The amp will only do 1000 watts peak if you drive the snot out of it.....plus the install has to be perfect.
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X-Force XT-400 2x4 (6 Pill) Pill Driver
- Thread starter Primetime17
- Start date
The amp will only do 1000 watts peak if you drive the snot out of it.....plus the install has to be perfect.
Everyone of my 2x4 amps will make 1000 watts pep with 15 watts pep no sweat at roughly 14 volts.
That makes me question if them there are 1000 Bird 43P watts into a 50 ohm load? I don't doubt for a second that four 2SC2879's can make 1 KW PEP. The problem is doing it with a 14 volt source even assuming the amp is biased deep into class C.
Having too much drive isn't going to make the finals produce more output once they hit saturation. Considering the voltage drop between the source and the collectors, you are going to exceed the maximum current on the transistors before you reach the 1 KW PEP.
Having too much drive isn't going to make the finals produce more output once they hit saturation. Considering the voltage drop between the source and the collectors, you are going to exceed the maximum current on the transistors before you reach the 1 KW PEP.
You're forgetting that "CB watts" = 27MHz watts + harmonic watts + splatter watts + extra reading from antenna reflecting all that harmonics back. Then you get a kilowatts from four pills.
I put a Texas Star 667 in my truck and key with modulation then take it out and install a 2x4 comp amp and the receiving station notices a 1/2 s unit increase in signal. Something tells me it ain't all harmonics like the Hammers think.
I am getting amused at all this false information. Your power supply is doing 20 volts at no load......key the amp and check the voltage with an analog meter and surprise, surprise the voltage will drop to 14-15 volts and that is the way it works.
There is no freaking way on earth a properly driven comp 4 pill on 20 volts will swing less than 1400 watts peak on a Dosy.....more like 1600 watts peak.
If these unregulated power supplies held 20 volts during transmit, the landfills would be full of blown 2SC2879s. Please don't PM with yet another warning for being argumentative because you are just dead wrong on this one.
My base amp is a 2x2290 driving 8x2879 and the supply has been floating at 19.5-20.1 since I bought it from Worldwide and when keyed the supply voltage drops to between 14.2-14.6 volts.
The only possible way your supply could be holding 20+ volts during transmit is if you are running a 1000+ amp unregulated supply for your 4 pill. And don't check voltage during transmit with a digital meter...only analog.
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YMMV Psycho you are correct that it will not hold that under load, when I had it it would float at around 22 volts and under load it would drop to just about 19 volts.
It was a x force 400-12 base Amp .
The watt meter was my old beat up rat shack so I am not talking about peak watts.
After I won the amp in the DX contest I talked to Frank one day and he told me I could switch the power supply leads off of the secondary's on the transformers for the higher voltage. If you remember this is the 400-12 that Carl built for the forum for one of the CDX contests.
I am sure that it would show higher numbers out as you said on a peak meter...but not the one I use. It also ate bridge rectifires with a steady diet.....there were some flaws with the way it was built it had huge filtering ( large caps) that cause massive inrush current when switched on amoung other things.
I will say that x force did send replacment B/R's but I finally gutted it and used amp section for a mobile, still have the case in storage because I planed to use the parts to build a regulated supply with it but never got around to it.
And I still stand by the statement that if you want a relaiable KW mobile you need double the transistor's. Yes 4 2879's will do a KW but if you screw up you are gonna replace transistors. And it is a hassle to volt a mobile when you could do it with 13.8 or 14 and less stress
73
Jeff
It was a x force 400-12 base Amp .
The watt meter was my old beat up rat shack so I am not talking about peak watts.
After I won the amp in the DX contest I talked to Frank one day and he told me I could switch the power supply leads off of the secondary's on the transformers for the higher voltage. If you remember this is the 400-12 that Carl built for the forum for one of the CDX contests.
I am sure that it would show higher numbers out as you said on a peak meter...but not the one I use. It also ate bridge rectifires with a steady diet.....there were some flaws with the way it was built it had huge filtering ( large caps) that cause massive inrush current when switched on amoung other things.
I will say that x force did send replacment B/R's but I finally gutted it and used amp section for a mobile, still have the case in storage because I planed to use the parts to build a regulated supply with it but never got around to it.
