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Message |
    
Keiths121
Junior Member
Username: Keiths121
Post Number: 11
Registered: 8-2009
| | Posted on Monday, August 31, 2009 - 10:07 pm: | 
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Looking for a new amp. Looking at either getting the TS 667v or TNT T800. I guess the main question is what makes the TNT T800 different from the TS 667v in the sense that they both have 1 2290 driving 4 2879's, but xforce states that the TNT will do 1000 PEP. Is this true or fluff? Both of these amps are nearly the same price. Also the TNT T800 draws 100 amps where as the TS 667V i believe draws 65 or so. The TNT puts out more watts so it will use more amps, but why or how is the TNT able to put out more watts? It is a tough decision between these 2 amps. I'm hoping someone could shed some light on the differences between these 2 amps and make my decision a little easier. Thanks.
KF5CTE
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Stepchild
Intermediate Member
Username: Stepchild
Post Number: 210
Registered: 11-2002
| | Posted on Tuesday, September 01, 2009 - 10:06 am: |
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Keiths121, I'm no expert but the TNT line of amps are "B" biased and the 667 is "AB1" biased and will produce a cleaner signal for SSB. I was told that if you do a lot SSB but like the power of a class "C" amp while on AM, the TNT will be a happy medium. Also I beleive the TNT is built to competition spec's and are tough as nails. As far as power, You very well could see 1kw with it if all things are perfect but 700-800w "PEP" is more realistic. Hope this helps.
Stepchild
CEF-187
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 4636
Registered: 7-2004
| | Posted on Tuesday, September 01, 2009 - 10:32 pm: |
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stepchild's got it right. if you are mostly SSB, go with the texas star. otherwise the tnt will get by, and probably give you a bit more AM power. the tnt line is their updated version of their magnaforce line. still basically an AM amp. at 13.8 volts, you'll see 700-800 on AM, a bit less on SSB, at 15 volts, nearer 1kw. the 667v will get you 500-600 on AM, closer to 500 on SSB. i've heard quite a few TS 350, 500 & 667's on 10m this year, & most sound good if the radio sounds good. a local used a 2x4 magnaforce on 10m with a stock hr2510 & it had some nasty crunch on SSB (10m). he has a TS now that sounds real good. |
Keiths121
Junior Member
Username: Keiths121
Post Number: 12
Registered: 8-2009
| | Posted on Wednesday, September 02, 2009 - 1:08 am: |
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Thanks for the info, probably going with the texas star since I mostly talk SSB. Another question will the TS run @ 15 volts or is it not recomended?
KF5CTE
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 4638
Registered: 7-2004
| | Posted on Wednesday, September 02, 2009 - 6:52 pm: |
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i've run a dx500 at 18v, don't know how long it would have lasted though. also had the voltage regulator on a custom alternator burn up & apply 24 volts to a dx1600. it too survived 5 seconds of keydown. that said, if you're using SSB, an extra volt might get you a few extra watts, 2 volts from 13v up to 15v....100 watts on a real good day. 13.8-14.2 volts up to 15? not worth the aggravation. |
Keiths121
Junior Member
Username: Keiths121
Post Number: 13
Registered: 8-2009
| | Posted on Thursday, September 03, 2009 - 10:16 am: |
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The reason I'm asking is not to get extra watts, but I have a 52 amp power supply that I will dedicate to the unit, and in theory won't a slightly higher voltage use slightly less amps?
KF5CTE
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 4640
Registered: 7-2004
| | Posted on Friday, September 04, 2009 - 12:37 am: |
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in AC circles, 20 amps draw on 110 volts can be changed to a 10 amp draw by going to 220. still the same result, just different treatment of transformers in the PS.
even though the PS will adjust to 15 volts, and is supposedlt regulated, apply a load & watch the PS back down to 14 volts. anyway, the increase in OUTPUT from the amplifier will just draw more current, so the benefit you are attempting to obtain will only result in more watts. unless of course you back down the input from the radio to produce a consistant output, regardless of voltage to the amplifier............ |
Keiths121
Junior Member
Username: Keiths121
Post Number: 14
Registered: 8-2009
| | Posted on Friday, September 04, 2009 - 3:26 pm: |
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Noticed that when I get around 40+ amps on the PS it drops to 13 volts when its set to 13.8 I am wanting only 500 or so watts out of the amp. Will my power supply be able to handle that at 13.8 volts? A quick calculation shows that 500 watts will only use about 36 amps, but we both know it will use more for the same 500 watts. is 52 amps enough for 500 watts? Will be 500 watts max, most of the time will use 250-300.
KF5CTE
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Tech833
Moderator
Username: Tech833
Post Number: 1729
Registered: 8-2002
| | Posted on Friday, September 04, 2009 - 3:47 pm: |
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Volts x Amps = Watts. Goes back to Ohm's law= E.I.R.
So, if your power supply is putting out 13.8 volts at 52 amps, that equals 717.6 watts. If your amplifier is at least 43% efficient, that would equal 715 watts of input power required.
Measure the efficiency of your amp by running it at your desired power level and measuring the current drain from the power supply. Multiply that by the measured power supply voltage, and then figure the difference between watts out and watts in to get your efficiency factor. Once you know the efficiency factor of your amp, then figuring out your power supply requirements is easy.
If you are not willing to do that, then just go way oversize on the power supply and forget about the math.
Remember, it is always best to run a power supply at less that its maximum rated output current. A good rule of thumb is to not exceed 2/3 , or 66% of the power supply capability.If you need 50 amps, use a 75 amp power supply. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 4642
Registered: 7-2004
| | Posted on Saturday, September 05, 2009 - 9:43 pm: |
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buy another 52 amp PS. check to make sure output voltages are the same & parallel them. stick with the texas star. you'll get full output in the 500+ watt range give or take with plenty of breathing room that paul suggests! |
