[Boatanchors] Screen Modulated AM

[mac]

You had better be doing your initial tune up of both the DX-60 and  
linear with the DX-60 in the CW mode.

Gary has it completely right.  You would do well to go back and study  
his posts carefully.

Dennis D.  W7QHO
Glendale, CA

*********************

On Aug 12, 2009, at 12:43 PM, rbethman wrote:

> It does not take more than a couple of simple paragraphs to explain  
> this
> mode of AM operation.
>
> It sure as heck does not require tuning to 400W then dialing down to
> 100W and control the screen voltage in a multi-page explanation.
>
> This is why the 2X = 3dB and all its discussion got over blown.
>
> Here is an example, again, of simply doing it.  The readings of  
> specific
> number of final mA grid current and the like are in the radio MANUAL!
> That is why they print them.
>
>    To use a screen modulated radio with a linear amplifier, I.E., a  
> DX-60
>    into an Amp Supply LK-500ZB:
>
>    Tune DX-60 with the amp on standby.  DX-60 will get about 25W  
> out.  Then, turning the DX-60 off of Tx mode, turn amp to ON from  
> standby.  Put DX-60 to Tx, and rapidly, tune the Amp for max  
> output.  Observe
>    output, (Power meter), to see what carrier level you have with  
> the carrier ONLY from DX-60.  Ensure you have the "headroom" in the  
> amp.
>
>    A DX-60 will do around 25W itself on AM for a carrier.  Fed into  
> Amp Supply LK-500ZB, the carrier when tuned for max will be about  
> 300 to 350W carrier.
>
>    Now the control for modulation is the audio level adjustment.   
> The DX-60 is on the chassis behind the panel.  The audio chain is  
> what controls the screen levels.
>
> That's it in a nutshell!
>
> Bob - N0DGN
>
>
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