Ten Tec Titan II
Biggie from Ten Tec
by Bob Hutchinson, N5CNN
this really 1000 X over my first Ten Tec?
It sure looks that way at first glance. What I mean is - some many years
back my first transceiver was the classic Ten Tec Argonaut 409. After
passing the General, my first sideband contact was made several hundred
miles away with 2 1/2 watts on 40 meters powered with a small Die Hard
excitement that was.
Stayed up all night talking on 40, 15 and 10 meters on my 40M dipole
antenna. It appears this Ten
Tec has a
1000 X advantage over my first one. Of course, I later bought the
companion Ten Tec 405, 100 watt linear amplifier and thought I was a power
broker with it's wonderful 50 watts
look really close inside, we will take this Ten Tec Biggie to the WIA bench
and run it through our standard operational review.
About the box -
Ten Tec has the equipment for making big foam-in-place end caps for the
amplifier for superb protection from the rigors of shipping. No
shortcomings in the shipping arena. The amplifier came properly seated in
the box upside down so it ends up right side up when the box is flipped
onto the table or bench.
Some disassembly - assembly required?
For convenience, the amplifier has only a few screws holding the top cover
on. The balance of screws are in the accompanying plastic bag containing
extra fuses and transformer screws. I removed the cover and set it aside
so we could continue with the assembly, but there is none at this point.
The Biggie tube is already installed and the transformer will wait.
Ten Tec has been in the enclosure and cabinet making business probably
since the beginning and their experience shows with this product.
Everything appears to well though out and engineered.
OK, it's tent duty
amplifier is nice and light without the plate transformer so I set it
inside the light tent onto the caster equipped roll around plant stand. I
always like this part, working the
Olympus digital and the lights. I try to share everything inside with
space, nothing cramped or cluttered. First quality components. Why, they
several tubes in this compartment.
and Tune air variable capacitors
are driven with smooth 6:1 ball vernier
drives. The band
switch is a longer
component than found
in most amplifiers. The coils are not cramped or too close. Everything has
plenty of room here. The long band switch places the wafers in good
position where they need to be so short leads can be utilized. The entire
switch is well supported
by the many soldered connections to components. If there is plenty of room
in a case this is a good way to utilize it.
Cooling - Centrifugal
squirrel cage type blower
Unusual mounting of the cooling blower for a Ham Radio amplifier. Most
makers mount the blower inside where it pulls air in, over and around
other components in the box and into the blower inlet. Then it is forced into
into the pressurized plenum and through the radial/axial heat exchanger
surrounding each tube and out of the box.
Ten Tec cools this
amplifier with a different system. Fresh cool air enters the blower from
under the amplifier and is forced into the pressurized plenum chamber and up through
the axial/radial heat exchanger of the Biggie
Svetlana 4CX1600B ceramic/metal tetrode.
There is a bail under the front that can be flipped down to raise the
front of the amplifier to a better viewing angle. The manual says the
underside cooling air entrance will get plenty of air with the bail in
The large plenum chamber houses circuit
boards, AC mains, soft start, metering,
control circuits, etc. The top amplifier cover is well ventilated over the RF
and power supply sections with plenty of holes and slots for convection
cooling. None of this heat influences the tube cooling. In tube type
linear amplifier operation, the great majority of the total heat generated
is from the tubes. Heat not generated by the tubes is not significant at
high power output levels.
circuits in the breeze
I removed one side and the bottom cover to expose the bottom of the
amplifier which is also the cooling air plenum. Reason the top side RF and
power supply sections are so uncluttered is here, where everything else
is. Except for the rectifier/filter, all the circuit boards are here, in
the breeze box. Mains start and in-rush or soft start circuitry is here
along with screen, grid, bias, QSK, SWR and ALC control circuit boards.
It appears that input impedance matching resistor networks are used for
the tetrode tube. Tuned input circuits are not necessary. The input board
is standard with input filter circuit that rolls-off input of frequencies
above 15 meters. An optional replacement input board for us so called legal, yammer,
yammer, yammer folks rolls-off frequencies above 10 meters. However, there
is no mobile mounting bracket included with the Titan II and it will not
operate on 12 VDC without a VERY HIGH capacity DC to AC inverter, also not
Well yes, it seems the centrifugal blowers required by these indirectly
heated tubes, with radial/axial heat exchangers, have to turn fast and
they often make noise at a frequency that is irritating to humans. The
amplifier maker provides the cooling necessary for the demands of the
Tec perfected reliable QSK circuits years ago and the feature is a
specialty of theirs. As far as I know all their amplifiers have or have
had fast T/R circuits capable of full break-in CW. Of course, this type of
circuitry usually results in smooth VOX operation with little noise.
Svetlana 4CX1600B tube
Ok, here are some
snippets about the tube. It could all be folklore.
4CX1600B tetrode tube is not a military tube and was produced just for
the Ham Radio amplifier market in the U.S.
It is a
2,500 watt dissipation military tube disguised as a 1,600 watt
dissipation tube so an amplifier utilizing this Biggie could be FCC type
- It is
considerably more power capable than two 4CX800A type Rusky tetrodes.
