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Author Topic: Flea power and high power from April 1939  (Read 2479 times)
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WQ9E
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« on: October 22, 2012, 07:08:04 PM »

Two transmitters from the April 1939 issue of Radio News.  There are complete construction details for the low power rig; the high power rig doesn't look like any homebrew rig I have ever run across Smiley

* 160 flea.pdf (598.05 KB - downloaded 247 times.)
* Model 1 KW Rig.pdf (2279.22 KB - downloaded 260 times.)
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Rodger WQ9E
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« Reply #1 on: October 22, 2012, 09:11:53 PM »

Looks like a 1939 version of the single band finals from 20 years later.  Of course, power was harder to come by in 1939.  Not like being able to get a KW with a pair of 813's with very little drive power.  Nice construction.  Fine attention to detail.  Wish I had the time and patience to do something like that.
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73,  Mitch

Since 1958. There still is nothing like tubes to keep your coffee warm in the shack.

Vulcan Theory of Troubleshooting:  Once you have eliminated the impossible, whatever remains, however improbable, must be the truth.
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Patrick J. / KD5OEI
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« Reply #2 on: October 23, 2012, 10:08:09 PM »

Nice electronic keying arrangement on the KW unit described. KY21 tubes rectify and control the HV directly, very excellent! He says there is more in future articles. Maybe the other two TX will also have their special features pointed out.
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Radio Candelstein - Flagship Station of the NRK Radio Network.
WQ9E
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« Reply #3 on: October 23, 2012, 10:23:26 PM »

I will keep an eye out for any additional information/articles about those transmitters in the newer issues.  Right now I have moved back to the 1930 era Smiley 

Glenn H. Browning and James Millen have an interesting article in August 1930 with the title, "Satisfying the Demands for Sensitivity, Selectivity, and Quality in the Design of a Modern R.F. Tuner".  The title length reminds me of some of the Ph.D. dissertations I have read and all it is missing is the requisite colon and sub-title.  It looks like this article provides the background for the SW-5 "Thrill Box".

In February of 1931 we have "Dr. Robinson Explains the Stenode Radiostat" which must be one of the earliest examples of a crystal filter used in a receiver.  It has a 100 Khz. IF with the crystal installed in the final IF stage.

I will try to scan these later this week.
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Rodger WQ9E
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