[Amps] Life of tubes in ham service - Correction

Jim W7RY jimw7ry at gmail.com
Tue Dec 26 20:23:13 EST 2017

A simple resistor in series with the filament transformer and shorted by a 
relay after a second or two is MUCH easier.

Jim W7RY

-----Original Message----- 
From: Mark, K5AM
Sent: Tuesday, December 26, 2017 6:27 PM
To: amps at contesting.com
Subject: Re: [Amps] Life of tubes in ham service - Correction


Should have said fig 5 on page 7. The heater regulator limits the heater
current to slightly over the normal level. This provides a slow warm-up.
It takes over a minute to reach normal heater voltage in this amp.

Original post:

A recent post by Leigh, VK5KLT, suggested:

> ...  a soft-start mechanism on
> the filaments to bring them up slowly in a controlled
> manner at initial switch-on ...

One method for this is found on page 8 of:

A Luxury Linear, QEX, May, 1996, 3-12.



Mark, K5AM

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