[Amps] Tube swap

[Steve Bookout]

I think most people would use something called a high potential tester AKA 'HI-POT' tester.  It allows you to put a variable high voltage across your tube from various pin combinations.  There is a high value resistor in the test lead to limit the current when you find a voltage high enough to start to conduct thru the partial vacuum.
Mine was made with an electric igniter from a furnace.

Used on vacuum tubes, vacuum capacitor, vacuum relay as well as air dielectric variable caps to qualify them as to not arcing at the desired voltage.

Others may explain better, as I've been discussing politics with Capt. Morgan.

de Steve Bookout
steve at nr4m.com
www.nr4m.com



On Jan 27, 2014, at 9:56 PM, "Karel" <kebenstr at bmts.com> wrote:

> How do you check if they leaked?
> Should there be a whitish discoloration inside the tube?
> I will check mine later next month. Right now my amp stuff in under 4 feet of snow here in western Ontario.
> Karel, VA3KO
> 
> ----- Original Message ----- From: "Carl" <km1h at jeremy.mv.com>
> To: "Karel" <kebenstr at bmts.com>; <amps at contesting.com>
> Sent: Monday, January 27, 2014 9:17 PM
> Subject: Re: [Amps] Tube swap
> 
> 
>> People are still running HB 4X1 amps and others continue to build when the tubes have been on hand for ages or can be found cheap.
>> 
>> The big problem, even with NIB, is the seals leak and the tube slowly goes to air.
>> 
>> Carl
>> KM1H
>> 
>> 
>> ----- Original Message ----- From: "Karel" <kebenstr at bmts.com>
>> To: "Hardy Landskov" <n7rt at cox.net>; "Fuqua, Bill L" <wlfuqu00 at uky.edu>; "Jack Taylor" <jack at n7oo.com>; <amps at contesting.com>
>> Sent: Monday, January 27, 2014 8:08 PM
>> Subject: Re: [Amps] Tube swap
>> 
>> 
>>> I still have 5 tubes, 4-1000A, 2 of them never used, 3 used ones, is there still demand for these?
>>> I started an amp (2 tubes). So far I did not finish the project yet, not sure if I will. Perhaps if I go with 1 tube only.
>>> Karel Ebenstreit, VA3KO
>>> 
>>> ----- Original Message ----- From: "Hardy Landskov" <n7rt at cox.net>
>>> To: "Fuqua, Bill L" <wlfuqu00 at uky.edu>; "Jack Taylor" <jack at n7oo.com>; <amps at contesting.com>
>>> Sent: Monday, January 27, 2014 5:58 PM
>>> Subject: Re: [Amps] Tube swap
>>> 
>>> 
>>>> In addition to Bill's list, it will take about 30 to 40% more drive. Been there, done that.
>>>> GL Hardy N7RT
>>>> 
>>>> 
>>>> ----- Original Message ----- From: "Fuqua, Bill L" <wlfuqu00 at uky.edu>
>>>> To: "Jack Taylor" <jack at n7oo.com>; <amps at contesting.com>
>>>> Sent: Monday, January 27, 2014 1:57 PM
>>>> Subject: Re: [Amps] Tube swap
>>>> 
>>>> 
>>>>>   Yes and no.
>>>>> 1. The 4-1000A is taller so the chimney may not fit.
>>>>> 2. The 4-1000A in grounded grid will require more plate voltage to achieve the same output.
>>>>> 3. The input impedance of the 4-1000a is a bit higher so you may have to make some changes to your input matching ckt.
>>>>> 4.  The control grid pin needs to be grounded as well as screen grid pins.
>>>>> 5.  The output Z of the 4-1000A is higher but not so much that most plate tank circuits can't deal with it.
>>>>> 73
>>>>> Bill wa4lav
>>>>> 
>>>>> ________________________________________
>>>>> From: Amps [amps-bounces at contesting.com] on behalf of Jack Taylor [jack at n7oo.com]
>>>>> Sent: Monday, January 27, 2014 3:51 PM
>>>>> To: amps at contesting.com
>>>>> Subject: [Amps] Tube swap
>>>>> 
>>>>> Am in the process of bringing back to life a RF 102A.  Should the 3-1000Z
>>>>> turn out to be defective, can I directly
>>>>> interchange it with a 4-1000A?
>>>>> 
>>>>> Jack - n7oo
>>>>> 
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>>>> 
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