[Amps] 10 kw CCS on 6M

[Joe Subich, W4TV]

> So, where does that drive power go while the driver(s) are being 
 > tuned, and the final is on standby?

Drive power is relatively low and typically dissipated in the grid
circuit of the succeeding stage.  For example, the BTR1 (pair of 4-400 
modulated by a P-P pair of 4-400) - one of which is in my garage - has
a single 6146 driving the grids of the 4-400s probably less than 50W
carrier drive for 1 KW carrier output.

> Based upon that description, when WLW was running a full 500KW, I'd 
> assume the engineer would set the carrier around 125KW, and then 100%
> modulation would peak at 500KW.
Nope ... that 500 KW was carrier power as is typical for AM broadcast.

The RCA BTR-1 is spec'd for 1 KW AM and will certainly do 5 KW PEP (125%
positive modulation) if one were using a scope to look at the output.

73,

    ... Joe, W4TV


On 2022-09-12 6:06 PM, Donald Fox via Amps wrote:
>   One of the things I see that is different, as I have watched videos of the bigger transmitters firing up, is that they can bring the driver stages online, and have them drawing plate current, tune them, and then engage the final. Obviously, there is not tx/rx relay for a plain transmitter. So, where does that drive power go while the driver(s) are being tuned, and the final is on standby? There are plenty of such videos out there that are exciting to watch!
> 
> FM of course, does not have any 'swing", so you crank the carrier where you want it to be, and it just sits there. AM on other hand of course, is set for about 25% of max carrier, and them modulation takes it up and down from there. Based upon that description, when WLW was running a full 500KW, I'd assume the engineer would set the carrier around 125KW, and then 100% modulation would peak at 500KW.
> 
> Any way you slice it, that is a bunch of RF up the feedline!
> 
> Don N8ECH
>