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Chuck<br>
<br>
I did some research, and looks like you're right.<br>
<br>
With suppressed (reduced) carrier DSB the carrier level stays the
same with modulation. Unbalancing the <br>
balanced modulator in a side band scheme doesn't imply the carrier
goes up with the modulation.<br>
<br>
With controlled carrier AM the carrier rises with the modulation.
But unless well designed, not linearly. <br>
<br>
Still, I think I was right about saying both can be demodulated with
an envelope (AM) detector. However, I've read that if the AM
receiver uses AGC, carrier controlled AM usually sounds bad<br>
<br>
Tnx<br>
<br>
Chris<br>
<br>
<br>
<div class="moz-cite-prefix">On 5/20/2018 6:14 AM, Chuck Moore
wrote:<br>
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<blockquote
cite="mid:1637db004b9-c8e-7a8f@webjas-vaa119.srv.aolmail.net"
type="cite"><font size="2" color="black" face="arial">If <font
size="2">memory serves me correct suppressed carrier had a <br>
fixed level reduced carrier. With controlled carrier <br>
the carrier amplitude varied with the sideband<br>
amplitude. Am I confusing the two?<br>
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<div style="clear:both">Chuck Moore<br>
<a class="moz-txt-link-abbreviated" href="mailto:wcmoore@verizon.net">wcmoore@verizon.net</a><br>
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<div
style="font-family:arial,helvetica;font-size:10pt;color:black">-----Original
Message-----<br>
From: ChrisIwata via Heath <a class="moz-txt-link-rfc2396E" href="mailto:heath@puck.nether.net"><heath@puck.nether.net></a><br>
To: heath <a class="moz-txt-link-rfc2396E" href="mailto:heath@puck.nether.net"><heath@puck.nether.net></a><br>
Sent: Sun, May 20, 2018 9:04 am<br>
Subject: Re: [Heath] DSB...<br>
<br>
<br>
I don't mean zero carrier DSB, I mean suppressed carrier. In
modern <br>
day this amounts to unbalancing the balanced DSB modulator, so
that some <br>
carrier is there even in the absence of modulation.<br>
<br>
I'm not talking about the implementation, I'm talking about
the signal.<br>
<br>
Yup, I agree controlled carrier AM is much easier to
implement. Both on <br>
the transmitting end and the receiving end, compared to DSB.<br>
<br>
Seems to me the signal generated by controlled carrier AM is
the same as <br>
suppressed carrier DSB? Neither one has zero carrier with no <br>
modulation, and the carrier increases with modulation. I don't
know, <br>
maybe the controlled carrier signal is not a linear
representation of <br>
the modulation as is the case with suppressed DSB? That is, if
you <br>
speak twice as loud, the controlled carrier might not go up
twice as much?<br>
<br>
The one big feature of this signal is it can be detected with
a simple <br>
envelope (AM) detector, just like plate modulated AM<br>
<br>
When you think about it, aside from CW, modern ham radio
communication <br>
has become very complex. I guess this is why home-brewing is
becoming a <br>
lost art.<br>
<br>
Chris, KL7DM<br>
<br>
<br>
On 5/19/2018 4:34 PM, Kenneth G. Gordon wrote:<br>
> OK. I did some research: generating a DSB signal requires
a balanced modulator<br>
> somewhere in the system.<br>
><br>
> In one case I remember, the two 1625s in an "ARC-5"
transmitter were used as a<br>
> direct-to-antenna DSB transmitter.<br>
><br>
> The screens were fed push-pull audio, while the plates
were parallel-connected. As I<br>
> remember it, an oscilloscope was required to get it
adjusted properly.<br>
><br>
> DSB is far more complex than the simple
controlled-carrier systems in our simple<br>
> transmitters.<br>
><br>
> If anyone here is interested, here is a link to the
"Double-Sideband Junior" from GE Ham<br>
> News of March-April 1958.<br>
><br>
> <a moz-do-not-send="true"
href="http://n4trb.com/AmateurRadio/GE_HamNews/issues/GE%20Ham%20News%20Vol%2013"
target="_blank">http://n4trb.com/AmateurRadio/GE_HamNews/issues/GE%20Ham%20News%20Vol%2013</a><br>
> %20No%202.pdf<br>
><br>
> Ken W7EKB<br>
><br>
> ---<br>
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> <a moz-do-not-send="true"
href="https://www.avast.com/antivirus" target="_blank">https://www.avast.com/antivirus</a><br>
><br>
> _______________________________________________<br>
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