Date: Thu, 1 Jul 2010 20:06:59 -0700
From: Jim W7RY <jimw7ry@gmail.com>
Subject: Re: [Amps] New High Efficiency 3-500Z plate caps
You'll also notice the crayon is going DIRECTLY onto the anode "pin" the
tube on the right. And on the TOP of the "new fangled" plate cap on the
right.
Not a very fair test. I would like to see the test repeated with a GENUINE
HR-6 and the "new fangled" plate cap.
## the Eimac set up used a Eimac chimney + HR-6 anode connector.
On a 4-1000 Eimac chimney... it's 6" ID at the base.. and only 3" ID
at the top. The Eimac chimney for the 3-500 was similar, [smaller
ID at top]. Eimac's HR-6/8 anode connector's never made any sense to me.
They are designed for transverse cooling..with Horz fins.. yet with a chimney
and squirel cage blower.. air comes straight up ! They should have made the
fins vertical ....[for use with chimney's]
## IF you really want to suck the heat away....fast, the anode connector's
should be made from CU..and not AL. CU conducts heat almost twice as fast
as AL. All this heat has to ultimately be transfered to the surrounding air.
A lot more thinner fins [ either horz or vert] will work better than fewer,
thicker fins.
## If you look down from above, on a 3x3 metal triode,sitting on a sheet of
white paper,
with a light on the paper, you will see the fins inside are paper thin.. and
lot's of them.
They are all folded back on themselves on the outer periphery too. The big,
thick fins
at the top and bottom of the big metal tubes are actually ..'struts'...
designed to support
the vertcial cylinder that surrounds the actual inner anode fins. The
fins/struts on the
metal tubes are silver plated copper.
## The vertical anode cooler fins on the L4B are designed with a slight
downward slope,
to minimize stray C to any top lid.
## yes, I'd like to see the test re-run... with the new fangled cooler vs an
Eimac HR-6.
The HR-6 may well be way too high for a lot of 3-500Z amps.. and add a lot of
stray C to the
top lid. A better design for transverse cooling would be low profile, big
diam, super thin
fins... made from CU.. then silver plated.
## back in 1970.. a buddy across town made his own version of HR-8's by
cutting fins
into solid AL cylinders .... in a lathe. It was pretty easy to do. Then the
bottom was drilled out
to take the big anode pin on the tube. A smaller tapped hole on very top for
the strap.
One more tapped hole on the lower side to lock it to the anode itself..same as
a HR-8. This
was back in the days when everything got home brewed.
Later... Jim VE7RF
73
Jim W7RY
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