3-500's

[Ray Friess]

I'm not sure about the drive power being applied in increments... 
However, when it comes to
the subject of leaving the filaments on for an extended period of time, 
I can offer a bit of advice
from personal experience...

In my case, I was getting ready to put a 30L-1 on the air (four 811 
tubes, not the 3-500z tubes)
and I turned on the filaments for a few minutes to check on the fan 
operation, etc.
I got distracted and left the shack for the night.   It was the next 
morning when I went back down
into the shack that I noticed the amp was still powered up.    It had 
run in standby with the filaments
on all night long (about 8 hours).   Nothing had gone wrong or shorted 
or anything like that.... it was
in perfect shape.

So, I would say dont worry about leaving the 3-500 filaments on for 10 
hours.   Unless youre worried
that the filter caps or other power supply components may be a bit sour 
and could go if powered up
for an extensive period of time, you should have no problems.   It wont 
be much different than if
you left the shack lights on all night.    A filament is a filament 
...    leaving a light bulb on all night doesnt
harm it, and while a tube filament is a bit different than a light bulb 
filament, the principle is the same...
so there shouldnt be any problem....



Dave Leisman wrote:

>I just purchased a pair of new 3-500 zg amplifier tubes, and I have 
>been told that they need to be "broken in", e.g., that I need to put 
>them into their sockets, and turn on the amp for 10 hours of filament 
>voltage before applying any exciter power to the amp.
>
>Also, I was told that when I finally do apply power to the amp I need 
>to do so in increments of 10 watts, starting at the 10 watt level up 
>to a maximum of 100 watts.
>
>I'd sure appreciate some input here.  These tubes are expensive and I 
>don't want to mess these up, but on the other hand simply leaving this 
>amp turned on, and unattended, for some reason, makes me nervous as 
>well. 
>
>Thanks in advance es 73's
>
>
>  
>

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