Wednesday, November 14, 2018

W7ZOI: Direct Conversion Receivers -- Some Amateur Radio History


http://w7zoi.net/dcrx68.pdf

Farhan and Pete WB9FLW alerted me to this wonderful article by Wes Hayward, W7ZOI.  I guess my interest in DC receivers must have been noticed by the Google algorithm because I am bombarded by ads extolling the virtues of "Zero IF."   Hey Google -- I'm already a believer!  I was converted by W7ZOI's 1968 article in QST. And my belief in the technique has been greatly reinforced by his November 2018 50th anniversary article. 

There is so much good stuff in Wes's look-back piece.  The travails of trying to write for QST are presented very well.   And we learn that none-other-than Doug DeMaw himself is responsible for the use of the word "presence" in describing amateur radio audio.  

This article has inspired me to take a new look at the DC receiver I built last winter.  Mine needs some work. I think it is kind of deaf.   It could probably benefit from a diode ring  detector.   But it already has presence.   

http://w7zoi.net/dcrx68.pdf

Thanks Wes.  And thanks to Farhan and Pete for the heads up. 

2 comments:

  1. This was a stroll down memory lane. I was just getting back into ham radio, getting married and starting a medical practice so I was more of am observer, not ready to start building QRP rigs. BUT when Heath came out with the HW7 and then later TenTec came out with the Argonaut series I was hooked. Later Doug DeMaw moved just south of me at Luther, MI to retire and he lectured at the local radio clubs until his passing. What warm fuzzy memories. Thank you Pete, Bill and Wes.

    On the same thought I sent your notes to a new ham for some background on building and receivers and told him that Wes’s name is still spoken with reverence in my shack and that Doug was the Godfather of QRP.

    DAVE k8WPE

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  2. And in 1968 while Wes was experimenting with balanced mixers, the electronic music crowd were doing the same thing to generate novel beat notes. But they called them ring modulators. http://electro-music.com/forum/phpbb-files/hughdaviesringmod_140.pdf

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