DRIVERS 2X 1446 VS 2X2290

[goofy]

the 2879 will go way over its nameplate capacity. It won't last long or sound good, but it can. That's why people can get 600w plus out of 4 transistors

[73_]

the 2879 will go way over its nameplate capacity. It won't last long or sound good, but it can. That's why people can get 600w plus out of 4 transistors

Yeah, and harmonically rich, too.

You notice they never use a low-pass filter before the meter. If they did I bet it would show about 450w out of the 600w they imagine they're getting on the band where they want it.

[Rooster173]

You mean people still use 1446 just kidding but def the 2290 is the superior final

[Rooster173]

I don't get it... I keep reading and hearing guys claim impossible numbers from the 2879 100w pep transistor. 450W from 2 2879s? How do you get a 100w pep transistor to output 225% of it's designed power output?

I can understand under rating, such as
6w in = 100w pep out
10w in = 165w pep out

But how do you force another 60w ABOVE MAX OUTPUT out of it?

Well one thing to consider is that this power output is rated at a certain voltage probably 13.8 the standard. People getting these numbers are usually running at a higher voltage closer to 17 or 18. Thus earning a higher power output. Also using radios that are peaked. Hope this helps. Rooster

[Rooster173]

the 2879 will go way over its nameplate capacity. It won't last long or sound good, but it can. That's why people can get 600w plus out of 4 transistors

When you say 600 plus i hope you are talking about rms. As far as peak goes its nothing to push 4x2879 with 2x2290s and see easily over 800 watts PEAK. And in most cases over 1000 if it is a relevant amp. Rooster

[73_]

Yeah, at 18v or 150% rated voltage of 12vdc @ 100w pep you should get about 165w pep, due to both the higher voltage (+50%) & higher efficiency (+10%) at that higher voltage.

4 x 165w pep = 660w pep @ 18vdc, but pep is double RMS so really, a set of 4 2879s @ 18vdc is only an honest 330w AM amp at no forward or reverse swing, but providing 660w pep. More if you don't mind overheating the transistors to get out of band harmonics which can make a watt meter read higher.

[Rooster173]

Yeah, at 18v or 150% rated voltage of 12vdc @ 100w pep you should get about 165w pep, due to both the higher voltage (+50%) & higher efficiency (+10%) at that higher voltage.

4 x 165w pep = 660w pep @ 18vdc, but pep is double RMS so really, a set of 4 2879s @ 18vdc is only an honest 330w AM amp at no forward or reverse swing, but providing 660w pep. More if you don't mind overheating the transistors to get out of band harmonics which can make a watt meter read higher.

665 watts undriven perhaps then throw in a pair of 2290s driving and you have a different story. 2879s are made to drive plain and simple my 16pill base wont do over 900 watts unless driven max i have seen driven power is 3500rms, it does rund on crazy voltage though somewhere around 20v

[73_]

So you're saying you're getting 3500w from 16 100w @ 12vdc transistors. So if you drive them even harder then they will put out even more, and then harder even more until you get 20KW from 16 2879s!!

Where does it end? Can I get 2,000hp from my Toyota Camry if I just put 1800 shot nitrous into it? Yeah, for about 50 feet them BOOM!

I don't consider destruction of a component a valid rating, but if all you care about is 10 seconds in a keydown competition (if you're lucky) then POP, OK, but 220% of rated design isn't something I'm prepared to accept as real for typical daily use. I'll question the meter every time.

[Rooster173]

So you're saying you're getting 3500w from 16 100w @ 12vdc transistors. So if you drive them even harder then they will put out even more, and then harder even more until you get 20KW from 16 2879s!!

Where does it end? Can I get 2,000hp from my Toyota Camry if I just put 1800 shot nitrous into it? Yeah, for about 50 feet them BOOM!

I don't consider destruction of a component a valid rating, but if all you care about is 10 seconds in a keydown competition (if you're lucky) then POP, OK, but 220% of rated design isn't something I'm prepared to accept as real for typical daily use. I'll question the meter every time.

Sorry if I confused you let me put it this way. 8 2290s will put out more than 8 2879s simply because the 2290s take less drive to get maximum output. As far as voltage goes i dont really recommend going over 17 volts. But running at seventeen volts can optimize your power output. My sixteen pill is used for constant local talking and i've owned it a little over five years with no trouble driving it with a 1x2290s driving 4x2879 amplifier. As long as you keep your deadkey reasonable problems are avoidable. Many people try to run a high deadkey it simply kills transistors. Usually i don't swing more than 800watts into the sixteen just fyi

[Rooster173]

So you're saying you're getting 3500w from 16 100w @ 12vdc transistors. So if you drive them even harder then they will put out even more, and then harder even more until you get 20KW from 16 2879s!!

Where does it end? Can I get 2,000hp from my Toyota Camry if I just put 1800 shot nitrous into it? Yeah, for about 50 feet them BOOM!

I don't consider destruction of a component a valid rating, but if all you care about is 10 seconds in a keydown competition (if you're lucky) then POP, OK, but 220% of rated design isn't something I'm prepared to accept as real for typical daily use. I'll question the meter every time.

