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Reviews For: Ten Tec Centurion

Category: Amplifiers: RF Power - HF & HF+6M

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Review Summary For : Ten Tec Centurion
Reviews: 55MSRP: 1895.00
Description:
Full QSK, a pair of 3-500Z tubes for 1300 watts PEP on SSB.
Product is not in production
More Info: http://radio.tentec.com/Amateur/Amplifiers/TT422
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00554.9
KE4EX Rating: 2003-05-09
#4# $4$ = :>) Time Owned: 3 to 6 months.
I will not get wordy. I will not slam other amp's.
I will not forget the best move I have ever made.
I would like to thank you Paul AD3G, Great advise.
I would like to say I am very happy with this amp
All the updated mods in place.
IAW http://www.hamradiomarket.com/Articles/Ten%20Tec%20Centurion.htm
Haven't had the heart to cutout the side, YET. Thanks Bob N5CNN very impressive. No wonder the TenTec Centurion is one of the most sought after amp's on the market. Imagine with a new black face plate, MOMMA.
Thanks for reading.
KD7EFQ Rating: 2003-05-08
Impressive... Time Owned: 0 to 3 months.
I just pulled the cover on my recently purchased
MINT condition used Centurion and WOW, looks
like it's built to last. At the price I got it
for, It's well worth it. Only thing loose from
shipping was the 10m expansion board which
snapped firmly back in place. It's not a 1.5 KW
100% duty cycle amp, but for me it's plenty.
1300w is close enough to legal limit for me.
Keeps me Honest!
W4SK Rating: 2003-04-26
Great Product Time Owned: more than 12 months.
With apologies to John Cameron Swayze, "it takes a licking and keeps on ticking". The best part about the famous Ten-Tec service, is when you don't need it at all. This amp has to be the best value on the market today. Quiet operation, tough (and cheaply replaced) tubes, honest published specs, and a large group of customer-friendly hams only a phone call away. In the market for an HF amp? Do yourself a favor, and get one of these.
N1TS Rating: 2003-04-12
Excellent Time Owned: 3 to 6 months.
I have the new black front panel model. Same as previous models, just a different color. Matches my IC 756 Pro nicely.

Very quiet, conservatively rated. Excellent QSK. My experience with tech support for a few technical questions was excellent.

RF Parts matched pair of 3-500ZG should last a very long time.
K5UJ Rating: 2003-02-20
Destined to become a classic Time Owned: more than 12 months.
Ten Tec hit a home run on this one. Since its release the Centurion (a class AB2 amplifier) has become a welcome addition in a long line of 3-500
linear amplifiers going back to the SB-220. Over the past 4 to 5 years, its price has moved up about $400. However, compared to Brand Z (not QRO), it nevertheless is a good buy given its standard features such as QSK, inrush protection and full metering, which are expensive options or unavailable on Brand Z. A good buy becomes a great bargain if you purchase one used under
warranty from the Ten Tec factory.

The Centurion is my first amp so I can't compare it to others as an operator, but rather as a reader of reviews, spec. sheets, and someone who
has looked under the covers of a few of the competing amps. I've owned mine for about 18 months. It arrived in two boxes, one with the built chassis and cabinet and the other containing the pair of 3-500ZGs from RF Parts. These have been good tubes, very reliable at a reasonable price--around $270/matched pair. Once everything is unpacked, the first thing you have to do is remove the cover, plug in the tubes and attach their anode heat sinks and the leads to the plate choke board with an allen wrench
supplied by Ten Tec. The first time I tried to do this, one of the cover screws stripped and wouldn't come out. When you have a new 2 kilobuck
purchase on the table your brain shuts down. Ten Tec advised me to back it out with a couple of screwdrivers (why didn't I think of that) and they had a new set of screws in the mail to me that same day. Out of the box, a set
screw on the bandswitch shaft has to be moved so the band switch can be turned to the 10 meter position, and a 10 meter module has to be plugged
into the input low-pass filter board. The module is available from Ten Tec at no extra cost upon furnishing them with a copy of your license, which you can fax to them when you order the amp. Otherwise the Centurion comes with
a stock board for 160 - 15 meters. The module is in the standard Ten Tec plug-in design.

