Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

donate to eham
   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Ten-Tec Centurion question  (Read 2699 times)
YV5MBX
Member

Posts: 71




Ignore
« on: July 01, 2004, 03:56:00 PM »

Hi,
I would like to know if the output power at my almost new (3 months old) Ten-Tec Centurion Amplifier could be increased through some modification.

73´s de Javier
Logged
WB2WIK
Member

Posts: 21837




Ignore
« Reply #1 on: July 01, 2004, 04:50:00 PM »

No.

You'd have to increase the plate voltage, at least.  The Centurion only runs about 2.6kV on the 3-500Z plates under load, and that's not quite enough to generate legal limit output power without exceeding other limits.

Besides, the Centurion only runs 0.62 dB less than legal-limit power as it is...who could possibly notice the difference if you increased the power to 1500W?

WB2WIK/6
Logged
K5UJ
Member

Posts: 80




Ignore
« Reply #2 on: July 13, 2004, 06:40:23 PM »

See this:

http://www.hamradiomarket.com/Articles/Ten%20Tec%20Centurion.htm

I have not undertaken this mod, and I do not endorse it because I think it is kind of risky, but since you asked, here it is.  You decide.

Why more power?  The stock Centurion in my experience does 1.2 kw SSB only under optimum condx, i.e. tuned up right, to a nice near pure R 50 ohm load.  And even then only on one or two bands.  Part of the problem is the input matching from 50 ohm coax to the cathodes shows at a minimum, 1.5:1 swr across all bands, in some cases gg as high as 2:1.  The input matching network is fixed; no slug tuning etc. for your shack's particular situation.  With Ten Tec exciters, that isn't a big deal--they don't fold back much unless the swr is pretty high; other exciters start folding back at around 1.5:1 making it harder to drive the amp.  Some Centurion owners get around this with a low power outboard tuner in the input, but A. that's one more thing to fool with when QSYing, and B. It shouldn't be necessary--TT just needs to make the input match adjustable.  
The result is a stock amp that maxes out at anywhere from 900 to 1100 w. in my experience, and, okay sure...that's a lot but if you bought one, you paid for an amp that supposedly does 1.2 kw and you expect that on all bands.  I did at least.  What a few hundred volts higher on the plates would do is give you some headroom I think, not to run 1.5 Kw all the time which would be a bad idea (the amp's cooling is quiet and low key and may not be enough for higher power) but to run 1.2 kw consistently with typical exciter drive.

That's the justification, but again, I don't recommend the mod.  I recommend, if you want more power, finding another amp.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!