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Re: [Amps] Alpha vs Henry

To: "Jeff Blaine" <keepwalking188@yahoo.com>, <amps@contesting.com>
Subject: Re: [Amps] Alpha vs Henry
From: "Carl" <km1h@jeremy.mv.com>
Date: Thu, 7 Apr 2011 13:32:48 -0400
List-post: <amps@contesting.com">mailto:amps@contesting.com>
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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>  >> Amps@contesting.com
>  >> http://lists.contesting.com/mailman/listinfo/amps
>  >
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>
>
>
> -- 
> Damon Stewart, KJ7E
> 

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