Date: Sat, 24 Jan 2015 12:53:21 +1030
From: "Leigh Turner" <invertech@frontierisp.net.au>
To: "'Bill Turner'" <dezrat@outlook.com>, <amps@contesting.com>
Subject: Re: [Amps] 5 Minutes for Ameritron 811H to warm up?
Personally I wholeheartedly concur with your sentiments here Bill; most of
my shack amps are of the ceramic tube variety and indeed do seem to last
forever.
My only exception amp is the venerable Kenwood TL-922 with its nostalgic
pair of Eimac 3-500Z glass bottles...they too have proven very reliable
workhorses! The proviso rider with any tube is absence of abuse.
73
Leigh
VK5KLT
## whats the most anybody has gotten out of these russian ceramic wonder tubes
like GU-74B etc ?? Can you get 20 years out of them, beating on em 7 days a
week,
like an Eimac 3-500Z ?
## What is longest anybody has gotten out of an Eimac 8877 ??
## at least with the bigger eimac ceramic tubes, like 3x3, 3x6, 3x10, 4x5,
4x10,
they can be re-built till hell freezes over, unlike their throw away, smaller
ceramic
siblings. IMO, you get a bigger bang for the $ with the bigger ceramic
tubes, esp
since being thoriated tungsten fil, you can reduce the fil V way down, like 12%
or more,
further extending tube life. Take a 3x3... rated for 2.5 A CCS plate
current...then run it
at 1.5 to 1.7 A plate current..alon with reduced fil V. It will last forever.
The typ 2 x 3-500Z amp is rated at 800ma max plate current.... and my L4B runs
at 800ma..just to get 1290w po.
Jim VE7RF
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|