[Elecraft] KPA 500 vs New 1500 watt amp

[Edward R Cole]

Congrats to all who have wanted a KPA1500 (I'm not currently a prospect):

Interesting misconceptions already "flying"
"1500w cost three times 500w"

KPA1500 with internal tuner = $5995
KPA500+KAT500 = $2684.95*
5995/2684.95 = 2.23
*April special price

Power requirement 240vac @ 20A = 4800w
But likely the amp will draw 1500w/0.7 = 2143w (or so) plus maybe 
200-300w for solid-state control ckts
call it 2400w in round numbers or 240v @ 10A (just my guess)

My 6m 1000w PA draws 50A @ 50v = 2500w (40% eff. with 16 transistors)
My 2m-8877 1400w PA draws 750ma @ 3700v = 2775w (50% eff. but with 
tired old tube)

20A is a convenient 240v value since breakers for that are readily 
available;  I ran about 45-feet of No. 8 wiring to bring 240vac to my 
shack where I use a 60A breaker box with a 20A breaker (only tripped 
a couple times in several years useage - HV flashover & HV 
transformer failure).

I ran my own 240v run as I tired of waiting five months for the $700 
Electrician to show up.  I think the 4 cond. No. 8 cable ran about 
$1.50/foot plus costs for 30A 240v twist lock connectors/outlets & 
60A utility box with three breakers.  I see 2v drop on 240vac under 
load of the 8877.

KPA1500 nice design using separate 50v switching PS.  Many new ham 
radio PA's coming out that use 50v so this could be multi-use PS.  I 
would like a 2m 1500w sspa using LDMOS to replace the 8877 & 
HVPS.  Not looking for that from Elecraft (I will probably buy a kit 
from W6PQL).

PS: if I were in market for HF QRO the KPA1500 would be my choice!  I 
finally upgraded to the KXPA100+KXAT100 for my HF/6m needs (driven by 
either KX3 or K3/10).

73, Ed - KL7UW
   http://www.kl7uw.com
Dubus-NA Business mail:
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