Gee, that feed forward correction method sounds like something that would be
ideal for the FT-1000D. As you said, it could be later moved from rig to rig
So far all I've seen on the web are ivory tower block diagrams, etc. Is
there a tested circuit available somewhere to build up or a commercial
surplus unit? Even something that has suggested chip choices with a circuit
I could then modify to my use would help.
For this particular project, I don't mind building up the two stages to go
from 5mW to 250mW using a chip and a tube, but this feed forward correction
idea could open the door to setting up other clean linear systems from
exisiting stand alone linears I have now in the shack..
Just to double check... it requires TWO inputs: The 5mW, and the 1000D
200W module output for sampling, correct? And the big linear final would
have it's own negative feedback loop back to the tube driver, if used,
independent of the feed forward system? [assuming we don't use your 200 ohm
swamped system and still use a tube to drive the final]
The FF system would be entirely external to your FT-1KD -- It just
connects between the rig's output the outboard linear, plus an input from
the low level tap. Therefore, transportable to a new rig with a low level
out -- an easy addition, if necessary. It could even be left in line with
only a slight (1-2%) loss of power when not in use.
Regarding the link, which looks to be more of a mechanical diagram than a
schematic, it might not be GG. The final neutralization ckt. resembles a
grid driven stage. The 1st-2nd stage coupling also appears to be more
suitable for grid driven operation. Perhaps, it's 3 grid driven stages?
Where have we seen that before...
73 & Good evening,
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