Amp spec questions.

[pistolero]

OK help me out here. Looking on Xforce's site at their TNT line.
Just as an example this is copied and pasted from their specs on the 600hd;

"Max input carrier of 10w or 300w max carrier from amp.
Max peak input 240w"

How would the amp "know" (and why would it care) if the power was coming from a radio with a dual transistor output or another amp?
And how can it make sense that it will take a 300 watt carrier when it has a Max peak input of 240 watts???

 

[AudioShockwav]

Max input carrier of
10w or 300w max carrier from amp..

Do not put more than 10 watts carrier into the amp from the radio driving the amp.
Do not exceed a carrier FROM the 600HD of 300 watts.
It will NOT take a 300 watt carrier from any driver be it a radio or another amp.

Max peak input of 240 watts

Peak Power as read on a Bird 43 with a Peak reading kit.
Again, It will NOT take a 300 watt carrier from any driver be it a radio or another amp.
There is a big difference between the dead key or carrier power, and the brief peak instantaneous power the amp can take......they are saying that the amp will take brief power "peaks" of up to 240 watts .... I for one would never drive that much power into 4 2879`s regardless of how much they swamp the input of the amp.
Carrier, or Dead key is a constant, unmodulated wave form.
There is a big difference in AVG power ( often called RMS power in error ) and Peak power ( and PeP or Peak envelope power) and mixing up the terms can be confusing.

73
Jeff

 

[9C1Driver]

And just because they are giving you MAX input numbers that does not mean it's a great idea to run any amplifier at that level.

As an example a local here ran an Omega Force S45-HP radio into a TnT 600. On AM that radio would hit 70 watts from a 5-6 watt carrier, and 70 watts PEP on SSB. That was enough to drive that TnT600 to just over 700 watts. On AM that 5-6 watt carrier input gave him 180 watts dead key OUT from the amp.

With that amp I would never expect to get 1000 honest watts from four 2879 finals. 600-800 peak watts out would be working it plenty hard. I would shoot for 500-600 and be happy at that level, whatever input wattage levels that might be.

 

[TonyV225]

I can only imagine what the signal would look like or sound like if you were to run it at the obve specs.........*Don`t do it*:blink:

 

[Turbo T]

Do not put more than 10 watts carrier into the amp from the radio driving the amp.

In that case, am I overdriving mine?

I run a Magnum 257HP into my 600HD. I'm almost certain my radio's carrier is 15 watts when fully turned up.

Of course I don't have too much trouble getting out. In fact I often cause pile ups.

 

[Mudfoot]

Enjoy it while it lasts.

 

[vkrules]

Man those specs are hard to understand am I reading that right. are they recommending 10w carrier max into a 250 as a driver and then into the 600hd for 400 rms out.

 

[AudioShockwav]

In that case, am I overdriving mine?

I run a Magnum 257HP into my 600HD. I'm almost certain my radio's carrier is 15 watts when fully turned up.

Yes.



73
Jeff

 

[n0zna]

i smell smoke and its not the toaster,hehe...

 

[vkrules]

TNT 600hd

Transistors 4 x 2SC2879
Dimensions H 4 3/4' x L 11' x W 6 3/4'
Amp Draw (maximum) 100
Class B biasing
SSB Delay yes
Pre-amp yes
Driver Required TNT 250 (optional)
Power Output (RMS) 300 Watts
Power Output (PEP) 625 Watts
Driven Power (RMS) 400 Watts
Driven Power (PEP) 1000 Watts
install recommended with 4ga wire
and 125a fuse. Max input carrier of
10w or 300w max carrier from amp.
Max peak input 240w.

 

[Captain Kilowatt]

I can only imagine what the signal would look like or sound like if you were to run it at the obve specs.........*Don`t do it*:blink:

Yup. I have always said there are amp manufacturers specs and then there are transistor manufacturers specs. Extremely rarely do the two ever say the same thing. I tend to believe the transistor manufacturers ratings after all THEY designed and made the things. The amp manufacturer simply wants to make his product look good and wants to make a sale.

 

[n0zna]

i like glass,and always will...real amps glow in the dark...

 

[space cowboy]

I could be wrong, but I'm thinking typo...

"Max input carrier of 10w For 300w max carrier from amp.
Max peak input 240w"

 

[9C1Driver]

In that case, am I overdriving mine?

I run a Magnum 257HP into my 600HD. I'm almost certain my radio's carrier is 15 watts when fully turned up.

Of course I don't have too much trouble getting out. In fact I often cause pile ups.

I guess it's all how your radio was set up. My 257HP will hit 50-60 watts on AM from a 3-4 watt carrier and I think wide open it keys 9 or 10 watts. In your case just back the RF power dial down until you hit say an 8 watt carrier....done.

 

[AudioShockwav]

but I'm thinking typo...

I do not think it is a typo, about 300 watts constant carrier from 4 2879`s is about all I would ever run too and even that is high end.
Note the AVG ratings ( well they say RMS...no such thing, but) They are saying even with a driver ( 4 2879`s do not need a driver) that it will do 400 watts, throw the peak power out the window for a moment.
With no driver ( more like it) 300 watts.
2879 = approx 100 watts each@12.5 volts

Ameritron`s ALS 500 that uses 4 2879`s is rated at 400 watts CW@14 volts DC.
( I am not talking about clean, just power ratings here, because in all reality the 2879`s look best ( IMD wise) at approx 55 to 65 watts output)
If you take the average truck charging at @13.8/14 volts the avg readings are not that astronomical.
The peak readings are eye candy.

Will 4 2879`s do 1KW peak ?
Sure, at high voltage, with very dirty output, and outrageously high drive they will, for a little while.

73
Jeff