Phil Clements wrote:
> >The only questions are: how much less good, and does it matter?
>>That's why I was looking for separate evidence whether the color of the
>>markings is dependent on the orientation of the tube.
>
>You are just going to have to trust us on this until you see measurements for
>yourself.
I do indeed trust you, Phil - that's exactly why I was asking about
this.
>The Heath designers did not just get up one morning, place a fan
>from the parts room in front of a pair of 3-500Z's and start shipping kits.
>Rich
>and others have explained the brilliant engineering scheme in the SB series
>amplifiers...I will not repeat it.
>
Yes, I've seen Rich's article, and there's absolutely no doubt that (a)
the SB-220 cooling system was very carefully thought out, and certainly
no lucky fluke; and (b) it works.
>Suffice to say that the entire tube envelope gets cooled with this method.
>There are no "hot spots" or "eddy voids" to worry about.
There is clearly *enough* cooling all around the tube, but that still
doesn't mean the cooling is *equal* all around.
>I don't use the
>blowing out of the candle example. I like the example that I prove every
>time I dry my hair...place the dryer so it aims directly on your Adam's apple.
>The hair on the back of your neck will dry just as fast as if you had gone
>into contortions and aimed the dryer directly on the hair.
>
It's a long time since I had any use for a hair-dryer! OK, I'll try it -
but only after our Belgian visitors leave. Wouldn't want them to get any
strange impressions...
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.com/g3sek
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