Naturally, with the cover off, I took the opportunity to eyeball the hardware inside. Everything looked very good to me. I didn't see any cheesy shortcuts or attempts to save a buck by using flimsy components, cheap pc boards, or thin sheet metal. One example: the socket cage was a rugged looking platform stamped out of thick aluminum and mounted with machine nuts and bolts that fit flush inside the metal. No sockets attached to strips of thin sheet metal being held by porcelain standoffs like what
you would expect to see on an amp built in some guy's garage, and no signs of hasty assembly such as solder splatters, which I've seen ahem, elsewhere. The transformer is a Hypersil rated at 2.5 KVA CCS, weighing 35 lbs. It most certainly does the job. Overall it had the look of a professional piece of equipment in a relatively compact table-top cabinet, weighing in at 52 lbs. A single permanently lubricated fan is positioned to draw air in over the power supply and exhaust it out through the rf deck including the socket cage.

The manufacturer strongly recommends that the Centurion be powered with 240 v. service on a 20 a. circuit. The first thing I noticed on power-on was how quiet the fan was. Ten Tec must expect that the Centurion will be purchased by a lot of first time amp owners because they included one or two small "tutorials" (my term) in the manual on such things as the need to make
sure your feedline and antenna hardware can handle the juice the amp produces. No more 58U and antennas with the word Junior in their names!
The instructions were clear with plenty of warnings about avoiding excessive grid current, and the circuit descriptions, schematics and board pictorials were complete. I ran mine with the Ten Tec Omni VI and Corsair II, which are both equipped for qsk operation and are compatable with the Centurion. I can't comment on how it would run with a non-Ten Tec radio.

Tuning the amplifier is pretty easy--you basically tune for max. output, checking the grid current to make sure it stays below 260 ma and is further minimized as much as possible while at or near peak power. Ten Tec recommends tuning by driving the amp with cw dits and this makes the job a lot faster and more accurate. The LED power bar comes in handy for this. Speaking of the power bar, you'll quickly get used to having that strip of LEDs flash across part of the front panel in synch with the Centurion's output power levels since they are a much faster form of feedback than most analog meters. The rest of the metering is a dedicated plate current meter
and a multimeter for Ep, Ig, and forward and reflected power.

Since it had been about 20 years since I operated anything with power tubes, I was a little nervous about tuning the amp the first time and there were a few things I did such as running a carrier into it a bit too long, while figuring out how to resonate the tank circuit. None of this bothered the amp at all--it does indeed seem to be forgiving of first time operator mistakes and it wasn't long before things became a routine of first tuning the amp into a dummy load, tuning the antenna feedline transmatch with a swr
analyzer, switching out the analyzer and putting the amp on the line to the transmatch and touching up the load quickly on the antenna and logging the settings for each band. Input SWRs to the amp were nominally low. While running with the Omni VI, once the Centurion is tuned up, it's operation is pretty transparent--almost like having a third rf stage in the Omni because
the amp sequencing is so good.

One problem developed about 4 months ago with a high res. short in the p.s. primary. By this time, the amp was out of warranty, however after returning it for service and upon picking it up (my option since I just happened to be
passing through Tennessee at the time), the company only billed me for labor, thereby saving me the cost of a new transformer. The rest of the
time, its operation has been great. The extra watts have been real nice to have on a noisy morning or night on 75 and 40 during poor conditions, and the power together with the qsk have a made those dx cw pileups easy to crack.

One thing I learned when shopping for an amplifier is that the power out spec. doesn't tell the whole story. The rest of it is the tx time limit at x duty cycle and related to that, the amount of "headroom" you have there.
A balyhooed claim of 1500 watts out doesn't mean much if the amp is tuned up so tight it squeaks and its time limit at that level is limited at 100% with an expensive tube lineup. In the case of the Centurion, Ten Tec claims a 10 minute time limit at 1.2 kw, and a 50% d.c. For keydown modes the power limit is 650 watts. Forget about hype. This means you can ragchew if you
want to at a cool 6 or 7 hundred watts, and go to 1200 in a pileup (the manual calls this "new country mode"). If this is enough for you and your rig can produce 100 watts, then this is your amp. If you want 1.5 kw, 100% duty cycle forever then there is a fine company making a great product for $3500 and you should buy one--it's that simple, but remember, you may need a
backup amp someday so...
Recently Ten Tec went to a black front panel and top cover for the Centurion and it looks f a n t a s t i c.
K9UNA Rating: 2003-02-20
Really nice Time Owned: 0 to 3 months.
After much obsessing between a QRO HF 2000, a Ameritron AL-80B and the Centurion, the Centurion won out. I think all three are fine moderately priced amps. This is why I love (and bought) the Centurion:

