--- In ham_amplifiers@..., 1800 Toll Free
<TollFree1800@...> wrote:
Of course, since the waveform is nothing more than a squarewave
when it hits the pair of 4CX15000's, they can take being driven by
15,000 watts.
The duty cycle is a lot less than 100 percent, overall.
### I take it they run the 4 x 15's in GG.. with screen and grids
all bonded to chassis ? If they need 15 kw to drive em....
heck.. why not just grid drive em ???
### BTW... I had a call from Arnold Howell not too long ago....
IF any of ur 11m buddy's require YC-243's... [ Eimac
SOCKETLESS version of a 3CX-6000A7 / YU-148] lemme now asap....
if he gets enough interest.... he's gonna get Eimac to do a small
production run.... BUT he won't do it unless at least 10 x tubes
are ordered.
### The YC-243 is slick.... comes with a built in 4.25" diam grid
flange vs the 4" diam grid ring on the socketed version. The
fil assy is solid silver plated bar stock.... with two huge
threaded bolts pointed straight down, embedded in the bar stock.
### Just whack a hole in chassis... and bolt grid flange [ 1/8"
thick] to chassis with 12 x 1/4-20 bolts. All silver plated..
a real thing of beauty.
### Economy Electronics doesn't sell em anymore either... and
it's Howell's design.
### They sell for LESS than a standard socketed 3CX-6000A7... and
now that the sockets from RF parts are up to $375.00.... u save
the cost of the socket as well.
### If anybody wants the Official Eimac PDF file on this YC-243..
lemme know. I'll send it to you. Next week, I'll see if I can
post the PDF file on the "files" link .. just above .."photo's"
### I came up with a way better chimney scheme than either the
Economy Electronics grey chimeny.. or Hoewll's Teflon chimney
[which is 1/4" thick solid Teflon.. and weighs a ton].
### We built a 9.5" square box around the base of the tube... and
used the original chimney in a recessed groove on top of box.
Using a Dayton 5C508 blower.. we could get an easy 320 cfm out
the top of the tube. [at .9" h2o pressure] With a 20 deg C [68
deg F] inlet air temp.... the anode diss is 9700 W CCS !
### The whole secret was the 9.5" square box. That allows plenty
of holes in chassis. The ceramic stem on the both a 3x3 and a
3x6 is small in diam.. compared to say a YC-156, etc... and there
is plenty of intake surface fin area on the underside of a 3x6.
### The latest version uses a taller box... and a solid Teflon
top.. with a 6.125" hole in it......... eliminating the aftermarket
chimney's alltogether.
### The stock aftermarket straight up/down chimney's restricted
the airflow like crazy.... due to the smaller holes u could cut in
the chassis cuz of the smaller ID of the chimney's. They were
also too big an ID... letting even more air escape on the outside
of the tube.
### You can see all 50+ pix of this on the photo page . Click
on "photo's".... then "VE7RF" [it's the photo album with the
25 kw CD slug. ]
Later.... Jim VE7RF
