[Hammarlund] Hammarlund Digest, Vol 129, Issue 7

Sat Oct 4 21:01:48 EDT 2014

I do not think I saved any of them , I have seen horizontal output tubes 
that have been so hot the glass softened and the outside air pressure pushed 
the envelope in at that spot making a neat little cone that may or may not 
be open to the outside . most of them I saw were open to the outside air .

andrew
kd5pnt
----- Original Message ----- 
From: <hammarlund-request at mailman.qth.net>
To: <hammarlund at mailman.qth.net>
Sent: Saturday, October 04, 2014 7:36 PM
Subject: Hammarlund Digest, Vol 129, Issue 7

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> Today's Topics:
>
>   1. Re: Speaking of Tubes ...(Small Tubes) (kirklandb at sympatico.ca)
>   2. Re: Unknown tubes and WW2 military secrets (k9cox at charter.net)
>   3. Re: Need HQ-189 replacement BFO variable capacitor (Al Parker)
>   4. SP-600 JX-17 with case (Bob Young)
>   5. Re: Tube shields and heat (Robert Moses)
>   6. Re: Tube shields and heat (Bob Camp)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Thu, 2 Oct 2014 13:28:40 +0000
> From: <kirklandb at sympatico.ca>
> To: Hammarlund QTH LIST <hammarlund at mailman.qth.net>
> Subject: Re: [Hammarlund] Speaking of Tubes ...(Small Tubes)
> Message-ID: <BLU173-W511F58D1C0BDACDCCDB78FCFB90 at phx.gbl>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Check out "Russian Rod Tubes" on google.
>
>
>>
>> On Tuesday, September 30, 2014, Kenneth G. Gordon 
>> <kgordon2006 at frontier.com>
>> wrote:
>> > On 30 Sep 2014 at 22:55, Guido Santacana wrote:
>> >
>> >> What if... Solid state devices had not been invented back in the 50s.
>> Tubes
>> >> would have evolved into ....... Sub sub miniature tubes?
>> >
>> > Probably.
>> >
>> > I have always regarded the subminiature tubes first developed during 
>> > WWII,
>> > as an extreme example of what COULD be done with tubes.
>> >
>
>
>
> ------------------------------
>
> Message: 2
> Date: Thu, 2 Oct 2014 13:38:34 +0000
> From: <k9cox at charter.net>
> To: "=?utf-8?Q?hammarlund at mailman.qth.net?="
> <hammarlund at mailman.qth.net>
> Subject: Re: [Hammarlund] Unknown tubes and WW2 military secrets
> Message-ID: <yDgN1o00K0k9ncc01DgPTV at charter.net>
> Content-Type: text/plain; charset="utf-8"
>
> https://www.youtube.com/watch?v=6-D592VR4RU
>
>
>
>
>
>
> Sent from Windows Mail
>
> ------------------------------
>
> Message: 3
> Date: Thu, 02 Oct 2014 09:57:10 -0400
> From: Al Parker <anchor at ec.rr.com>
> To: "Peter R. Zidek" <zidek at charter.net>, hammarlund at mailman.qth.net
> Subject: Re: [Hammarlund] Need HQ-189 replacement BFO variable
> capacitor
> Message-ID: <542D59B6.9000002 at ec.rr.com>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> Hi Peter,
> I can't get into my HQ-170 right now to look, but if you can send me a
> pic and measurements, I'll see what I can find.  I have quite a few
> small variables.
> 73,
>
> Al, W8UT
> www.boatanchors.org
> www.hammarlund.info
>
> "There is nothing -- absolutely nothing -- half so much
> worth doing as simply messing about in boats"
> Ratty, to Mole
>
> On 10/1/2014 10:07 PM, Peter R. Zidek wrote:
>> Hi everyone
>>
>> ,
>>
>> I'm in the process of restoring a decent condition HQ-170
>>
>> Everything seems to work but the BFO circuit because of a
>> tuning BFO cap that fell apart.
>>
>> Does anyone have a spare HQ-170 Variable BFO capacitor from
>> a junker HQ-170 or know of a
>>
>> source for a replacement.
>>
>>
>>
>> Peter Zidek
>>
>> ______________________________________________________________
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>>
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>
> ------------------------------
>
> Message: 4
> Date: Sat, 4 Oct 2014 00:04:26 -0400
> From: Bob Young <bobyoung53 at hotmail.com>
> To: "hammarlund at mailman.qth.net" <hammarlund at mailman.qth.net>
> Subject: [Hammarlund] SP-600 JX-17 with case
> Message-ID: <BLU177-W278D2EE86328AE0BE35E24CCA70 at phx.gbl>
> Content-Type: text/plain; charset="iso-8859-1"
>
> 135.00 BIN ebay: grab it now
>
> 191358079680
>
> Not a looker but can't beat the price.
>
>
> Bob Young
> KB1OKL
>
>
> ------------------------------
>
> Message: 5
> Date: Sat, 04 Oct 2014 18:00:17 -0600
> From: Robert Moses <rhmoses at earthlink.net>
> To: hammarlund at mailman.qth.net
> Subject: Re: [Hammarlund] Tube shields and heat
> Message-ID: <54308A11.4010805 at earthlink.net>
> Content-Type: text/plain; charset=windows-1252
>
> The rate at which chemical reactions such as those involved in the
> degradation of tubes takes place increases 2.3 times for each 10 degree
> C increase in temperature. Cooler is always better as long as it is warm
> enough to work.
>
> On 09/27/2014 12:54 PM, Kenneth G. Gordon wrote:
>> On 27 Sep 2014 at 13:31, Guido Santacana wrote:
>>
>>> As for tube shields, if they are not IERC shields, paint will not do 
>>> much.
>> Guido: on the basis of experiment, FLAT black painted tube shields 
>> reduces
>> the heat in the tube by 17%, so yes, it does do something worthwhile. For
>> instance, reducing the heat of 300 degrees to 249 degrees, or -51 
>> degrees.
>>
>> You may not think this is worthwhile, but I do.
>>
>> According to my reading on the subject, reducing tube heat by even 1 
>> degree
>> contributes significantly to longer tube life.
>>
