On 04/08/2011 06:52 AM, Gary Schafer wrote:
> With IR how do you know if you are measuring actual tube envelope glass/seal
> temp or the radiated heat itself?
> Same when measuring exterior anode tubes. Are you seeing the tube structure
> or the hot air coming out?
> Probably a little easier on the exterior anode tube as you can move the IR
> thermometer window down away from the air flow some.
>
> 73
> Gary K4FMX
>
>> -----Original Message-----
>> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]
>> On Behalf Of Carl
>> Sent: Thursday, April 07, 2011 7:07 PM
>> To: Barrie Smith; amps@contesting.com
>> Subject: Re: [Amps] Alpha vs Henry
>>
>> Inaccurate in the sense that its just a ballpark indicator.
>>
>> I like the IR method since it tells me the glowing 304TL's are not
>> really
>> going to melt!
>>
>> It also told me that I can use a smaller and slower blower on the
>> 3CX1000A7
>> 2M amp, the one Ive been using for 25+ years is probably fine for a YC-
>> 156!
>>
>> Carl
>> KM1H
>>
>>
>> ----- Original Message -----
>> From: "Barrie Smith"<barrie@centric.net>
>> To: "Carl"<km1h@jeremy.mv.com>;<amps@contesting.com>
>> Sent: Thursday, April 07, 2011 6:15 PM
>> Subject: Re: [Amps] Alpha vs Henry
>>
>>
>>>
>>>> Ancient and inaccurate tech, even I moved into the 21st century!
>>>>
>>>> Carl
>>>> KM1H
>>> Well, since I first used Templestick in the 1950s, I knew it was
>> ancient,
>>> but I didn't know it was inaccurate.
>>>
>>> What with all that "Heavy Metal" in your shack you'd be hard-pressed
>> to
>>> prove you've moved into the 21ST century!
>>>
>>> 73, Barrie, W7ALW
>>>>
>>>> ----- Original Message -----
>>>> From: "Barrie Smith"<barrie@centric.net>
>>>> To:<amps@contesting.com>
>>>> Sent: Thursday, April 07, 2011 3:13 PM
>>>> Subject: Re: [Amps] Alpha vs Henry
>>>>
>>>>
>>>> Why not just use Templestick?
>>>>
>>>> 73, Barrie, W7ALW
>>>>
>>>> ----- Original Message -----
>>>> From: "Carl"<km1h@jeremy.mv.com>
>>>> To: "Jeff Blaine"<keepwalking188@yahoo.com>;<amps@contesting.com>
>>>> Sent: Thursday, April 07, 2011 10:32 AM
>>>> Subject: Re: [Amps] Alpha vs Henry
>>>>
>>>>
>>>> Not as fast as the speed of light, it takes 2 handed coordination(-;
>> Or
>>>> 2
>>>> people if you also want to immediately kill amp power, take the shot
>> and
>>>> then power up again for normal cooldown.
>>>>
>>>> Carl
>>>> KM1H
>>>>
>>>>
>>>> ----- Original Message -----
>>>> From: "Jeff Blaine"<keepwalking188@yahoo.com>
>>>> To: "Carl"<km1h@jeremy.mv.com>;<amps@contesting.com>
>>>> Sent: Thursday, April 07, 2011 12:56 PM
>>>> Subject: Re: [Amps] Alpha vs Henry
>>>>
>>>>
>>>>> Carl,
>>>>>
>>>>> You are right on the affected reading.
>>>>>
>>>>> On the couple of IR guns that I have, they seem to be affected by
>> some
>>>>> frequencies more than others. So I try to check it while the
>>>>> rf is rocking by picking a different band.
>>>>>
>>>>> The problem I see with the key-up measurement is that, with an
>> efficient
>>>>> cooling, the change in temp vs. time is very fast. So you
>>>>> are left to interpolate the slope of the temp drop and estimate the
>> peak
>>>>> anode temps to an extent.
