That is a good point for tubes like the YC-156/179. On tubes like the planar constructed GS-35B, the grid is tied directly to the ring and can move more heat. Unfortunately, the actual construction of the grid itself may actually be the limiting factor on the GS-35.
73, Tony W4ZT
craxd wrote:
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Jim,
What you describe may help a little. The problem is the internal connection from the ring to the grid itself, and it's size. If it's only a piece of wire, you may not gain anything as the wire would be the bottleneck I would think. The ring would help a little by being a larger heatsink for the connection itself, but the grid itself is still wire which it's size and coating (gold, etc) can only take so much current. The ring would have to dissapate the heat from the grid via the internal connection(s).
Best,
Will
From: ham_amplifiers@... [mailto:ham_amplifiers@yahoogroups.
com]
On Behalf Of pentalab
Sent: Donnerstag, 21. September 2006 22:12
To: ham_amplifiers@...
Subject: [ham_amplifiers] Re: Can Grid Dissipation in metal GG triodes be
increased ????
--- In ham_amplifiers@ <mailto:ham_amplifiers%40yahoogroups.com>
yahoogroups.com, "pentalab" <jim.thomson@> wrote:
Gents
On these 3CX-6000's and also the socketless version [ YC-
243],
I fool with from time to time, Eimac/ Svetlana state's the
grid
diss at 225 Watts CCS. [3CX-3000A7 is also 225 w CCS grid]
Now, since the tube(s) can be operated in either GG OR grid driven.... it occured to me that in grid driven mode... the grid should still has a 225 w CCS rating ???
The point here is..... in GG service... you bolt this huge grid ring to the chassis.... and in the case of the socketless version.... an even bigger diam grid flange is bolted to the chassis !
Now... that alone should heatsink the grid ??? Since the
grid
is sitting in a vac... the only way for thermal heat to escape is via the grid flange.
Since the below chassis compartment is pressurized... one might think the actual grid dissipation can perhaps be increased
via
this heatsink action ?? [GG mode]
Am I out to lunch here ???
Later..... Jim VE7RF
### Did anybody actually read the above ???
Later.... Jim VE7RF
