[Amps] New High Efficiency 3-500Z plate caps

[Carl]

>
>
> On 7/1/2010 3:43 PM, John E. Cleeve wrote:
>> Gentlemen,
>>
>>
>>
>> I cannot get to my stock of Eimac 3-500 glass chimneys at present, but I
>> recall, the Eimac drawing of the 3-500 glass chimney shows that the top 
>> edge
>> of the chimney is formed into a pronounced inward lip of about a quarter 
>> of
>> an inch, or more,
> IIRC the ones that were in my 2K4 were notably more.
>>   in width, which directs the emerging air flow coming up
>> the chimney from around the side of the tube, over and across the top of 
>> the
>> 3-500 and directed so as to cool the glass/metal seal of the anode cap
>> connection. The "finned" top cap was, or still is, the one shown in most
>> published designs for 3-500 amplifiers....73,
> It may be, but it's in an area of null horizontal flow and the directed
> air is coming in from all sides where it is deflected upwards.
> Also the heat conducted to the Aluminum is limited by the material and
> size of the plate conductor that exits through the glass.
>
> As some one has already mentioned, the sole purpose of the Aluminum
> radiator is to help keep the seal temperature down.
>
> 73
>
> Roger (K8RI)
>>   John G3JVC / GM3JVC.


The Eimac SK-406 chimney is indeed curved inward at the top; the aftermarket 
version used on many commercial amps is straight sided. This probably leads 
to confusion among those who arent familiar with both versions.

Carl
KM1H