Geoff wrote:
Gary Schafer wrote:
I know full well that there is no such thing as a 375 watt carrier
limit to AM power in the FCC rules. I never said there was.
Ok, good. I was just making sure ;) Too many people believe that
there's some 'magical mystification' about 375w of carrier output being
the 'legal limit'.
I was trying to "clarify" Ronnie's statement about how much power he
runs his 813's at when he says he runs them at legal power out.
And since we don't know if Ronnie has a symmetrical voice pattern or
otherwise, we can only assume it is symmetrical when discussing
general power principles.
Maybe he has the peaks phased so maximum peaks are in the negative
direction? I don't know. Either way it appears as though he only has
enough headroom for less than 50% modulation in the positive direction.
Agreed, there. And, I've been to Ronnie's shack. I'm pretty sure he
doesnt' do any audio shaping, or phasing, or any other audio tricks on
either the Ranger or the Globe King 500 he's running there.
On top of that the plate dissipation is around 380 watts per tube if
the amp is tuned properly, which it can't be if it is not burning up
tubes.
That is the whole point, if you are paying attention. :>)
I was... it was just the 'legal limit' that caught my attention (yet
again ;->)
Maybe you could tell us how much peak envelope power would be
available from a pair of GG 813's at 375 watts carrier out with 100%
modulation?
I'm not sure you can get more than around 1kW PEP output of a pair of
813's... and probably more like 800w. (3) in parallel would be a
different story, though.
73 = Best Regards,
-Geoff/W5OMR
I would say you are pretty much on the mark there. I have a pair of
813's in GG also. I only run them at around 2500 volt and can get about
650 watts max out with 100 watts drive if I remember right.
I ran them well over 3000 volts many years ago and got quite a bit more
out of them but didn't have a decent watt meter then so I don't know
exactly.
1000 watts out seems doable but they will be running around 1600 watts
or more input. They will turn pretty red. Even on SSB at that power.
73
Gary K4FMX
