[Amps] plasma inside 3-500Z TSPA

[John T. M. Lyles]

That photograph of the bright glow in the 3-500Z is exactly what i 
saw when I tested my Continental 314R1 power rock AM transmitter when 
the PDM damper diode was shorted. When HV came on, the main breaker 
tripped quickly. In the short blast, the 3-500Z switch tube was being 
driven with 8500 volts on the anode, into a short circuit with nearly 
zerop bias. The tube survived it fine and is still in use.

73
John
K5PRO


>
>Message: 8
>Date: Fri, 28 Jul 2006 10:51:44 -0400
>From: "Tom W8JI" <w8ji at w8ji.com>
>Subject: [Amps] Arc distance and plasma
>To: <amps at contesting.com>
>Message-ID: <000c01c6b255$5c8b86d0$640fa8c0 at radioroom>
>Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>	reply-type=original
>
>Rather than claim I can look at a tube and magically tell
>what happened years ago with my magnifying glass,  I thought
>I would add a picture of a 3-500Z under RF plasma
>conditions.
>
>The photos clearly show then concentration of plasma during
>a hard fault.
>
>http://www.w8ji.com/fault_protection.htm
>
>Enjoy.
>
>73 Tom