[Amps] 120 hz hum

[Jim Thomson]

Uhh....Im not complaining about the LK-500 regulation, simply stating a 
fact.

Now if you want to look at the classic Alphas of the 7 series, Ameritron, 
Ten Tec, Heath, Dentron, Drake, Swan, etc, etc, you will find them in the 
17-33uF range....duh.

The latest series of some amps have more C as a result of capacitor 
technology, not engineering brilliance.

Going back further to the 1963 NCL-2000 it is 10uF AS PER THE RCA specs for 
the 8122's. Static regulation at 0 to 2000W is 16%. Dynamic is much better 
for SSB.

Carl

##  well, I guess RCA  got it wrong !  

## yes, cap technology has really improved a whole bunch. 

##  A buddy of mine lucked out, and found some spanky new 
450 V  lytics....   4800 uf   [ four thousand, eight hundred].. EACH.  ESR on them is 
.025 ohms [25 milli-ohms] 

##  Ripple  current rating is 40A  !     I checked both Hammond's and CD's
engineering notes, and went through all the math's, and sure enough, with a simple
 C input filter, ripple current = 2.56 x DC plate current.  

## Anybody who doubts the virtue of really high C  filters, just try it.  The PEP 
output on the wattmeter is WAY up. Ripple is almost zero. I'm 100% convinced IMD
is down as well.  For folks who play with ESSB, you can actually hear the difference
between  stock C value... and  2-6 X  stock C value.  

##  step start procedure is much the same.  The step start resistor value has to be
 reduced in value, and  shorted out after a longer time period. This will eliminate the 
sec surge.  Caps  charged up to only 1/2 normal B+.. will only have  1/4 of the energy.
Joules =  uf  X   [B+  squared] .../  2 million.      Caps  charged up to 71% of normal B+ 
only have 1/2 the energy.   So you can see, to minimize the sec surge, you want to charge
the caps up as high as you can.. just prior to shorting out the step start resistor.. which may
be several seconds.  A lower value R means less V drop across the same step start R, and
higher B+..prior to shunting the R.  

##  they never can be fully charged with normal step start R... because the magnetizing current
in the plate xfmr pri.. is always flowing through the step start R.    Another method to step start
is to use a small variac in the pri, and switch it out of the circuit completely, with a small relay.
This method allows the caps to be charged up to 99%  of normal B+... and no sec surge.[and
no pri surge either]. 

later..... Jim  VE7RF