[Amps] Step Starting the 3CV1500A7

[Robert B. Bonner]

I agree Paul,

I would feel more comfortable doing things in order too.  Its prolly all
those years as an airline pilot, grab the check list and....

Shack lights, antenna switch, rotor control, audio rack, 7800, blower,
filaments, grid bias, plate, screen grid, T/R supply.  Then sit there for a
few minutes watching for smoke or fire before closing the key.  Clunk
HUUUUMMM.

I suppose a big sequencer could be built.

But seriously, the tube isn't going to conduct until the heater comes up
anyway.  So why not just walk in the shack, hit one giant 100 AMP disconnect
and watch the whole world spin up in front of you?

You could say something catchy like "illuminate" or "You turn me on" and hit
the big switch. It would be like hitting the main switch on a Carnival
Carrousel.

With the way things are going in this world, a guy has just got to have some
level of entertainment.

BOB DD

-----Original Message-----
From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
Behalf Of Paul Christensen
Sent: Wednesday, February 07, 2007 6:02 AM
To: Amps Amps
Subject: Re: [Amps] 3CV1500A7

> internal resistance to limit start-up current. (I don't trust it's
> step-start circuit to provide a suitable slow-rise since the HV isn't
> brought on-line until the timer completes it's cycle)

Great points, Dennis.  I have often thought about adding a separate HV 
contactor relay to both Alpha amps for the purpose of applying HV at some 
reasonable time after lighting filaments.  My gut has never been comfortable

with HV being applied to the anode at the instant when filaments are lit.

Of course, with indirectly-heated tubes, the real issue is to refrain from 
RF excitation until the cathode comes up close to filament temperature.  But

even on the 70V with its directly-heated cathode, I would probably "feel 
better" with something like a 5-10 second HV delay.

Paul, W9AC 

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