[Amps] Glass tube plate color

[Carl]

----- Original Message ----- 
From: "Barrie Smith" <barrie at centric.net>
To: <amps at contesting.com>
Sent: Sunday, August 15, 2010 2:02 PM
Subject: Re: [Amps] Glass tube plate color


> Carl and all:
>
> Thanks for the responses.
>
> I did swap the tubes, as Carl suggested.  The brightest glow stayed on the
> right.
>
> So, I suppose I have some sort of circuit imbalance.
>
> Since the visual imbalance is only slight I wonder what to do about it, if
> anything?
>
> 73, Barrie, W7ALW

I suspect the neutralization on one tube isnt perfect and its drawing more 
Ip at resonance. You can try a very slight tweak of its Cn and see which way 
the color goes. If it gets brighter go the same amount the other way.

Carl
KM1H


> ----- Original Message ----- 
> From: "Carl" <km1h at jeremy.mv.com>
> To: "Barrie Smith" <barrie at centric.net>; <amps at contesting.com>
> Sent: Sunday, August 15, 2010 10:45 AM
> Subject: Re: [Amps] Glass tube plate color
>
>
>> What happens when you swap positions?
>>
>> Carl
>>
>>
>> ----- Original Message ----- 
>> From: "Barrie Smith" <barrie at centric.net>
>> To: <amps at contesting.com>
>> Sent: Sunday, August 15, 2010 11:55 AM
>> Subject: [Amps] Glass tube plate color
>>
>>
>>> Speaking of class C, I have just completed a nostalgia rig using a
>>> push-pull pair of VT-127As (somewhat similar to the 100TL, but looks 
>>> like
>>> a spaceman with grid and plate pins sticking out the sides).
>>>
>>> I've been bench-testing it the last few days with a wimpy power supply.
>>> Surprisingly, I'm up to 500 wattts out with 1300 volts on the plates.
>>>
>>> I have several tubes, and have tried a couple of different pairs.  In
>>> both instances I've noticed that one tube will have a slightly brighter
>>> plate glow than the other.
>>>
>>> I'd like to have the tubes as closely matched as possible.
>>>
>>> My question is:  Which tube is most likely to be the better, the bright
>>> one, or the cooler one?
>>>
>>> 73,
>>> Barrie, W7ALW, DN36au,
>>> QRV 6M, 432 & 1296 EME
>>> _______________________________________________
>>> Amps mailing list
>>> Amps at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>
>>
>>
>
>
>
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