>>>>>
>>>>> 73, Jeff ACØC
>>>>> www.ac0c.com
>>>>>
>>>>> -----Original Message-----
>>>>> From: Carl
>>>>> Sent: Thursday, April 07, 2011 9:16 AM
>>>>> To: Jeff Blaine ; amps@contesting.com
>>>>> Subject: Re: [Amps] Alpha vs Henry
>>>>>
>>>>> I was referring to an IR gun for actual anode temp. Do it right
>> after
>>>>> key
>>>>> up
>>>>> as RF has a tendency to affect the gun.
>>>>>
>>>>> You may be surprised at how cool the anodes are often run. Another
>> thing
>>>>> to
>>>>> look at is the color of the anode and the fins; if they are not
>>>>> discolored
>>>>> you havent reach anywhere near the danger point yet.
>>>>>
>>>>> Ive had many tubes of the 8874, 8122, 8877, 3CX800 variety, and
>> others,
>>>>> come
>>>>> thru here that are severely heat discolored yet are perfectly fine.
>>>>>
>>>>> Carl
>>>>> KM1H
>>>>>
>>>>>
>>>>> ----- Original Message -----
>>>>> From: "Jeff Blaine"<keepwalking188@yahoo.com>
>>>>> To: "damon stewart"<wsmc551@gmail.com>
>>>>> Cc: "Carl"<km1h@jeremy.mv.com>; "Al Kozakiewicz"
>>>>> <akozak@hourglass.com>;
>>>>> <amps@contesting.com>
>>>>> Sent: Wednesday, April 06, 2011 9:55 PM
>>>>> Subject: Re: [Amps] Alpha vs Henry
>>>>>
>>>>>
>>>>> Sorry Damon to confuse.
>>>>>
>>>>> The exhaust temp is only good for determining how long it takes the
>>>>> tube/exhaust to get up to a steady temp. The actual temp around the
>>>>> tube
>>>>> cannot be easily deduced from this, as far as I can tell although I
>>>>> think
>>>>> it
>>>>> should be in theory.
>>>>>
>>>>> A decent but not perfect solution is measuring the anode temp with
>> an IR
>>>>> gun
>>>>> at the end of a run just prior to key up. And that will be much
>> higher
>>>>> than
>>>>> the exhaust temp.
>>>>>
>>>>> 73, Jeff ACØC
>>>>> www.ac0c.com
>>>>>
>>>>>
>>>>>
>>>>> From: damon stewart
>>>>> Sent: Wednesday, April 06, 2011 8:41 PM
>>>>> To: Jeff Blaine
>>>>> Cc: Carl ; Al Kozakiewicz ; amps@contesting.com
>>>>> Subject: Re: [Amps] Alpha vs Henry
>>>>>
>>>>> You dont want the exhaust temp to get anywhere close to the seal
>> temp!
>>>>> By that point your seal temp is way past the limit. On an 8877 the
>> seal
>>>>> temp is rated at 250 deg C max (480 deg F). Id try to keep the
>> exhaust
>>>>> temp below 300 deg F.
>>>>>
>>>>>
>>>>>
>>>>> On Wed, Apr 6, 2011 at 6:33 PM, Jeff Blaine
>> <keepwalking188@yahoo.com>
>>>>> wrote:
>>>>>
>>>>> RTTY contest duty is the worst for the transformer - not for the
>> tube.
>>>>> The thermal mass of the transformer is huge and if it starts out
>> with a
>>>>> low temp the gradient will keep the innermost windings from
>>>>> heating to max in RTTY service until you've been running for an
>> hour or
>>>>> so. And as the guys mentioned earlier, any air circulation
>>>>> on the transformer (even really minimal levels) will have a huge
>> impact
>>>>> on
>>>>> the final temps the tx reaches.
>>>>>
>>>>> If you want to whack the tube, a good 5 minute RTTY transmission is
>> the
>>>>> way to go. The tube heats up to it's max after maybe 15-30
>>>>> seconds - just stick a probe and watch the exhaust temps stop
>> rising at
>>>>> some point the system is stable and if you have not pushed
>>>>> pass the tube op temps (seal limited) then it's probably going to
>> be
>>>>> fine.
