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[Amps] 10 KW CCS ON 6M...USING THE 3CX-6000A7... PART 29

Subject: [Amps] 10 KW CCS ON 6M...USING THE 3CX-6000A7... PART 29
From: "jim.thom" <>
Date: Fri, 16 Jun 2023 03:49:40 -0700
List-post: <>
Here, all the final wiring has been completed, including the B+ between HV
supply and RF deck.

Top lid of the HV supply, where the blower outlet is located, was modified,
with 4 x pieces of 1" x 1" x 16" thick angle aluminum.
New angle pieces located between the blower flange, and  underside of the
top lid of the HV supply.   These 4 x angle pieces will engage the
mating air inlet on the bottom lid of the RF deck.   3/8" gasket material
sandwiched between  the 2 x flat surfaces.  This ensures an airtight fit.
The angle pieces protruding up, and into the RF deck bottom lid.... 'locks'
the 2 x cabinets together, so the RF deck on top can't move about, when
it's sitting on the HV supply below it.   HV supply is on casters...and  is
easily rolled about.

Testing on the HV supply begins next week, time permitting. Then testing
the various misc supplies inside the RF deck, vac relays, fil variac,
blower, blower interlock etc, etc..... then the entire combo together, as
one ensemble.

Tube airflow requirements are  204 cfm @ .4" pressure (with a 104 deg F
inlet air temp) for the rated 6 kw CCS anode dissipation. The EBM Papst
blower used on this 6m amplifier is rated for 320 cfm @ .9" pressure.  With
the 50% increase in airflow, the anode dissipation is increased by 7200  watts  CCS.   With a more sane 77 deg F inlet air temp, the
anode dissipation is further increased to 7900 watts CCS.  When the cfm is
increased by 50% (1.5), the pressure must be increased by the square of the
cfm increase.  (1.5 x 1.5 = 2.25).  2.25 x .4" = .9"

All that airflow is 1st drawn in through the pair of fingerguards on the HV
supply, and past the various HV components,  plate xfmr, fil xfmrs, etc,
before it gets sucked into the blower intake. That ensures  both the HV
supply and RF deck remain cool at all times.   IF the blower ever failed,
the pressure interlock switch would release, and ALL voltages are removed
asap.  In normal operation, the air pressure in the  plenum has to be
normal, before any voltages can be applied.  IE: both the RF deck + mating
HV supply  will only function IF the blower is running.

The next project is currently in the design phase.  Consists of a
3CX-6000A7 operating on  80-40-30-20-17-15m. (6 bands).  A variation of
that is 160-80-40-20-17-15m. (6 bands). This will be  bandswitched
(progressively shorting triple wafer model 88/85 switch / model 90 switch)
and a bandswitched, manually tuned, PI tuned input.  Higher B+ voltage
used.  Obviously far more complicated than the 6m amp.  10 kw CCS output on
data modes / 12 kw pep output on  SSB  +  CW.    Stay tuned for further
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