Yes, more accurately a step-start. Regardless, that’s reassuring to know!
Kim N5OP
"People that make music together cannot be enemies, at least as long as the
music lasts." -- Paul Hindemith
> On Dec 27, 2017, at 06:25, Jim W7RY <jimw7ry@gmail.com> wrote:
>
> Soft start (I call it step start) does reduce filament inrush current. As
> long as it's on the filament transformer primary.
>
> Which it is in the SB200, SB220, TL922, L4B and TenTec Titan... And many
> others.
>
> 73
> Jim W7RY
>
>
> -----Original Message----- From: Kim Elmore
> Sent: Tuesday, December 26, 2017 9:58 PM
> To: Warren Volz
> Cc: amps@contesting.com
> Subject: Re: [Amps] Soft Start
>
> A related question. Once long ago I read that power cycles are very hard on
> filaments. Is that also the case with soft starts, or does the soft start
> reduce the thermal shock issues?
>
> Kim N5OP
>
> "People that make music together cannot be enemies, at least as long as the
> music lasts." -- Paul Hindemith
>
>> On Dec 26, 2017, at 21:08, Warren Volz <warren@warrenvolz.com> wrote:
>>
>> I’d recommend a step start with fuses. I have w7ry’s board in my sb220 and
>> the fuses saved me from a bad tube once already.
>>
>> -Warren
>>
>>> On Dec 26, 2017, at 8:59 PM, Jim W7RY <jimw7ry@gmail.com> wrote:
>>>
>>> I recommend 10 Ohms. I use 2 resistors and 2 relays. There are fuses in
>>> series with the resistors to protect them.
>>>
>>> Why would a cap blowing up cause an issue with a step start circuit?
>>>
>>> Again, I use 2 resistors and 2 relays on a small circuit board.
>>>
>>> See:
>>>
>>> https://www.ebay.com/itm/282765541853?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649
>>>
>>> 73
>>> Jim W7RY
>>>
>>>
>>>
>>>
>>>
>>> -----Original Message----- From: Arnie Pfingst
>>> Sent: Tuesday, December 26, 2017 8:31 PM
>>> To: amps@contesting.com
>>> Subject: [Amps] Soft Start
>>>
>>> Once upon a time, i had a capacitor explode upon start up. I've heard
>>> stories for and against adding a soft start circuit to my amplifiers.(Some
>>> say 20 ohm resistors, and others say 30 or 40 ohm.) That and the price of
>>> replacement tubes. In my case i have two TL 922a amps using 3-500z tubes.
>>> Both set up on 240vac. What do you all have to say here. Thanks
>>> Arnie
>>>
>>>
>>>
>>> Sent via the Samsung Galaxy S8 Active, an AT&T 4G LTE smartphone
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>>
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