3-500's

[john]

Just make sure filament voltage is not higher than nominal...which, if your 
line voltage is high, it will be.

This and temperature, are probably the most aggrivating factors in tube life...

John





At 01:11 PM 5/7/2005, Ray Friess wrote:
>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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