[Amps] Centurion cooling improvement ideas for AM service

[R.Measures]

On Aug 26, 2004, at 4:20 AM, Jason Buchanan wrote:

> R.Measures wrote:
>
>> Ian -- Agreed, however, the solution is:   do not have the dull-gray 
>> anode stem chrome-plated on the 3-500Z.
>
>
> Is there any benefit to using heat dissipators with 
> larger/taller/wider/more fins?

  For vertical airflow, wider is better since only the bottom fin gets 
much air.  With vertical air flow, one wide and thick horizontal fin 
would be optimal  With horizontal airflow and horizontal fins, the 
total surface area of the fins is the bottom-line.  .

> I've seen ads for anode coolers that were an inch tall...  similar to 
> those in QROtec amps... 
> http://www.hamradiomarket.com/Articles/QRO-Images/60.JPG

RE:  the photo:  Horizontal fins with horizontal cooling makes good 
sense, however, to adequately cool a 3-500Z with one fan, the fan must 
be larger than at least 150mm -- which the fan in the photo obviously 
is not.  (the Heath SB-220 uses a 150mm fan).  The nearest size 
DC-brushless fan that is adequate for cooling 3-500Zs is 172mm.  Papst 
makes one which sells for c. $50.  2-tubes cost $298.  However, if a 
split chassis is not utilized, the fan shown in the photo can be used 
to cool things above the chassis, and a 50mm fan can be used below the 
chassis to cool the filament pins, provided that pin #s 1 and 5 face 
each other on the adjacent tube sockets.  .
>
> The Centurion has anode caps that are two fins instead of 5....
>
>
> 73 Jason N1SU
>
>
Richard L. Measures, AG6K, 805.386.3734.  www.somis.org