Rich,
It couldn't be matched to the load via the tank circuit so something is going
to back up causing excessive current. I was trying to get out of parasitics on
this thread. I'll let you all hash this out, I've got too much on my plate now
: )
Best,
Will
*********** REPLY SEPARATOR ***********
On 7/25/06 at 2:09 PM R L Measures wrote:
>On Jul 25, 2006, at 7:18 AM, Will Matney wrote:
>
>> On 7/25/06 at 6:08 AM R L Measures wrote:
>>
>>> On Jul 24, 2006, at 9:03 PM, Will Matney wrote:
>>>
>>>> Keith,
>>>>
>>>> Excessive grid current did, either from being over driven, or an
>>>> arc from a gassy tube.
>>>
>>> Will M.: Could an unloaded condition cause excessive grid current?
>>
>>
>> Sure, there's others. I only said two quickly off the top of my head.
>
>If the HF tank is a low-pass design, and the tube happens to be
>oscillating in the VHF range, would the anode be loaded or not?
>>
>>>>
>>>> Best,
>>>>
>>>> Will
>>>>
>>>> *********** REPLY SEPARATOR ***********
>>>>
>>>> On 7/24/06 at 10:28 PM Keith Dutson wrote:
>>>>
>>>>> I am not talking about AFTER the fuse blows. What current CAUSED
>>>>> it to
>>>>> blow?
>>>>>
>>>>> Thanks.
>>>>>
>>>>> Keith
>>>>>
>>>>> -----Original Message-----
>>>>> From: amps-bounces@contesting.com [mailto:amps-
>>>>> bounces@contesting.com] On
>>>>> Behalf Of Will Matney
>>>>> Sent: Monday, July 24, 2006 9:33 PM
>>>>> To: amps@contesting.com
>>>>> Subject: Re: [Amps] "Tubes 201" - How Vacuum Tubes Really Work
>>>>>
>>>>> Keith,
>>>>>
>>>>> Since it's loose from ground, and no corcuit can be made, it
>>>>> hangs in
>>>>> space,
>>>>> and can only be acted upon by the electron flow from the cathode.
>>>>> In this
>>>>> case, if the grid is slightly more positive, it will accept some
>>>>> electrons
>>>>> thus bringing it to 0 volts or slightly negative to ground. This
>>>>> is called
>>>>> coming into equilibrium or equalling out. If the tube is not
>>>>> slightly
>>>>> positive, it will not accept any electrons, and the electron flow
>>>>> will be
>>>>> opposed by the grid. Terman, and I think the author of Tubes 201
>>>>> discuss
>>>>> this. In any case, the grid can never be made positive by these
>>>>> actions
>>>>> taking place.
>>>>>
>>>>> Earlier, when Rich mentioned about grids, I thought he meant a grid
>>>>> becoming
>>>>> positive. Bill posted what he meant which is correct and the same
>>>>> as above.
>>>>> I privately told Rich of this, and am sorry I questioned him, it
>>>>> was a
>>>>> mis-understanding. We actually were meaning the same thing at the
>>>>> time.
>>>>> Rich
>>>>> like me does not believe a grid can become positive by being
>>>>> bombarded by
>>>>> electrons. Even if a grid gets to the point of emitting electrons
>>>>> from
>>>>> being
>>>>> hot, they are replaced by the electron flow from the cathode. By
>>>>> reading
>>>>> some other texts, none of those do either.
>>>>>
>>>>> Best,
>>>>>
>>>>> Will
>>>>>
>>>>> *********** REPLY SEPARATOR ***********
>>>>>
>>>>> On 7/24/06 at 9:15 PM Keith Dutson wrote:
>>>>>
>>>>>> I am totally lost on this excessive grid current discussion. If
>>>>>> there
>>>>>> is a resistor or fuse tied between the grid and chassis and it
>>>>>> blows,
>>>>>> the grid obviously has a potential above or below ground. Which
>>>>>> is it?
>>>>>> Can it be either depending on the fault?
>>>>>>
>>>>>> 73, Keith NM5G
>>>>> [snip]
>>>>>
>>>>> _______________________________________________
>>>>> Amps mailing list
>>>>> Amps@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Amps mailing list
>>>> Amps@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>
>>>
>>> R L MEASURES, AG6K. 805-386-3734
>>> r@somis.org
>>
>> Best,
>>
>> Will
>>
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>>
>
>R L MEASURES, AG6K. 805-386-3734
>r@somis.org
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