Replacements are readily available at inexpensive prices.
tetrode, similar to the
4CX800A/GU74B tube, requires
some simple impedance matching but no tuned input circuits.
- It is just loafing in
legal ++ Ham Radio amplifiers and is capable of much more power output
with a healthier plate transformer.
Ten Tec has always
provided well done manuals. This one continues with that tradition.
the power supplies?
With 240 VAC mains
the large single purpose transformer provides about 2,050 VAC to the
bridge rectifier's 20 6 A., 1,000 PIV, 6A10 type Biggie rectifier diodes.
Filtering is handled by nine high quality Mallory computer grade
electrolytic capacitors. B+ production is 3,000 to 3,150 VDC B+ with no
load. Everything is open and easy to get to if service is every needed.
Note the short length
of the Mallory caps.
for tube cathode heater, metering, screen, bias, QSK circuits, etc., is
provided by a multi voltage transformer.
One of the big
meters is dedicated to plate current and the other is switched to read
high voltage, screen grid current,
forward power or reflected power. There is also a horizontal green LED bar
type power meter with the red 1,500 watt red LED at the right end of the
bar. This is similar to the bar display on the original Titan.
The band switch has
two position for 16OM and two positions for 40M. The 40B position is for
the 30 meter band. The 15M position is used for 17M operation and and 10M
used for 12M operation.
Protective circuits -
can ya break it?
A plate current
protection circuit will shut down the amplifier if current exceeds 1.5 A.
The standby switch indicator lamp will go out, indicating shut-down. The
switch is cycled to reactivate amplifier. Screen grid current absolute
maximum is 55ma, which you should never see on the screen grid meter as
5ma to 20ma is normal current. Screen grid current and control grid
current red LEDs overdrive indicators should never come on. I never
noticed even a blink during this review and screen grid current never exceeded
Our test bench is equipped with a 2000 watt fan
cooled dummy load and a 3,500 watt low pass filter. For output power
measurement, Bird 43 and Coaxial Dynamics watt meters are utilized, cabled
in series. We normally have 2,500 watt slugs in both meters but for higher
power amplifiers we sometimes use 5,000 watt slugs. The bench has a superb
10,000 watt antenna switch utilizing Jennings vacuum relays, designed and
built by this writer, for access to 75M & 40M dipoles, 20M, 17M and 15M verticals
and the dummy load. A putt-putt wattmeter is used between
exciter and amplifier to measure drive power and SWR.
For high voltage readings
we utilize digital voltmeters and 6KV and 40KV Fluke high voltage probes.
We average readings with two setups to assure no surprises with accuracy.
Accuracy of measurement
For this project both wattmeters are equipment with 2,500 watt slugs.
We record the average of the two wattmeter readings. Both Bird and
Coaxial Dynamics spec. an available inaccuracy of + or - 5% of slug rating
at a mid-scale reading. This works out to be an error factor of + or - 125
watts at mid-scale with 2,500 watt slugs. Utilizing two instruments gives
an assurance of accuracy if both give the same or similar readings. The maker's don't
mention accuracy at close to full meter right deflection, but we assume
Will this fine box
perform? Does it run?
I went through my
systematic load test for the following bands on the dummy load. Drive signal is CW.
Data below is grouped:
Screen grid Current
MA / Plate Current MA / CW Power Out Watts
QRP Settings Column
Medium Drive Column
Max. Drive Column
Ten meters not enabled on
this amplifier yet.
Over drive column on the
The indicated B+ is 2,900 VDC with no load and 2,700 VDC under load at
legal limit. The measured B+ is 3,000 no load and 2,600 under load.
During the testing we did not
received a single overdrive indication from the red LCD screen grid or
grid overdrive lamps. The plate current protection circuit trips and shuts
down the amplifier when 1.5 amps is exceeded. It tripped once and was
reset by cycling the standby switch. Tuning was straight forward, easy to
manage and repeatable. The Titan II controls on the right side of the box
are easy and comfortable when the amp is residing on the left side of the
station. The fast T/R circuit in this
nice QSK capable amplifier could not be heard during testing.
The Titan II is produced
with the highest quality components and the case and layout are superb.
Cooling is more than adequate for the most demanding
Amateur service. It will deliver legal limit plus power to satisfy all Ham
Radio needs. Ten Tec has designed the robust Titan II around a tube with
much greater capacity than needed. The
Svetlana tube is
operated conservatively and should outlast any average Ham owner.
As you see from the
pictures, the Titan is a fine looking amplifier. I like the gray color and
the superb cabinet quality and style. If we had more room and I had more
time, I would keep this one, but on to the next review. Wow! I love this
Ham Radio stuff. The titan II has been replaced by the titan III. Check the
If you have any
questions about the Titan II or any other amplifier we have reviewed,
please call or email me.
Bob Hutchinson, N5CNN
President and Founder
Wireless Industry Association
If you would like to
publish an article here contact Bob