Armstrong Days at Infoage  
Previously scheduled for 26 - 27 January 2013
POSTPONED due to lack of power at the site.
Stay tuned for further information.

2012 marks the 100th anniversary of the development of the regenerative radio circuit by Edwin Howard Armstrong an electrical engineering student at Colombia University.  This invention not only greatly improved the performance of radio receivers, but would also become the basis for modern radio transmitters, making voice transmission, and radio as we know it, a reality.

The New Jersey Antique Radio Club’s Radio Technology Museum will host an observance of the occasion at the InfoAge Science History Learning Center and Museum in Wall Township, NJ on January 26th and 27th, 2013  from 1 to 5 PM.  There will be a display and demonstration of a wide range of vintage regenerative radio receivers with a formal presentation at 2 PM.  The other InfoAge museums will be open as well.  Admission is free.  A five-dollar donation to InfoAge is suggested.

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Working receivers on display will include a mock-up of Armstrong’s original circuit receiving a simulated spark radio-telegraph transmission, a WWI era naval receiver, early regenerative broadcast receivers, more sophisticated “regens” that dominated amateur radio and the early phases of the short-wave-broadcast craze in the 1920’s and 30’s, and a naval RAL receiver  that served throughout WWII.

Armstrong is arguably the greatest radio inventor since Marconi.  His regenerative receiver was followed in 1918 by the superheterodyne, the basis for nearly all modern radio receivers. During the 1930’s Armstrong developed high-fidelity FM broadcasting.  His FM technologies also found their way into two-way mobile radio, and radar during WWII.

"Audion" Control Box OK, we don't know what the original regenerativer receiver looked like when Armstrong made the initiial discovery, but we're going to guess.
In Armstrong's own words:

"All the old timers remember CC, later known as MCC and WCC, the Marconi press station at Wellfleet, Mass.  This station was the one-hundred percent reliable testing standby of all experimenters, and on MCC the first tests were made.  A standard audion detector system was set up and tuned in, and a tuning inductance introduced into the plate circuit of the audion.  Then various things began to happen.  As the plate inductance was increased, the signals were boosted in strength
to an intensity unbelievable for those days, the more inductance the louder the signal, until suddenly the characteristic tone of MCC -- the tone which any of the old timers, if they heard it on Judgment Morn, would recognize instantly -- disappeared, and in its place was a loud hissing tone, undeniably the same station, but recognizable only by the characteristic swing and the messages transmitted.  A slight reduction of the plate inductance and the old tone was back again, -- and then the placing of the hand near a tuning condenser and the hissing tone reappeared.  It required no particular mental effort to realize that here was a fundamentally new
phenomenon, as obscure as the principle of the operation of the audion itself, but which opened up an entirely new field of practical operation."

With our simulated MCC, you'll be able to hear what Howard heard on that important night in 1912.

Here are some of the other radios we expect to have online for you listening pleasure:
IP-501 Receiver The IP-501 was the U.S. Navy's first receiver with the vacuum tube inside the cabinet.  This regenerative design was the work of  Alan Hazeltine.
In the early 1920's, John Reinartz, of QST, showed the amateur radio world how to build simple and effective regenerative receivers for amateur use.  Large number were built by the homebrew crowd.  With a little luck will have this one on the air. Reinartz receiver
National SW-45 In the late 1920's National Radio Company introduced a line of TRF-Autodynes (a regenerative detector proceeded by a tuned RF amplifier).  Here ithe "big-gun" SW-45, a derivative of the SW-5 with push-pull  type 45 triodes for "high-fidelity output.  Such receivers helped start the short-wave-listening craze.
More homebrew.  George Grammar's 1933 QST article "Rationalizing the Autodyne" supurred the construction of a lot of regenerative receivers that largely outperformed  all but the best superheterodynes of the day. Rationalized Autodyne
Navy RAL receiver The U.S. Navy RAL designed by RCA in the mid-1930's is arguably the best short-wave regen ever built.  It sports two tuned-RF stages, two tuned audio filters and AVC provided by an audio limiter.  They served on small ships and submarines throughout WWII.
The regenerative receiver lived on.  Many of us got our start in electronics by building kits like this in the 1950's ans '60's.




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