Not sure why I'm here.? I guess its because I like tubes.
How do you make those circiut boards anyway. Do you cut them with a dremel tool.?
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2x2sc2879 amp construction project
- Thread starter Moleculo
- Start date
Not sure why I'm here.? I guess its because I like tubes.
How do you make those circiut boards anyway. Do you cut them with a dremel tool.?
Making the circuit boards seems like half the project, I guess you could have good luck etching as long as you have a good pattern.
Your right tubes are not mobil friendly, but their's nothing better than a pair of 572's or 4-811A's just pushing away.
One thing to consider when your building transistor amps is buying the matched pairs or matched quads, I know an even output in paralled stages makes for a good running amp. I wonder if those AMP BUILDERS offer this option at all.?
Your right tubes are not mobil friendly, but their's nothing better than a pair of 572's or 4-811A's just pushing away.
One thing to consider when your building transistor amps is buying the matched pairs or matched quads, I know an even output in paralled stages makes for a good running amp. I wonder if those AMP BUILDERS offer this option at all.?
It has been my experience if the matched sets are not as important as some think. Ask the major builders and I think the concensus will be the same.
Now as far as transistors I feel that mosfets will be the way to go in a few years and I really like a mosfet mobile amps I built but you need a SMPS(Switch Mode Power Supply) or other means of powering it.
As far as etching I even tryed a pattern cut out of rubber layed on a copper board and sand blast it with a fine sand. Did not do to bad but not what I was wanting at that time.
Now as far as transistors I feel that mosfets will be the way to go in a few years and I really like a mosfet mobile amps I built but you need a SMPS(Switch Mode Power Supply) or other means of powering it.
As far as etching I even tryed a pattern cut out of rubber layed on a copper board and sand blast it with a fine sand. Did not do to bad but not what I was wanting at that time.
I was reading the parts list. It is lacking some key parts for a Quality amp. Instead of copying other class c amplifiers why don't we do something different? Let use a 5 pole Chebyshev LowPass filter. for attenuation of 2nd harmonics and up
-60 db. attenuation to 500 watts. What do you think Moleculo?
-60 db. attenuation to 500 watts. What do you think Moleculo?
2-pill amp
well for the class C amp...there is the 43 mix core with the 3 wraps of 16 awg teflon wire going from input transformer to ground...thats filtered there...and the + wire is filtered as well...
But the big thing is the +/- separation....If you know what that is...That makes a BIG difference in its self...If you want filtering in an amp...dont go with a class C amp...it dosent really go hand in hand...
*A class B Biased amp is nothing more than your able to run less deadkey drive into the amp to get the same amount out as compared to a class C Biased amp...
****For our AB Biased amps..there is plenty of filtering in those...and chokes..say..0 voltage untill you key the amp???
AM POWER
well for the class C amp...there is the 43 mix core with the 3 wraps of 16 awg teflon wire going from input transformer to ground...thats filtered there...and the + wire is filtered as well...
But the big thing is the +/- separation....If you know what that is...That makes a BIG difference in its self...If you want filtering in an amp...dont go with a class C amp...it dosent really go hand in hand...
*A class B Biased amp is nothing more than your able to run less deadkey drive into the amp to get the same amount out as compared to a class C Biased amp...
****For our AB Biased amps..there is plenty of filtering in those...and chokes..say..0 voltage untill you key the amp???
AM POWER
Northstar is talking about harmonics filtering, not bypass caps or wound torroids to isolate RF from DC (or vice-versa) within the amp.
I think it would be cool to start with basics, build a basic class C box, then change things up....have someone add in a bias circuit, then add low pass filtering design, etc, etc.
I think it would be cool to start with basics, build a basic class C box, then change things up....have someone add in a bias circuit, then add low pass filtering design, etc, etc.
You can also filter the harmonics on a class C amp just might take a few more components(or poles if you will) to attune them.
Like mole is saying it would not take much adjusting to convert a class c to ab. Just add the regulation unit and adjust tuning for the phase shift.
Like mole is saying it would not take much adjusting to convert a class c to ab. Just add the regulation unit and adjust tuning for the phase shift.
rlnthndr........
you can build a reliable spectrum analyzer using an old 40 channel radio with a working receiver section, a simple dc scope and a solid state ramp generator, resulting in 6 khz. of resolution. more expensive commercial units seldom offer less than 10 khz. of resolution. comes in handy for looking at the wasted power and trash generated by a pair of 2879's doing 450 watts.
i have built two of them to date with excellent results. if you need a pre-built ramp generator just follow the "Home" link to the main page of the site and email me by clicking on one of the mailboxes.
http://www.firecommunications.com/tech/analyzer.html
i also have a screenshot of the 10 pole chebyshev low-pass filter
i designed if anyone wants to try building their own for a new or pre-existing amplifier. software is available for download.
http://www.firecommunications.com/ScreenHunter_062.gif
well designed amplifiers use low pass filtering in the pa output.
check out the bottom half of the rf deck in this one............
http://www.firecommunications.com/images/1200.jpg
those are 8, 48VDC., MRF150's, 150 Watt (clean watts) N-Channel Enhancement Mode MosFET's you're looking at there on the top half of the deck. MosFET's aren't in the future, they're here. they've been here since the 80's.
you can build a reliable spectrum analyzer using an old 40 channel radio with a working receiver section, a simple dc scope and a solid state ramp generator, resulting in 6 khz. of resolution. more expensive commercial units seldom offer less than 10 khz. of resolution. comes in handy for looking at the wasted power and trash generated by a pair of 2879's doing 450 watts.
i have built two of them to date with excellent results. if you need a pre-built ramp generator just follow the "Home" link to the main page of the site and email me by clicking on one of the mailboxes.
http://www.firecommunications.com/tech/analyzer.html
i also have a screenshot of the 10 pole chebyshev low-pass filter
i designed if anyone wants to try building their own for a new or pre-existing amplifier. software is available for download.
http://www.firecommunications.com/ScreenHunter_062.gif
well designed amplifiers use low pass filtering in the pa output.
check out the bottom half of the rf deck in this one............
http://www.firecommunications.com/images/1200.jpg
those are 8, 48VDC., MRF150's, 150 Watt (clean watts) N-Channel Enhancement Mode MosFET's you're looking at there on the top half of the deck. MosFET's aren't in the future, they're here. they've been here since the 80's.
Yeah I have to agree on the mosfets. They seem to be the way to go especially if you are on a base setup. As far as mobile the power supply has to be worked out, not that it would be hard just means using a SMPS or relays to series and parallel the batteries to get the 48V or 50 that they like.
As far as the spec analyzer the poormans spetrum analyzer built for use on an oscilliscope works decent from what I have been told. I never took the time to mess with it, I just used a radio shops when needed but now there gone so.......
As far as the spec analyzer the poormans spetrum analyzer built for use on an oscilliscope works decent from what I have been told. I never took the time to mess with it, I just used a radio shops when needed but now there gone so.......
N
nvcowboy25
Guest
well i just got most of my parts, i need a few more for the AB biasing circuit, and still undecided if its going to have an output filter, drilling the board and heatsink is gonna be a pain with the tools i have, is anybody else here having a go at this???.
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