--- In ham_amplifiers@..., R L Measures <r@...> wrote:
RICH SEZ... I did the calculations for the 8170 amplifier with
Ohm's Law. The calc. peak mains current was c. 300A. The
measured result was 1200v- pk into 50-ohms on SSB.
### 1200 V pk equates to 14,396 watts pep output into a 50 ohm
load....14,395.65 /.63 = 22,850 w dc input. Primary VA = 22,850
x 1.22 = 27,877 va 27,877 /240v = 116.155 A .... not
including fil xfmr, blower etc. Peak current is aprx 375A
with big wire and a big C filter... every 8.3 msecs.
### Rich... tell us how you take a steady state plate and grid
current meter readings..... with out blowing ur under rated 40 A
house breaker ???? IE: a dead cxr... for just 3-6
seconds... just long enough to measure grid/plate current + fil V,
loaded plate V, etc. Forget the fil v/ plate v...... focus on
just the plate + grid current.
### If u just pulse tune it...and talk...fine... I do too. Unless
both ur plate/grid meter's are peak reading types.... I can't see
how it's done.
### IMO.. the entire system should be configured to at least
handle a 4-7 second dead cxr.... without blowing breakers,
melting coax, frying tank coils etc.
### For a 8170/8171.... I'd use a 100A breaker... and a bare min
of 2 ga wire... and considering the 300-400A peak current draw
every 8.3 msec..... 3 x 000 CU is the real ticket.... regardless
of length.
### BTW... what's the CCS rating of the SB-220's plate
xfmr ??? I heard it was 1200 va. Now Rich has stated it's only
600Va. I'm sure the smaller SB-200 is 600 va CCS.
### Will a SB-220 stock... in good condition, on low plate
V...be capable of delivering 600W CCS RTTY ??? If so...
the plate xfmr would have to be a 1200 va unit.
Later... Jim VE7RF
#### 3/000 CU from main 200A panel to HV supply is what's
really needed. Snip a few strands to make it fit the 100 A
breaker at EACH end.
later... Jim VE7RF
R L Measures, AG6K, 805.386.3734
r@..., rlm@..., www.somis.org
