3CX6000 10Kw på 6m

Alt hvad der angår modtager, sender og perifer enheder.
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3CX6000 10Kw på 6m

Indlæg af oz7c »

På amps refelcktor har igennem lang tid kørt forslag til:
En lidt større PA trin til 6m.
Ja hvorfor ikke ? Det var måske noget for en selv bygger.

Here, the small 240 vac variac is installed..... complete with a right
angle drive, that goes through the rear panel.
Small Variac is used for filament voltage adjustment. Pretty slick, unique
<https://www.youtube.com/watch?v=1BzsQrx ... g7roROkJzY>
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73 Boye
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Tilmeldt: tirs jan 23, 2018 0:06

Re: 3CX6000 10Kw på 6m

Indlæg af oz7xf »

Keramisk luftkølet rør og en autotransformer duer ikke.
Må jeg bede om væskekøling og roterende omformere, kul og slæberinge.

Jeg har haft en næsten lignede krabat kørende, men blev træt af blæserstøjen, så nu er der skiftet til 2 stk 3-500GZ med en ganske svag køling. Og så rydder de ikke lokalet som en håndgranat, hvis jeg mister forbindelse til antennen. Den 3-fasede HV transformer knurrer bare lidt og jeg slipper Vibroplexen.

vy 73
OZ7XF, Allan
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Tilmeldt: søn feb 04, 2018 2:30

Re: 3CX6000 10Kw på 6m

Indlæg af oz7c »

Her er en ny video

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
20%....to 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


73 Boye
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Tilmeldt: søn feb 04, 2018 2:30

Re: 3CX6000 10Kw på 6m

Indlæg af oz7c »


OK, the 2 (brand new) x Ameritron ALS-606's only put out barely 300w on
6m (and only 400w on 75m). Ready to tear our hair out. Plan C was the new
ALS-1306...which actually does work.

Cut to the chase. 10 kw CXR out with aprx 600 w of drive. (brand new
Coaxial dynamics 25-60 mhz, 10 kw calibrated slug). Line section with the
10 kw slug / meter has the pep kit installed. Line section with 1 kw slug,
between ALS-1306 and input to the tube amp....(to measure drive into tube
amp). Line section with 25 watt reflected slug between ALS-1306 and input
to tube amp....(used for tweaking the PI tuned input, with it's 2 x air
variable caps).

Jennings ceramic vac tune cap....and a Swiss made (Comet) ceramic vac load
cap. All testing done on 50.125 mhz.

The big dummy load consist of 32 x 1600 ohm globars (18" long) in parallel
to make the 50 ohm commercial DL. 7-16 Din on output of tube amp and also

B+ sagged quite a bit with a CXR. But with every 1 volt AC going in, he has
aprx 25 vdc coming out. The line sagged 6 vac from the street, so we lost
150 vdc. Then another 125 vdc through the 40 ohm glitch R. No load B+ was
5900 vdc. Loaded to 3.125 amps of DC plate current, it drops to just 4300
vdc. (It would have been 4575 vdc without the above pair of V drops). Then
you have the typ 5-10% drop in the B+ supply anyway. Then the small V drop
across any 2 of the 4 x strings of diodes in the FWB.

On SSB / CW, it drops very little. This is the difference between a static
load....and a dynamic load. Total of 30 uf of filter caps (2 x 60 uf @ 4 kv
oil caps in series), so we don't have a huge amount of energy stored in the
caps. (522 joules).

Plate current = 3.125 amps
Grid current = 500 ma
Loaded B+ = 4300 vdc

DC input = 13,437 watts.
Power output = 10 kilowatts.
Anode Dissipation = 3437 watts.
Eff = 74.4 %

Bias can be toggled between 50 ma idle and 200 ma...(Class AB). (toggle
switch changes the tap on the series diode string, used for bias).

Special thanks to John Lyles, K5PRO, for his assistance on Saturday,
conducting some SRF (self resonance freq) tests on some doorknob caps, on
his Vector impedance meter. (Old HP 500 khz to 108 mhz unit). We changed
out the bypass caps at the cold end of the fil choke.

Scott designed and built the HV supply. I designed the unique RF deck.
(Scott also built the RF deck).
The 80-15m 3CX-6000A7 amp will be the next project....already in the works.
I have most of the RF deck designed.


Later.... Jim VE7RF
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73 Boye