[BC] AM HD power levels

[RichardBJohnson at comcast.net]

Additionally, modulation transformers used in many
high power AM transmitters were easier to design
than 1 kW rigs because the operating impedance was
lower. This led to excellent AM fidelity up to the sixties
when the 250 W to 1 kW allocations opened up. After
the "no town without a radio station" fiasco began, AM
transmitters would usually not work above 7.5 kHz and
many of those designed by Parker Gates needed to
have their proofs fudged.

Of course the Doherty and Terman-Woodyard rigs
would work well up to 20 kHz. Eventually Fritz Bauer
made a 1 kW rig with good frequency response and
since the modulation transformer was in oil, it was
easy to inspect and copy. Fritz was an "old-time"
radioman who learned his craft at Western Electric.

He was the designer of the first 1kW kit transmitter.
Actually Paul Gregg did the "kit design" and wrote
the kit construction manual, but the electrical and
mechanical design was done by Fritz, 

--
Cheers,
Richard B. Johnson
Read about my book
http://www.LymanSchool.org


 -------------- Original message ----------------------
From: "Phil Alexander" <dynotherm at earthlink.net>
> While true, and while most vinyl began rolling off
> above 15 kHz, the performance of the RCA 44-BX was
> exceptionally good for a ribbon mic, and an old
> push-button GR audio oscillator would deliver any
> tone at 0.1% THD+noise from 20 Hz to 20 kHz.
> 
> ---------------------------------------------
> Phil Alexander, CSRE, AMD
> Broadcast Engineering Services and Technology 
> (a Div. of Advanced Parts Corporation) 
> Ph. (317) 335-2065   FAX (317) 335-9037
> 
> 
> On 1 Sep 2008 at 14:58, Robert Orban wrote:
>  
> > The great Dr. Harry Olson of RCA Labs always maintained that 15 kHz 
> > was good enough for high fidelity reproduction.