KPA-500: 120vac vs. 240vac

[RLVZ]

Hi Guys,
 
Wondering if anyone has tested their KPA-500 on both 120v. and  240v. and
documented the following:
 
1) When operating on 240v. was the PA voltage under  load the same, higher,
or lower than when operating at 120v.?
 
2) When operating on 240v. was the same, less, or more drive  required for
the same power output?
 
3) Did the KPA-500 PA temperature  while contesting stay the same,
decrease, or increase?  
 
Thanks!
 
Dick- K9OM
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[Don Wilhelm-4]

Dick,

Any differences between the 120 and the 240 volt AC input have more to
do with the wiring between the breaker panel in the house and the
hamshack.  Length of wire, wire size, tightness of the connectors and
receptacles.  Twice as much current is drawn at 120 volts vs. 240 volts,
so the IR drop in the AC wiring will be half.

For any particular DC PA voltage, there should be no difference in drive
level or heat dissipation, so that depends on how the user has set the
transformer tap rather than the AC input voltage.

73,
Don W3FPR

On 12/27/2011 4:10 PM, [hidden email] wrote:

> Hi Guys,
>
> Wondering if anyone has tested their KPA-500 on both 120v. and  240v. and
> documented the following:
>
> 1) When operating on 240v. was the PA voltage under  load the same, higher,
> or lower than when operating at 120v.?
>
> 2) When operating on 240v. was the same, less, or more drive  required for
> the same power output?
>
> 3) Did the KPA-500 PA temperature  while contesting stay the same,
> decrease, or increase?
>
> Thanks!
>
> Dick- K9OM
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

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[Jim Brown-10]

On 12/27/2011 1:27 PM, Don Wilhelm wrote:
> or any particular DC PA voltage, there should be no difference in drive
> level or heat dissipation, so that depends on how the user has set the
> transformer tap rather than the AC input voltage.

Because the KPA500 power supply is not regulated, the total regulation
will be a bit better running from a 240V source, assuming the same size
conductors for both circuits.

73, Jim K9YC
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