[Amps] Testing Tubes with a Henry 2K

[Brett Sims]

Appreciate the responses.  My Henry 2K also has the filaments in parallel.  Your right, it was originally designed for 3-400's.   I failed to mention in my original post, it was upgraded to 3-500's with appropriate chimneys and caps.     It works great.

So if you have a Henry 2k with filaments in parallel and currently runs two 3-500Z's with appropriate chimneys, could one test a single tube?   Wadda ya think?

Thanks  Brett   N5SQK
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


Date: Sun, 22 Aug 2021 07:58:30 -0400
From: "Mike McCarthy, W1NR" <lists at w1nr.net mailto:lists at w1nr.net >To: amps at contesting.com mailto:amps at contesting.com
Subject: Re: [Amps] Testing Tubes with a Henry 2K

Well... My 2K (original) is wired in parallel. It is also designed for 3-400's and won't accept a 3-500 unless you change the chimneys and
change the heat dissipation caps to low profile ones or lower the sockets...

Mike, W1NR

On 8/21/2021 10:40 PM, David Gow wrote:

>     The Henry 2K series amplifiers have the filaments in series so you must always have two tubes in the amp..  The manual explains why Henry
>     made this choice.  You can test a tube by having one known good tube in the amp as a constant.  After done with the spare tubes put the best in the amp
>     instead of the original constant tube.  The measurements will be relative but at least you have some indication of usefulness.  I love my 2K--3 but
>     to test tubes I use my SB-220 which has filaments in parallel
> 
>     Dave W7VM
>