As far as questioning the meter I buy a new meter every single year to ensure i have the tightest meter around. As i buy sell and trade a lot of radio equipment I try and keep it where people get home with equipment and are amazed when it does more at their house than it did mine. Thanks, Rooster

[-=PEAKABOO=-]

I don't get it... I keep reading and hearing guys claim impossible numbers from the 2879 100w pep transistor. 450W from 2 2879s? How do you get a 100w pep transistor to output 225% of it's designed power output?

I can understand under rating, such as
6w in = 100w pep out
10w in = 165w pep out

But how do you force another 60w ABOVE MAX OUTPUT out of it?

a 2879 will dissipate 250 watts. The ratings are to keep it friendly to other frequencies. At the cost of spurious energy you really can increase someones signal on you and jack off your watt meter all at once.

[73_]

Yeah, at least jack off your watt meter. That additional power output is on 6 meters and 3 meters and 1.5 meters and so on.

If it was a 225w transistor they would sell it as such and make more money. The real power of a 2879 maxes out at 65w AM and 135 pep on SSB if you have 16vdc going to it. More than that is distortion, harmonics and fried chicken.

[beavis018]

If you really want to be loud how about 1-2290 driving 2-2879's. X-200 would work nicely just keep the dead key around 250 or less over all and if be careful watch what your doing you could see 2200 to 2500 peak swing if your 8 pill is xforce and you have all the proper power supplies SWR ETC. I admit you would be running your 8 pill hard but you would be loud and it will last if your careful. Maybe even use a single final radio. If your looking for 100% Duty cycle out of your 8 pill 1-2290 will be suffecint.
73's
:r&r:

[MuskyHunter]

Holy batman, I can't believe what I'm reading here...... 1- 2879 is all you need to drive an 8 pill with a bone stock or slight tune on a uniden or cobra, anything more just makes your meter needle happy and isn't on freq. 2-2290 is also fine for the 8 pill with a 29 radio or single final. But hey if you just like to repair amps and watch **Censored** meter watts have at it. It just annoys the locals and no one in skip land will see any difference. To many thinkers here reading spec sheets for performance. Thats your first clue that you have no idea what your doing. If its such a great idea or the better way to do it, we should be seeing dual final radios driving at the keydown line, and the last thing they care about is a clean signal yet alone being on freq. If someone gives you flowers for an all 2879 1x2 amp they must be deaf or have one crappy speaker that they are used to. Try a low pass filter then see how many watts you have in the band.

I'd say stop where your at and do a months worth of reading before you buy, or am I too late. I got tired of reading all the ridiculous overdrive posts. Quickest way to wear out or replace transistors early. You'll find yourself getting alot more responses when your signal is cleaner, more legible than the rest.

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Sunday, 03 February 2013, 13:55 PM

Wow, dont I feel like a **Censored** posting on an ancient thread......

[-=PEAKABOO=-]

Yeah, at least jack off your watt meter. That additional power output is on 6 meters and 3 meters and 1.5 meters and so on.

If it was a 225w transistor they would sell it as such and make more money. The real power of a 2879 maxes out at 65w AM and 135 pep on SSB if you have 16vdc going to it. More than that is distortion, harmonics and fried chicken.

My spectrum analyzer tells a different story. Reread what I posted prior to your post.

[Ohio_359]

Comes down to it, they don't make the 2879 anymore either.

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Sunday, 02 June 2013, 20:15 PM

So you're saying you're getting 3500w from 16 100w @ 12vdc transistors. So if you drive them even harder then they will put out even more, and then harder even more until you get 20KW from 16 2879s!!

Where does it end? Can I get 2,000hp from my Toyota Camry if I just put 1800 shot nitrous into it? Yeah, for about 50 feet them BOOM!

I don't consider destruction of a component a valid rating, but if all you care about is 10 seconds in a keydown competition (if you're lucky) then POP, OK, but 220% of rated design isn't something I'm prepared to accept as real for typical daily use. I'll question the meter every time.

Sorry if I confused you let me put it this way. 8 2290s will put out more than 8 2879s simply because the 2290s take less drive to get maximum output. As far as voltage goes i dont really recommend going over 17 volts. But running at seventeen volts can optimize your power output. My sixteen pill is used for constant local talking and i've owned it a little over five years with no trouble driving it with a 1x2290s driving 4x2879 amplifier. As long as you keep your deadkey reasonable problems are avoidable. Many people try to run a high deadkey it simply kills transistors. Usually i don't swing more than 800watts into the sixteen just fyi

The 2290, or even the 1446 is higher gain, but that =/= higher output.

[Rabbit Ears]

Right now I'm fussing with a TWO pill amp with a pair of SD1446 Transistor finals. Not bad for a KL 300P... re-biased for AB operation.

You are right........ the 2290 is better for durability. A little bit more....

[Lost Ram]

Wow an old thread but what the heck.
I think some folks have a peak kit for their peak kit!!!!! My HD 6 pill on 18V dropping to 15V on key does an honest 700 watts with about 70 watts drive. I vote for the one 2290 or 2879 to drive the 8 2879's. Sure you could use two of the either but be sure its variable.
To many folks get hung up on the watt meter readings. They need to make a sounding good meter instead of a watt meter!!!! LOL.