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What ever happened to those palomar mosfets.

These divices are not as linear as the npn transistors and it depends on the mosfet you chose which will give you a higher rate of gain.

They do sound good on ssb.
 
seedkey said:
They use FQP9N15 mosfets 8 of them. I see a little over 300 watts out of mine with Cobra 29, with my Uniden grant I get around 250 watts. These amps are audio monsters and like to swing. They have a wide range like key 40 and swing 250 if you want to do that.
I wish the write Switchkit did on this board hadn't got lost.
Switchkit do you have a copy of the writeup you did?
Click to expand...

Id Say Seedkey is not driving his very hard . longivity would be the key here. 8 x Fairchild FQP9N15 . 40 amp "max" hence "max" I'D guess you would have to drive it to the 45 watts pep for that ? Should do around 30 amps.

Was told these amps like big volts as well. (IM really not up on that part ?) FQP9N15 Datasheet pdf - 150V N-Channel MOSFET - Fairchild Semiconductor I still have a couple of these. (Hey Linearone ? You out there somewhere ? This should look very familure to you , last I recall , you had half this amp. (-: )
palmosfet450insidehl9.jpg
 
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if you put this amp on 30+ volts you will see some downright magical watts. trust me on this. just figure a way to regulate the led's, keying circuit, relay, change the electrolytics and ceramic caps to 50v units and boom big watt amp for cheap...
 
linearone said:
if you put this amp on 30+ volts you will see some downright magical watts. trust me on this. just figure a way to regulate the led's, keying circuit, relay, change the electrolytics and ceramic caps to 50v units and boom big watt amp for cheap...
Click to expand...

Thats true, the irf520 will handle 100volts.
But it can only dissipate 60 watts of (heat) power.
compare that with a 2sc2879 rated at 250 watts maximum power dissipation.

Those dissipation ratings drop when it gets hotter.
 
hey switch, those fets you posted the link to come in a to220 package which is different to what we see in the 450,
have you lifted the small board to see what is actually in there or are you just going on what you have been told?
 
words from the maker Bob , unless I got side tracked when he told me ? The 250 , 450 and 800 are pretty much the same "boards" together.
 
There are 2 versions of that FET one has a all plastic back and the other is the standard metal back.
FQPF9N15
FQP9N15
Hope this helps
 
Switch Kit said:
Id Say Seedkey is not driving his very hard . longivity would be the key here. 8 x Fairchild FQP9N15 . 40 amp "max" hence "max" I'D guess you would have to drive it to the 45 watts pep for that ? Should do around 30 amps.

Was told these amps like big volts as well. (IM really not up on that part ?) FQP9N15 Datasheet pdf - 150V N-Channel MOSFET - Fairchild Semiconductor I still have a couple of these. (Hey Linearone ? You out there somewhere ? This should look very familure to you , last I recall , you had half this amp. (-: )
palmosfet450insidehl9.jpg
Click to expand...



What solder jockey assembled this thing? is this what they used?----->
solderladle.jpg
 
The FQP9N15 is no longer manufactured.

They do make the FQP13N10L, but its input capacitance is too high to be usable at 27MHz.
They have other parts with lower capacitance, but not handling the power.

Its probably best to stick with International Rectifier for this type of thing.
 

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