Thanks for the prehistoric trivia lesson (-;
I was referring to vacuum tube technology where AM was at least
understandable to some degree of quality.
Carl
KM1H
----- Original Message -----
From: "Fuqua, Bill L" <wlfuqu00@uky.edu>
To: "Carl" <km1h@jeremy.mv.com>; "Joe Subich, W4TV" <lists@subich.com>;
<amps@contesting.com>
Sent: Friday, September 13, 2013 1:05 PM
Subject: RE: [Amps] S/S Amp's
What became known as Exalted AM was really a technique that was used
back in the later spark era days once they developed nearly CW sources.
In fact that is where the term local oscillator and BFO came from. They
discovered
if an oscillator near the frequency you were receiving was coupling into
the diode detector,
you not only had a beat tone but the sensitivity increased over 100 times
sometimes up to
500 times. This was because the detector was being over driven to
saturation during have
of the oscillator cycle and was behaving as a RF switch. It was performing
more as a
product detector rather than a square law detector. In fact Marconi
Patented the first
balanced product detector in 1916. It used a buzzer and high Q tank
circuit for the BFO or
Local Oscillator. Local oscillator means an oscillator near the detector.
By the way, another interesting fact, unrelated, Hertz discovered the
photo electric effect
before 1900.
73
Bill wa4lav
________________________________________
From: Carl [km1h@jeremy.mv.com]
Sent: Thursday, September 12, 2013 9:49 PM
To: Fuqua, Bill L; Joe Subich, W4TV; amps@contesting.com
Subject: Re: [Amps] S/S Amp's
By using the Exalted AM method that goes back 70 years you dont need a
fancy
radio.
Modify the BFO for variable injection level and connect to the last IF
thereby maintaining AGC. Its almost as good as a sync detector for
selective
fading and its easier to follow a slightly drifting carrier.
Carl
KM1H
----- Original Message -----
From: "Fuqua, Bill L" <wlfuqu00@uky.edu>
To: "Joe Subich, W4TV" <lists@subich.com>; <amps@contesting.com>
Sent: Thursday, September 12, 2013 4:14 PM
Subject: Re: [Amps] S/S Amp's
Most hams today can't tune SSB clearly.
AM always sounds right. Perhaps we should have SSB reduced carrier rather
than
suppressed carrier. Another point, DSB occupies same bandwidth as AM.
You could receive DSB or AM by detecting, using bfo and SSB filter,
only
one sideband but with the loss
of 3dB signal to noise ratio compared to receiving it with synchronous
detector.
73
Bill wa4lav
________________________________________
From: Amps [amps-bounces@contesting.com] on behalf of Joe Subich, W4TV
[lists@subich.com]
Sent: Thursday, September 12, 2013 2:29 PM
To: amps@contesting.com
Subject: Re: [Amps] S/S Amp's
For the same reason they spam other bands with ESSB, IM products,
keyclicks, splatter and/or full carrier AM - because they can and
the rules against stupidity, and bad operating practices either do
not exist or are not enforced.
73,
... Joe, W4TV
On 9/12/2013 12:14 PM, qrv@kd4e.com wrote:
Why are Hams still rf-spamming 160 & 80m with AM carriers
when a DSB suppressed-carrier signal is just as good, uses
less power, and may be sync-detected to remove flutter, etc?
I know, I know, ... never mind ... sigh.
Jim said;
"It sure would be nice to just rectify the 120vac from the wall plug,
with
or without any isolation xfmr"
It's already in production.
Not quite what you're after but... <http://www.k7dyy.com/>
http://www.k7dyy.com/
David G4ZOW
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