[AMPS] Sucking instead of Blowing (was - This guy is gotta be kidding!)

[2]

>
>2 wrote:
>>>Unfortunately that isn't at all relevant to forced-air cooling, where
>>>the airflow is very turbulent and the flow pattern is quite different. 
>>>
>>’Ǩ  fasten seatbelts
>>
>>>Air is blasted at the upstream side of the tube, cooling it well, but
>>>the flow breaks away from the surface half-way around to form a
>>>turbulent wake. 
>>
>>۬  Not with the quiet, slow speed fan in a SB-220, Ian..
>>
>All practical cooling fans create turbulence. It's easy to check with a
>streamer of smoke.

€  If there was much turbulence in the SB-220, then the 3-500Z marking 
ink would turn brown on the downwind side.  However, the observed ink 
color does not change with use -- unless the owner fails to oil the fan 
motor bearings, and the motor eventually siezes and stops turning.  

>>>The downstream side is only cooled by eddies in the
>>>wake, and there may even be negative pressure on the opposite side. 
>>>
>>>There is absolutely no doubt that cooling is less good on the downstream
>>>side. 
>>
>>’Ǩ  The  colour of the ink on the 3-500Z glass does not indicate this. 
>>
>Thank you - that's the information I was asking for. Can you confirm
>that the ink is on the opposite side from the fan?
>
€  I checked a 3-500z in my workshop, date-coded 8350.  The ink was 
nearest to pin 4  --  whiich is the downwind/leeward side in the V2 
socket.  However I recall using tubes whose marking ink was elsewhere.  

>> >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.
>>>
>>’Ǩ  Denial of reality - the greatest glitch in the human psyche. Alas. 
>
>How very true for all of us. That's why I was asking for simple
>information about what the reality IS, in the SB-220 and the L4-B.
>
€  The L4-B reportedly uses air-system (vertical flow)cooling.  The 
TL-922, the SB-220 and the Drake L7 use horizontal flow cooling.  

later,  Ian 

-  R. L. Measures, 805.386.3734, www.vcnet.com/measures.  
end


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