--- In ham_amplifiers@..., R L Measures <r@...> wrote:
RICH SEZ.. SSB has a duty cycle of less than 20%, so it's quite
different than RTTY.
### Dream On.... unless you chopped all the audio off below
350 hz..... or the plate current meter ballistics are out to
lunch.
### Average plate current on SSB is about 1/2 that of the
dead cxr condition.
... closer to 1/3
### see above.
Average power output [not pep] is only
aprx 1/5 th the pep output of the amp.
### Next step is... we will try and meausre the heat on the
outer core with a Fluke 62 mini IR thermometer. Of
course... the heat deep inside the core will always be way
more.
Resin potting helps dissipate heat from deep in the core.
I have loads of air blown across it anyway.... and
reg is not too bad.
### I'm convinced 2 ga wire from main panel to HV supply
[and internal wiring] is not big enough !
RICH SEZ .. The Plywood Box amplifier was 100' from the breaker
box. It did 14k out pep and the wire was #4 Cu.
### #4 is too puny...esp 100' away. Heck that amounts to a
200' loop !! 4 ga CU won't handle 400+ A on peaks...
without a big v drop.... esp with 200' of loop resistance....
never mind ur small ga aluminium drop wires coming into the
house.. on top of that.
#### The next question is/was gonna be.... how was ur HV
regulation... with a dead cxr ???? [static] and also on ssb
[dynamic] ??? You can't even run a dead cxr.... with just
your 40 A breaker. You need a bare minimum of a 100 A
breaker.
### What's a fairly precise way to measure peak AC current
[under load] from the 200 A main panel ????
A 1-milliohm resistor in series with a calibrated oscilloscope to
measure the V-drop across it. The Plywood Box drew so much peak
current that the 240v wires could be heard vibrating in the attic
when I used a 30pps pulser to tune the sucker up. Also, at night,
the neighbor's porch-light blinked.
#### A 1 milliohm resistor... inserted in one leg of the 240 v
line that will handle 400 + A is gonna be a trick. Since we
know the exact length of the cable.... and it's exact dc
resistance... perhaps measuring the V drop end to end will
work?? .... or perhaps measuring the peak v across the 240v
line.... using the peak max/min function on a fluke 87 [1 msec
snap shots] .... or my scope might work... and trigger off
the 'lows' in the acv ??
### A fwb gives better reg than a doubler... for the same size
caps. That 50 ohm glitch R we have in the B+ doesn't help
matter's any.... I lose 150 vdc right there.
Later..... Jim VE7RF
