Yes, that's an interesting tube line up. I'm kinda leaning that way. That's
a great way to provide voltage for both the final's screen and driver's
plates. One regulated supply - I like it. Richard Measure's FET reg supply
design wud work well there. Looks like they are drawing some grid current
on the final. I wonder what the final IMD figure is on that lash up?
Colin suggested the 6550 tube as a low level driver. It's got nice, clean
curves and they are avavilable cheap on the web. So I can eliminate the
6146 unless I do the series 4CX-350's.
Gary / K4FMX, I don't have access to the old 1967 QST issues, but maybe
there is a accessible spot on the web?
> Hi Tom,
> I put diagrams of the Harris linear and the Racal widebanddriver
> on the following website:
> By the way,
> the TA1800 also uses 10db of negative feedback, but just to the driver
> stage, not to the pre-driver.
> All stages run class AB1, except the wideband-pre-amp which is class A.
> 25mW -> wideband pre-amp 250mW -> pre-driver 4CX350A 2.25W -> driver
> 2x4CX350A 113W -> 4CX10000D 10KW.
> The 4CX350A get their 1500V anode voltage from the screen-supply of the
> 4CX10K, clever!
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