Praying
----- Original Message -----
From: "Mike Lord" <k4elv@bellsouth.net>
To: <amps@contesting.com>
Sent: Wednesday, September 21, 2011 3:25 PM
Subject: [Amps] NOS 811's & 30L1
>I just completed the restoration of a 30L1, i.e., new Harbach board,
>"matched set" of 811's. Brought the unit up slowly with a Variac. 110 VAC
>line voltage, 1800 VDC unloaded on plates. All seemed ok. Hooked up the
>unit to the rig. Turned the 30L1 on and blew up the glitch resistors.
>Smoked up the place. Checked the unit for damage beyond the glitch all
>checked ok. Brought the unit up slowly with the Variac and at about 400
>VDC one tube began showing purple glow and slight arcing. Changed out the
>tube and all was well. Here's my question. The 811 vendor tells me the
>problem is the 1800 VDC on the plates. "Too much for an 811" I realize
>the caps on the Harbach are large thus more B+, but there have been many of
>those boards sold. The 30L1 book says 1600 VDC unloaded. The 811 is rated
>at 1500 V. So what are all the 30L1 owners doing besides changing over to
>a 572B?
>
> Thanks. Mike K4ELV
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