[Hallicrafters] RTMA Dummy Antenna needed for alignment?

[Roy Morgan]

On Apr 28, 2008, at 11:10 PM, Roger D Johnson wrote:

> The whole idea of the dummy antenna was to align the input
> of the receiver with the "standard" 50 to 100 ft wire
> antenna most listeners used in the old days that generally  
> gave .... a compromise adjustment

There was another reason, also:

At the time the "Standard Dummy Antenna" was defined, there were few  
standards.  Manufacturers could claim most anything about the  
performance of their receivers, and did. Fair comparisons between  
receivers could not be made.  In addition, the military was  
increasingly specifying the performance of receivers and found there  
was no common method of setting up test conditions for sensitivity  
acceptance tests.

I think it was in the late 1930's (perhaps 1938) that the predecessor  
to the RTMA published the spec.  There was an article in a national  
magazine (Perhaps the IEEE journal) that seems to have introduced the  
thing, and likely has more information about the thinking at the time.

Roy


  Roy Morgan
k1lky at earthlink.net
Lovettsville, VA 20180