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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
AB3CX Rating: 2006-12-23
Issue Time Owned: more than 12 months.
Although this amp is a fine performer, Hams should be aware of a quality issue that exists with the power transformers for the Centurion 422B made 2004-2006. The long term in house transformer winder left thecompany sometime within the past 3 years, after which transformer making was outsourced. A number of Centurions from the past few years then had transformers go bad with shorts. Ten Tec just began replacing these with new units last week. Mine was a 2004 Centurion in which the power transformer shorted for no apparent reason. Because I am a second owner, so the cost to me was over $500 in repairs. Paul Clinton at Ten Tec was not very helpful, and blamed this problem on anything and everything(arc, power line surge, lightening) except the ongoing quality issue. Other people in the service department were more honest with me about the issues, and gave me the full explanation. Although I was initially told the company would not charge me full replacement cost, eventually they did. The replacement took 3 months to get, during which time I was amp-less. I suggest that if you are considering buying a recent 422B, that you find out from Ten Tec if the power transformer is from one of the questionable lots according to the serial number. I'm done with Ten tec after this experience.
N1SU Rating: 2006-10-20
Still the best Time Owned: more than 12 months.
I liked my first Centurion so much I bought another one.

1300W+ on SSB. Easily produces 1200W on CW as shown by my LP-100 N8LP wattmeter. Cooling design is excellent - plenty of air flow to keep the anode seal, pins and envelope cool. The anode choke is right in front of the fan.

Paired with a TenTec transceiver QSK CW operation is outstanding at any speed.

The PEP wattmeter is nice to have for SSB operation.

Never had ANY trouble with mine. Always ready to go, no complaints.
NO9E Rating: 2006-10-06
Good buy! Time Owned: 6 to 12 months.
Mine is an early model.The fan was loud to me, after owing a SS amplifier with no fan. The replacement fan was not quieter, and IC on the QSK board became damaged in the process. Parts from the TenTec service dept came free and I repaired the board myself. I also added a thermostatically controlled fan according to an article by Bill Hutchinson. This makes the fan quieter although not inaudible. The fan comes to full speed at 150 F exhaust. Perhaps part of the problem with the noise is that the amp is on the left side, venting directly into my ears.

I like the quiet switching and smooth QSK. Tuning by the numbers is very fast, especially with the "low power" key of Mark V Field. Metering is not especially accurate. Meters show much less power on 10m than on other bands but an external measurement with a dummy load shows an identical amplification on 10 and 20m: about 13 times in CW.

I enjoy using the amplifier. Compared to my previous 500W solid-state amplifier, it needs tuning, but this makes perfect SWR unnecessary. Also, despite only about 4 db more gain, I feel that I am noticeably more successful in pileups.
W0RER Rating: 2006-09-28
Most Excellent Indeed Time Owned: 6 to 12 months.
I, too, like KY6R, have the Centurion matched up with an Orion II and both products have worked perfectly together. It is a rock and roll station to be sure!

Simply put, I agree with the previous reviewer: Most Excellent indeed!

David, W0RER
KY6R Rating: 2006-09-28
Most Excellent Time Owned: 0 to 3 months.
I had a Titan III before - which was very nice, but moved and have a much smaller shack. This amp is also fantastic - like the Titan III, is very well built and has the perfect "footprint" for my smaller shack. Paired with the Orion II, and I am in nirvana.
KE6PID Rating: 2005-07-29
Good Value-Trouble Free Time Owned: more than 12 months.
I can honestly say this amp is great. I have had no problems with it at all. It's a classic grounded grid design with 2 3-500 tubes. It will easily produce rated power on the lower bands, however up on 10 meters it's down a bit. Maximum is about 800 watts on 10, but since I don't run the amp at full output often this has not been an issue. BTW, the amp as delivered will not work on 10 meters, but Ten-Tec will provide an input board and instructions on how to modify it with the appropriate credentials from the buyer.

I especially like the way the amp is finished, nice large meters, a peak reading LED bar graph power output indicator and smooth feeling geared drive and tuning controls with log scales. Inside it's well built with conservatively rated components. Layout allows for pretty easy servicing. Classy.

I have found the harmonic content of this amp to be surprisingly low, I measured the spurs and all were down at least 60 Db from the main carrier. It should play nicely in a suburban environment. I have also noted it�s pretty broad in the tuning department, you can QSY within the band without needing to retune most of the time.
AD3G Rating: 2004-12-30
Wonderful amp Time Owned: more than 12 months.
Probably the best pair of 3-500 's amp made today. Tunes easy,super quiet,famous TT service if needed. It's a shame TT didn't design it with a higher plate voltage for a little more output,but conservative design probably means a much longer component lifespan.
They're a little pricey when new,but a bargain on the used market when you compare them to new price,grab one if you can find one,you won't regret it. Mine is 10+ yrs old and never had any failures of any kind,and it has A LOT of hrs. on it. Very dependable.
K9LEO Rating: 2004-07-30
Great Amp Time Owned: more than 12 months.
I have had the Amp for 5 years now and will never get rid of the amp while i am a Hamm. Also good customer service as well.
KA1BQJ Rating: 2003-11-28
Exellent Amp Time Owned: 0 to 3 months.
Hello.