>>> Better to leave the tubes uncovered and use the fan.
>> True.
>>
>> Ken W7EKB
>> ______________________________________________________________
>> Hammarlund mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/hammarlund
>> Help: http://mailman.qth.net/mmfaq.htm
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>>
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>> ** For Assistance: dfischer at usol.com **
>>
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
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>
>
>
> ------------------------------
>
> Message: 6
> Date: Sat, 4 Oct 2014 20:36:48 -0400
> From: Bob Camp <kb8tq at n1k.org>
> To: Hammarlund QTH LIST <hammarlund at mailman.qth.net>
> Subject: Re: [Hammarlund] Tube shields and heat
> Message-ID: <D2BD3C93-F767-4EAD-8166-59791378F888 at n1k.org>
> Content-Type: text/plain; charset=windows-1252
>
> Hi
>
> Chemical rate law phenomenon are one of many things that cause degradation 
> in a device. The rate law is true once you reach an activation energy 
> level. For many of the materials in a tube that occurs in the > 1,000 C 
> range. Yes a lot depends on exactly which reaction you are tracking on 
> each material.
>
> Cooling the outside of the tube does little for things like the filament. 
> It?s going to be at ?glow? temperature regardless of what you do on the 
> outer envelope. The grid to cathode spacing for a tube to work is such 
> that the control grid will pretty much follow the cathode, regardless of 
> what you do to the plate. The only thing you may be cooling with a black 
> shield is the plate and to a lesser degree the suppressor grid (if it?s a 
> pentode).  I have never seen a tube fail for glass envelope degradation 
> due to temperature. Dropping them does not count in this case. Doubling 
> the life of the glass envelope, when it never falls regardless does little 
> to ?improve? the tube. Glass to metal seal temperates are a different 
> issue, they are little impacted by a tube shield.
>
> Since you depend on heat to activate the getter material, and it?s on the 
> tube shell, cooling the shell may actually degrade the reliability if it?s 
> taken to far.
>
> ???????????????
>
> Why do most tubes fail?
>
> 1) The filament / cathode system runs out of coating / electron radiation 
> capability. It stops glowing, at least in terms of electrons.
>
> 2) The envelope fills with gas, but that does not poison the filament. 
> This happens when a glass to metal seal fails.
>
> 3) A weld breaks and the tube just goes dead. Normally this is due to 
> cycling the tube. Welds are a ?high activation energy? item.
>
> 4) A grid slumps and it shorts to another element in the tube
>
> At least of the few 10?s of thousands of tubes I?ve seen, number one wins 
> out by far. That one is not impacted by cooling at all. Numbers 2 and 3 
> depend a lot on what sort of tube it is. They happen more often than 
> number 4 by far. I have yet to see a receiving tube with a hole burned in 
> the plate. Maybe it happens, if it does, it?s rare (so it?s not on the 
> list).
>
> Cooling the tube isn?t going to impact 1 or 2 (the big ones) at all. It 
> may impact 3 depending on the location of the weld. It certainly would 
> impact 4 on the suppressor (but not the cathode or control grid). Holes 
> burning in the plate are the big one that cooling would help. Since you 
> aren?t addressing the main wear out mechanisms, cooling isn?t worth it.
>
> Bob
>
> On Oct 4, 2014, at 8:00 PM, Robert Moses <rhmoses at earthlink.net> wrote:
>
>> The rate at which chemical reactions such as those involved in the
>> degradation of tubes takes place increases 2.3 times for each 10 degree
>> C increase in temperature. Cooler is always better as long as it is warm
>> enough to work.
>>
>> On 09/27/2014 12:54 PM, Kenneth G. Gordon wrote:
>>> On 27 Sep 2014 at 13:31, Guido Santacana wrote:
>>>
>>>> As for tube shields, if they are not IERC shields, paint will not do 
>>>> much.
>>> Guido: on the basis of experiment, FLAT black painted tube shields 
>>> reduces
>>> the heat in the tube by 17%, so yes, it does do something worthwhile. 
>>> For
>>> instance, reducing the heat of 300 degrees to 249 degrees, or -51 
>>> degrees.
>>>
>>> You may not think this is worthwhile, but I do.
>>>
>>> According to my reading on the subject, reducing tube heat by even 1 
>>> degree
>>> contributes significantly to longer tube life.
>>>
>>>> Better to leave the tubes uncovered and use the fan.
>>> True.
>>>
>>> Ken W7EKB
>>> ______________________________________________________________
>>> Hammarlund mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/hammarlund
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Hammarlund at mailman.qth.net
>>>
>>> List Administrator: Duane Fischer, W8DBF
>>> ** For Assistance: dfischer at usol.com **
>>>
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>>
>>
>> ______________________________________________________________
>> Hammarlund mailing list
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>> ** For Assistance: dfischer at usol.com **
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>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
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>
> End of Hammarlund Digest, Vol 129, Issue 7
> ******************************************
> 