The arc is at the step start contacts just as it makes contact to short out the step start resistor.? The delay is a bit short.
-----Original Message-----
From: DupyRail <andymueller@...>
To: ham-amplifiers <
[email protected]>
Sent: Tue, Jan 28, 2020 3:02 am
Subject: Re: [ham-amplifiers] Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
Being curious, what exactly is arcing?
Andy? K9ATX
On 1/27/2020 6:05 PM, Cliff Fox (KU4GW)
wrote:
I have a Ameritron AL-1200 brought to me by the KN4UNA, P.J., who
received the amp from his uncle's estate (W4WWF Dale Mash SK) and
it has a problem with giving a arc when the power switch is first
turned on. The amp runs fine after that initial arc. Can anyone
offer any advice on what I should check that may be the cause? I
own a AL-80B and I know it has a inrush current step-start circuit
in it to prevent a surge, but know nothing about the AL-1200. Does
it have inrush current protection or a step-start circuit? I had a
issue with my AL-80B a while back arcing from the tube parasitic
resistors to the shaft going to the band switch. I wrapped the
shaft in heat shrink tubing and that solved that problem. What
should I check first in the AL-1200, perhaps a current limiting
resistor? The amp is as clean as a pin and looks like brand new!
Thanks in advance and very 73!?
Cliff, KU4GW
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"Where the Old Soo crossed the New Soo"
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