1) It has been manufactured for over 10 years and the bugs have been worked out.
2) It has a nice size the easily fits in my shack.
3) It is certainly heavy, but light enough for me to more around.
4) It is UPS shippable (if I ever needed to send it back for repairs).
5) TenTec has a great reputation for servicing what they make.
6) It doesn’t use exotic parts; even the meter lights are easy to come by.
7) The interior layout is beautiful, very neat and clean.
8) It uses common 3-500z tubes (as does the QRO and 80B). These tubes are legend. They are easy to get and they will be around for a long time. You can get a matched pair for under $250 if you are compulsive like me ;-) With that said, it seems like the tubes will last forever if treated well.
9) It tunes very easily.
10) It is VERY quiet!
11) The 10 m mod is FREE.
12) QSK built in.
13) Sounds good on the air.
14) People that have them love them.
15) Instant warm up.
16) Puts out a respectable 1300w+ on SSB with 100w from the exciter. 1300w=1500w as far as your signal is concerned.


When I got my amp I put in the 10 m mod (a simple plug in circuit board). After setting up in my station I found that I didn’t have any output at all. I opened the cabinet and checked all of the connectors. I pushed on the 10 m board to make sure it was seated right (it seemed to be). Still no output! Arrgh, I called Ten Tec and talked to Paul, he was very nice and professional. He suggested that I try putting in the old 15 m board to see if that would work. I did and noticed that it seated lower then the 10 m board did. I re-seated the 10 m board and guess what, it seated lower too. I guess it was stuck on something. Anyways, the amp then worked perfectly. The reason that I’m telling this story is to illustrate how good technical support can save the day. With a lesser company I would have had to send the amp back (as you can tell I’m not a EE). Never underestimate the importance of customer service.
N6VUJ Rating: 2003-01-23
A nice budget amp. Time Owned: 0 to 3 months.
Cons:

Light Duty Band Switch (but then again Ten-Tec only rates this as a 1 kw amp).

Ten-Tec had switched to a different band switch knob then the one pictured, (the new one was a little too smooth and low profile creating a potential for your fingers to slip and mar the front panel).

The chassis is Not alodine coated.

You will find that many of the other manufactures including Command, Alpha, Ameritron, QRO, etc do alodine coat there chassis.

Dials only labeled 1-10 (makes it harder to replicate tuning by the numbers).

Transformer is not epoxy coated, additionally, due to this mine exhibited a buzz in the windings on key down.

The meter lenses are a bit dark for easy meter reading in a well lit room (I think they have made the lenses darker then in the earlier models).

The power cord strain relief (right angle type) was installed as to point the power cord straight down into the desk top making for a potential wear spot, a better method would have been to use a straight through style strain relief.

-

Pro's:

Nice tubes

Nice rubber coated knobs.

Easy tune up.

Low noise.

-

I had sent mine back to Ten-Tec since it had a defect right out of the box that could not be resolved in a reasonable amount of time. (would have been at least 4-6 weeks, and beyond the 30 day evaluation period).

All in all I think it is a nice budget amp but certainly not in the same class as a Henry, Commander, or Alpha.
K4MO Rating: 2003-01-21
Top Notch Amp Time Owned: 0 to 3 months.
Very quiet, smooth tuning, looks nice, built well ... as 2 x 3-500 amps go it is hard to beat. Now I just need to replace the old Eimac tubes with some Chinese copies that the anodes won't fall over against the grid in! When that happened the amp didn't self destruct ... it just quietly blew one fuse and went dark. No sparks, smoked diodes, or grunting sounds ... well protected and properly designed.
N0LOM Rating: 2003-01-15
Excellent Performer Time Owned: 0 to 3 months.
I recently bought the Centurion and it is fantastic in every respect- The QSK switching- the quietness of the amp- and the ease of tuning up on the various bands. Nice knobs for plate and tune. The built-in wattmeter measures accurate to within 5% of actual output.

The ruggedness of the 3-500ZG's is now a legend, and they are not expensive to replace if you ever need to- about $270 for a matched new pair. The inside of the amp is built with quality components throughout, and it is cooled completely by a fan that does not distract you like some amps do.

Rugged - easy - reliable - Made in the U.S.A. -the way an amplifier should be built.
W0CKI Rating: 2002-11-25
Boy, do I agree Time Owned: more than 12 months.
Had it for 2 plus years, been great. Works better than most and is very forgiving. It's a bargain at the price. Been a Ham since 54, best I've owned.
73'S Gary Bernard, W0CKI