[Heathkit] Suggestion for legal limit AM amp (was Heath Warrior as an AM amplifier)

[Richard Knoppow]

----- Original Message ----- 
From: "Robert Nickels" <ranickel at comcast.net>
To: <heathkit at mailman.qth.net>
Sent: Tuesday, January 17, 2012 9:36 AM
Subject: Re: [Heathkit] Suggestion for legal limit AM amp 
(was Heath Warrior as an AM amplifier)


> On 1/17/2012 11:04 AM, Carl wrote:
>> The T Bolt is a bit weak in the PS for extended old 
>> buzzard transmissions
>> from what Ive heard on the air and read elsewhere.
> Carl,
>
> Based on your amplifier experience, wonder what you think 
> about driving
> linears with controlled-carrier AM exciters?   I've not 
> tried it myself
> but hear guys on the air all the time running rigs like 
> DX-60s,
> FT-101-series, and even some riceboxes that seem to work 
> quite well.
> The lower resting carrier level would seem to be a way of 
> getting some
> good power out of the lower-rated linear amplifiers like 
> the Warrior.
>
> All I know is that the audio quality can be very good, 
> although it is
> important to set the proper carrier and modulation levels. 
> Just
> listening to these stations on AM nets, I can't tell the 
> difference vs.
> high-level modulated stations.   I'm guessing that a PEP 
> wattmeter would
> be the best way to set up the combination to  operate 
> within legal limits.
>
> 73, Bob W9RAN
>
     I think the main advantage of a controlled carrier AM 
rig is that it _is_ compatible with linear amplifiers. This 
is because the _average_ level is low since it follows the 
modulation. Essentially, the rig is modulated nearly 100% 
all the time except for the residual carrier. The only 
problem I've observed with it is that the AVC in normal AM 
receivers (fast AVC) tends to follow the carrier and pumps 
unpleasantly. For an SSB receiver with slow AVC this is not 
so much of a problem. For older AM receivers using manual 
gain may result in better sound.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com