I recently sold a Kenwood TL-922a that I had purchased from AES in 2002. The amp was in absolute mint shape and worked perfectly. However, I was getting concerned about available parts for the amp, should it need service at some point in the future.

I began looking around at several amps - from Ameritron, QRO, Command, ACOM, Tokyo Hi-Power and others. Just about everything available was considered.

Some of the key factors affecting my decision were (not in any order) QSK, quality of construction, reputation of the manufacturer, service, etc. Price was also a factor, but not the overriding one. I was disapointed with Ameritron as the newer style amps - such as the 800H were a bit cheezey (IMO) in materials used for construction. QRO seemed a bit crude to me.

I decided on the Ten-Tec Centurion and ordered the new 422B (black version) from Ten-Tec. This is a quality, well made piece of gear. I was a bit surprised at how large the amp is...really much bigger than I had thought.

The amp arrived in a well packed box with fitted foam protecting the amp. Installation of the tubes was easy. Powered the amp up and got 1200+ watts out according to TenTec's specifications. Fit and finish of the amp are excellent and I really like the new black color.

As I used the amp more, I became a bit concerned about the metering, though. I didn't seem to get the sampe Grid and Plate values as was indicated on the final inspection sheet from TenTec. I phoned TenTec on Wednesday and explained my concern to the John, who had performed the final inspection. John was very helpful and indicated it was possibly a bad meter and would be sending a new one out next Monday (12/1). After some further testing I determined my tune-up procedure - using a high-speed cw burst at about 50 wpm was the cause of the confusion. I tried tuning the amp up with a solid carrier and everything is working perfect. The amp's meters don't move fast enough to accurately show the grid, plate, power output, etc., values when using highspeed CW to tune the amp.

I found the experience dealing with TenTec to be a good one. This is my first piece of TenTec gear and I've been a ham for over 25 yrs. I had rigs from Kenwood, Icom, Yaesu and others. I will be purchasing an Orion in 2004!

Regards,
Tom / KA1BQJ
N3ND Rating: 2003-09-04
Outstanding Value Time Owned: 3 to 6 months.
I purchased a new Centurion 422B after discussing the amplifier with Ten-Tec personnel at Dayton. This unit replaced a great amplifier, an Amp Supply LK-500ZC, that I sold a few years ago because of low usage. What a dumb move!

I elected to buy the Centurion for several reasons.
1) Been in manufacture for 14 years.
2) Ten-Tec service -- if necessary.
3) Good looks -- especially in the new black package.
4) Price -- over $1K less than a unit with only 200 watt greater (legal) capability.
5) LED peak wattmeter function.
6) eHam reviews

The in-stock unit was received in two cartons -- the tubes shipped packaged separately from the amplifier carcass. After installing the two 3-500ZG tubes and checking the wiring to make sure the amp was wired for 240V, I decided to put it in line. Where’s the power switch? The on-off switch is “hidden” underneath the front panel that makes the unit more secure from unauthorized or curious onlooker’s hands (read this as children!).

Initially the unit did not appear to be performing properly. The internal wattmeter showed only 600 watts output on both the internal analog meter and the LED wattmeter, the maximum plate voltage showed only 2400V (should be ~3100 V), and the plate and grid currents could never approach anything near maximum. After much checking and for whatever reasons, it was determined that all the calibration controls were not set accurately even though the provided check sheet suggested the amp went through the calibration process. With Ten-Tec’s help, I was able to perform the necessary calibration alignments. The unit, indeed, was working as designed.

Since I am primarily a CW operator, I was most interested - and concerned - with the QSK function of the unit. Ten-Tec uses a mechanical relay, not vacuum, for the RF output switching and I was worried that it would not switch fast enough for hi-speed CW even though Ten-Tec sales at Dayton said, "Not a problem." My Yaesu FT-1000D has facilities to allow a "contact" make before applied RF and I made the appropriate cable to work with the Centurion. Any concerns I had with QSK operations were quickly dispelled. I ran several tests with friends at 35 WPM switching the amplifier in and out of circuit while they listened to -- and watched -- my transmitted signal and there were NO differences in keying attributes. The QSK is slick! And the QSK is very, very quiet. Totally quiet, in fact, and below the noise of the already quiet internal amplifier cooling fan.

By far, the greatest asset in the amplifier is the LED peak wattmeter function. This is most evident during SSB operation since the analog meters do not give an accurate view of peak values. I am convinced that the lack of this asset in other amplifiers is a major cause of amplifier overdrive resulting in the ever-present wide SSB signals you’ll hear on the bands.

Dislikes? Only one. The tuning and loading control dials are not well marked for initial setting when changing bands. I’ve remedied that with color-coding on the dial skirts. This is a very minor complaint but one that I think Ten-Tec should consider changing.

I am extremely pleased with this purchase. I have not had any arcs and sparks even on the occasion when I try tune-up on the wrong antenna! Anyone looking for a reliable, good looking, and medium priced HF amplifier needs to look no further than the Centurion.