On Oct 2, 2006, at 3:25 PM, pentalab wrote:
--- In ham_amplifiers@..., "Peter Voelpel" <df3kv@...>
wrote:
What is your reason for that large capacitor?
Are you using single phase at that power level?
I only use 2?F maximum or NONE in my large power supplies, so my
glitch resistors and magnetic breakers in the primaries of the
transformers is all I need
73
Peter, DF3KV
### You gotta be kidding us right ?? 2 uf or NONE !!
2uF in a FWB is enough for a 4-1000A at 6kV.
### here in NA... although 3 phase power [typ 12.5 kv /14.4 kv
and now 25 kv] is distributed all over town..... only one
leg /phase of that appears in residential area's.... where it's
dropped down to 240 /120 v [ they all use a grnded CT on the
sec]
### Typ pole pig xfmrs are 25/50 kva for multiple homes.. and
smaller for a single home in the countryside. How 16 homes
can all share the same 50 KVA xfmr [and all have "200 A"
service] is beyond me !
Indeed, and it's all because of greed. . During the recent heat
wave in Southern California, transformers were popping like popcorn
in residential areas because Southern California Edison originally
cut costs by installing transformers that were Way too small. For
example, on our block, a 50kva transformer supplies power to c. a
200kva max load. During one heat spell, the transformer got so hot it
broke a seam and started to leak coolant oil. Edison's fix was to
replace it with another 50kva unit.
### 3 phase 208v/120v is used for business's.... and
condominium's, apartment flats etc. Even there.... each floor will
only get 208/120 single phase power... per suite. They make
special 208 v electric base board heater's. Stuff like 240 v
electric stoves.. and 240V electric hot water tanks/ 240 v
electric clothes dryer's.. are used on 208 v.... and just take a
little longer to heat up.
### For a single phase RF deck that needs say 6900V @ 3A... a
bare minimum of 34 uf will provide barely 3% ripple.
A 100 uf filter will provide 1% ripple... and far better
DYNAMIC Regulation.
And nobody on the Rx-end can hear the difference, Jim.
...
R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org
