Hmmm. OK .. guess everything is bigger in Tejas ... including Ohm's law!
HIHI ...
Let's do a "what-if" ... IF you had 24Ø VAC Single ~ --- you ran it down
25' of #16 copper ... and you were running a "Tejas KW", of 5.7 KW input,
key down (say, FM, RTTY, Digital, AM, or CW with a brick on the key) --
which should get the 1.5KW legal output rather handily, actually more like
3+KW .... a single 4-1ØØØ does 2.5 KW handily, capable of a wee bit more ...
depending on amp design, of course ... THAT would require 25 amps. So, we
have 24Ø V, 25 amps, 25 feet of "waaaarrrrr" ... AWG 16 --- the voltage
drop would be ... tah dah! 6.1 volts.
233.9 VAC delivered to the xfmr. Do the math, Phil ...
By the way, of course, on the OTHER hand, by increasing the wire size to
#1Ø, there is considerably less voltage drop .... you get 4.6 more
olts - All the way to 238.5 at the business end! Mind you, this is
assuming you're running over 5KW input to the amplifier. About 1ØØ Volts
on the output side ----- again, if you are running 5.7 KW. By the time
the rest of the power supply components get into the mix ... the caps, the
choke(s), the diode losses, the bleeders, metering, etc .... that voltage
difference is essentially nil. (With number 4, you would only lose about
1/2 volt.)
But, you are correct ... if one is to run a 4CX-1ØØØØ at full tilt, you need
some serious "waarrrrr". Holy Cow, the filaments require over 56Ø watts! As
to rewiring the ham shack ... does the term "3-Phase" strike a bell?
You might want to consider some other coax too .. Andrews line, with dryer!
The first FM transmitter that I was chief for used one of these ...
Cheers, tnx conversation ..
From: "Phil Clements" <philk5pc@tyler.net>
To: "AA6DX" <aa6dx@pacbell.net>; "Jim Isbell"
<millenniumfalcon@cableone.net>; "Mail list Amplifiers"
<amps@contesting.com>
Sent: Wednesday, April 21, 2004 2:19 PM
Subject: Re: [Amps] Serious design stage
>
>
>
> > Hmmm .. just wonder why the large wire requirement, Phil? We are
> not
> > connecting a restaurant size `lectric range here. Assuming we are
> talking
> > AWG size wiring, the current carrying capabilities @ 230-240 VAC,
> single ~
> > is about:
> > #4 = 37,000 watts
> > #6 = 27,000 watts
> > #10= 13,800 watts
> > #16= 5,750 watts
> > (Approximately, safely ... your mileage may vary!)
> > Is that not correct?
>
> That is not correct because you did not specify a length.
>
> I don't like warm wiring inside my walls, so I spring for a few bucks
> more for cable
> when I wire a ham shack. My service here is 37 kva from the street
> transformer.
> The power company chose to run size 0 wires for the 50 foot run to my
> service
> entrance panel. I guess we are conservatives down here in Texas!
>
> The bottom line is that you do not want anymore system voltage drop
> than is absolutely
> necessary.
>
> I was also advising the wire size not for a 4-1000A, but for the
> monster transformer
> the guy has there. If Rich convinces him to try a 8171 amp at a later
> date, he will not have to
> rewire the ham shack.
>
> (((73)))
> Phil, K5PC
>
>
>
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