>>>>>
>>>>> 73, Jeff ACØC
>>>>> www.ac0c.com
>>>>>
>>>>> -----Original Message-----
>>>>> From: Carl
>>>>> Sent: Wednesday, April 06, 2011 7:44 PM
>>>>> To: Al Kozakiewicz ; amps@contesting.com
>>>>> Subject: Re: [Amps] Alpha vs Henry
>>>>>
>>>>> Maybe time to see what the anode temperature is but Id think 1000W
>> out
>>>>> would
>>>>> be fine.
>>>>>
>>>>> Carl
>>>>> KM1H
>>>>>
>>>>>
>>>>> ----- Original Message -----
>>>>> From: "Al Kozakiewicz"<akozak@hourglass.com>
>>>>> To:<amps@contesting.com>
>>>>> Sent: Wednesday, April 06, 2011 8:35 PM
>>>>> Subject: Re: [Amps] Alpha vs Henry
>>>>>
>>>>>
>>>>> > 1500 watts continuous for 30 minutes; 2500 for 30 seconds.
>>>>> >
>>>>> > Even if I do nothing but call CQ every 2 seconds, that's probably
>>>>> "only"
>>>>> > about a 60% duty cycle. I'm just trying to get a feel for how
>> much
>>>>> > derating is prudent when using the thing for extended periods of
>>>>> time.
>>>>> >
>>>>> > 73
>>>>> >
>>>>> > Al
>>>>> > AB2ZY
>>>>> >
>>>>> > -----Original Message-----
>>>>> > From: Carl [mailto:km1h@jeremy.mv.com]
>>>>> > Sent: Wednesday, April 06, 2011 5:37 PM
>>>>> > To: Al Kozakiewicz; amps@contesting.com
>>>>> > Subject: Re: [Amps] Alpha vs Henry
>>>>> >
>>>>> > What does Ameritron say?
>>>>> >
>>>>> > Carl
>>>>> > KM1H
>>>>> >
>>>>> >
>>>>> > ----- Original Message -----
>>>>> > From: "Al Kozakiewicz"<akozak@hourglass.com>
>>>>> > To:<amps@contesting.com>
>>>>> > Sent: Wednesday, April 06, 2011 5:05 PM
>>>>> > Subject: Re: [Amps] Alpha vs Henry
>>>>> >
>>>>> >
>>>>> >> Can anyone tell me how much power an AL-1500 is rated to produce
>> at
>>>>> a
>>>>> >> 100%
>>>>> >> duty cycle?
>>>>> >>
>>>>> >> During RTTY contests and outputting about 1000 watts, the tube
>> side
>>>>> of
>>>>> >> the
>>>>> >> cabinet gets mighty warm. The power supply side seems cool -
>> but
>>>>> then,
>>>>> >> that's with the cover on. I don't know how hot is too hot and
>> it
>>>>> would
>>>>> >> be
>>>>> >> useful to know at least how much continuous power the supply is
>>>>> rated
>>>>> >> for.
>>>>> >>
>>>>> >> Tube cooling is probably another issue...
>>>>> >>
>>>>> >> Al
>>>>> >> AB2ZY
>>>>> >> _______________________________________________
>>>>> >> 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
>>>>>
>>>>> _______________________________________________
>>>>> Amps mailing list
>>>>> Amps@contesting.com
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>>>>>
>>>>> _______________________________________________
>>>>> Amps mailing list
>>>>> Amps@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Damon Stewart, KJ7E
>>>>>
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>>>>
>>>>
>>>>
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>>>
>>>
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You could test the accuracy of the IR gun method if you have a spare
tube. Put the spare tube and some other control material in the oven at
say 300 deg for a half hour and check it with the IR gun. At least you
will know if the IR gun is able to read the true temp of the tube,
especially for silver plated external anodes.
Damon Stewart, KJ7E
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