And I still stand by the statement that if you want a relaiable KW mobile you need double the transistor's. Yes 4 2879's will do a KW but if you screw up you are gonna replace transistors. And it is a hassle to volt a mobile when you could do it with 13.8 or 14 and less stress
73
Jeff
AMPLIFICATORE LINEARE CB THE KING BY MICIO 4000 ++WATT | eBay
here's one that might do the power requested. it says 28volt but it might work on less.
here's one that might do the power requested. it says 28volt but it might work on less.
B
BOOTY MONSTER
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1kw is no problem from a (2) 2290 drv (4) 2879. Here is a 2x4 i built doing 625 avg and 1450 watts peak on the bird, driven by a HR2510. Volts under load was steady at 15 regulated. No BS here, check the video.
waterbug built (2) 2879 drv x(4) 2879 @ 15 volts - YouTube
It can be done (1kw peak). Like another poster said, you need a radio that "swings".
The HR2510 was doing about 2 watts dk and swinging 50 peak (bird).
Yes thats a lot of drive going into the variable, (variable was wide open) but hey...we are cbers. We love overdriving stuff and seeing that meter "swang". LOL!
waterbug built (2) 2879 drv x(4) 2879 @ 15 volts - YouTube
It can be done (1kw peak). Like another poster said, you need a radio that "swings".
The HR2510 was doing about 2 watts dk and swinging 50 peak (bird).
Yes thats a lot of drive going into the variable, (variable was wide open) but hey...we are cbers. We love overdriving stuff and seeing that meter "swang". LOL!
I would love to see what ohms your dummy load is showing with that tuning circuit attached.
Never said that 4 2879's are not able to do a kw....and as that vid shows they will.
Guys at keydows are getting more (peak) with more volts
Peak...on the bench....drivin hard or in a key down drivin hard volted.
Most everyday cb'ers will be replacing transistors by the handfull with a 2x4 run that hard because they have seen someone do it in a video on a bench.
If you do not have all your ducks in a row...as in very carefully watching reflect it is going to happen.
If you run a 8 pill at stock volts with much less drive you can achive the same numbers with much more headroom and a much bigger margin of safety as far the life of the amp.
A 2x4 amp is running on the edge all the time....if you have a radio with a variable power control and you forget to turn it down....... ten ohm smoke.
A lot of these guys go to a web site and see these amps listed doing 1000~1200 watts and think damn I am gonna get one...they pay...it gets home they bolt it in there ford pinto and it only does 450 500 watts on there everyday meter..they crank up the drive and poof.
73
Jeff
Guys at keydows are getting more (peak) with more volts
Peak...on the bench....drivin hard or in a key down drivin hard volted.
Most everyday cb'ers will be replacing transistors by the handfull with a 2x4 run that hard because they have seen someone do it in a video on a bench.
If you do not have all your ducks in a row...as in very carefully watching reflect it is going to happen.
If you run a 8 pill at stock volts with much less drive you can achive the same numbers with much more headroom and a much bigger margin of safety as far the life of the amp.
A 2x4 amp is running on the edge all the time....if you have a radio with a variable power control and you forget to turn it down....... ten ohm smoke.
A lot of these guys go to a web site and see these amps listed doing 1000~1200 watts and think damn I am gonna get one...they pay...it gets home they bolt it in there ford pinto and it only does 450 500 watts on there everyday meter..they crank up the drive and poof.
73
Jeff
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I would love to see what ohms your dummy load is showing with that tuning circuit attached.
Mack,
50 ohm dummy load (too bad that vid does not show the dummy load but my other vids on the same bench do).
No tricks, bs. That was a straight up no hockus pokus what you see is what you get vid.
Also, no bs slug tampering either. (LOL slug tampering) Yes sad but true some people will really do that.
Pump.
Agreed. Well said. I just shake my head with the "FU" version which is (2) 2879's driving (4) 2879's. It can be done, It has been done, but that FU version box is NOT for the average joe to run... Personally, I have been asked to build these but each time I have refused to do so.
And as you stated in the latest video you're driving that driver stage with 50+ watts and as we all know that is more than sufficient to drive the output stage to it's full potential and more than 600 watt pep from that amp is just junk.
Albeit a true reading on bird meter it is none the less crap output at 1450 watts pep.
I am not impressed.
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