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Re: [Amps] Alpha vs Henry

To: "Barrie Smith" <barrie@centric.net>, <amps@contesting.com>
Subject: Re: [Amps] Alpha vs Henry
From: "Carl" <km1h@jeremy.mv.com>
Date: Thu, 7 Apr 2011 19:06:51 -0400
List-post: <amps@contesting.com">mailto:amps@contesting.com>
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
>>>  >> _______________________________________________
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>>>  >
>>>  > _______________________________________________
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>>>
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>>>
>>>
>>>
>>> -- 
>>> Damon Stewart, KJ7E
>>>
>>
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