930’s Doerle TwinPlex), so how could I not build the Space Spanner again? 

(I have been watching eBay to purchase one of these old receivers, but dang .. they’re asking a lot of money for a set that cost $19.95 new!) 

And, I’ve got my Gingery Universal Coil winder and my Lindsay Grid Dip Meter now .. precisely the tools that could conceivably provide me with the ability to fabricate the only “missing” components, i.e. the tuning/tickler coils. 

Armed with much more experience (and finance) and some sheet metal tools at my disposal, here it is .. the 2006 Space Spanner.  It’s coming up on its 50th birthday!

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