[Elecraft] Ameritron 240V inrush limiter: any benefit on a KPA500?

[David Wilcox]

Guys,

This is very interesting. Is there a Wiki site where all your explanations are collected together.  I am Interested in the magnetization of the iron in the transformers and the effect of the turn on current phase causing an over magnetization of the iron core and drawing too much current at first.  This is all new to me.  Just an interest as I have never run over 100 watts and usually 5 - 10 watts is enough for me.  

Also, how do those inrush devices work?  I have seen them offered for the old Heathkit amps.

Thank you.

Dave K8WPE since 1960 always learning something new from you guys and gals.

David J. Wilcox K8WPE’s iPad

> On Jan 19, 2020, at 12:51 AM, Vic Rosenthal <k2vco.vic at gmail.com> wrote:
> 
> Just like the 1930s vintage Western Electric at WKOP when I worked there in the early 60s. When you turned it on, it went click-click-click-click BLANG.
> Two tubes, 12 kV on the plates, about 1 amp plate current for 5 kW output.
> 
> Victor 4X6GP 
> 
>> On 19 Jan 2020, at 1:45, Fred Jensen <k6dgw at foothill.net> wrote:
>> 
>> 10 KW homebrew FM broadcast TX [not kidding -- KPFK 90.7 Los Angeles in the late 50's, 4 4-1000A's* in parallel driven by a 1 KW stage] had a step-start using mechanical time-delay relays.**  It limited the inrush current to the filter capacitors of the 5.5 KV plate power supply.  It was part of the power supply in the back room, not the PA.
>> 
>> 73,
>> Fred ["Skip"] K6DGW
>> Sparks NV DM09dn
>> Washoe County
>> 
>> * I do *not* recommend 4 ea 4-1000A's in parallel at 90.7 MHz. Things got very hot.
>> 
>> ** Integrated circuits and microprocessors has not been invented then.  Actually, the transistor barely had been.
>> 
>>>> On 1/18/2020 10:55 AM, Roger wrote:
>>> NO amplifier needs inrush protection - it is the POWERSUPPLY that needs it
>>> no matter how it is implemented.
>>> So the answer is not an easy "NO" or "YES" but a definite "it depends"!
>>> 
>>> Roger, DL5RBW
>>> 
>>> 
>> 
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