[Amps] Heat Measurement in Amps

[Jeff Blaine AC0C]

In addition to what Bill is suggesting, depending on accessibility to the 
tube, you may be able to use an IR thermometer to look at the tube that way. 
These things are pretty cheap now and while you can't use them full-time, 
for looking at the worst case (5 min into a RTTY transmission), it would 
give you an idea of what the tube temps look like assuming the tube lends 
itself to that kind of measurement.

Going by the exhaust temp does not really help you to know what the tube 
seals and body are feeling unfortunately.   However, if you are using the 
tube within it's operating envelope (easy to figure out with Eimac, or 
others with proper data sheets - more difficult with the Russian tubes 
though) and have the required amount of air volume pumping, you can assume 
these temps are not being violated.

73/jeff/ac0c


--------------------------------------------------
From: "Bill, W6WRT" <dezrat1242 at yahoo.com>
Sent: Saturday, June 12, 2010 6:39 AM
To: <amps at contesting.com>
Subject: Re: [Amps] Heat Measurement in Amps

> ORIGINAL MESSAGE:
>
> On Thu, 10 Jun 2010 11:07:37 -0700, Patrick Barthelow
> <apolloeme at live.com> wrote:
>
>>
>>Has anyone found a decent cheap temperature sensor/guage  (perhaps even at 
>>harbor freight, etc) that you could place at a specified location in the 
>>exhaust airstream of the tubes, of various amps to see and record what is 
>>"normal" temp ranges?  Maybe the brain trust here, could search out a 
>>standard, cheap temp measurement sensor  (some DVMs have them) and do some 
>>testing and publishing of expected exhaust air temps of various amps in 
>>various modes, like Low duty cycle (SSB), medium (CW) or high (RTTY)
>
> REPLY:
>
> For low cost, it would be hard to beat a cook's meat thermometer,
> available at any grocery store. I have one sitting on top of my amp as
> I speak. It has a long probe, so I simply drilled a hole through a
> small piece of wood and poked the probe through, leaving it sticking
> out about two inches. In normal RTTY operation it rarely reads over
> about 150 degrees F. Being non-electronic, they are immune to RF.
> Works great.
>
> A related idea, which I never got around to implementing, is to
> install a small thermal switch connected to an alarm of some kind.
> These are cheap and available in a wide range of temperatures. Also
> non-electronic. Pretty sure Mc-Master Carr carries them.
>
> 73, Bill W6WRT
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