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Author Topic: CLASS D or CLASS E: Which One Should I Choose  (Read 9051 times)
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W1KSZ
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« on: April 12, 2018, 09:43:25 PM »

I am getting more serious about building a Class D or E AM Transmitter, something in the 300 Watt avg range.

Before I can get started, I need to decide which Class to build, D or E.

What are the advantages of one over the other ? Which one should I choose and why ?

Also, after deciding, I will need a source of DIY info, schematics, pictures, etc.

Thanks for your help,

73, Dick, W1KSZ
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W1KSZ
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« Reply #1 on: April 12, 2018, 09:47:33 PM »

My bad guys, I forgot I had a similar question earlier. Old age is a ^&*%*&.

73, Dick, W1KSZ
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W2PFY
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« Reply #2 on: April 13, 2018, 09:58:54 AM »

I don't know a source for class D but Steve WA1QIX has about all could want for your edification.


http://www.classeradio.com/
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The secrecy of my job prevents me from knowing what I am doing.
M0VRF
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« Reply #3 on: April 13, 2018, 03:04:32 PM »

I use Class D/E or that's what I think it is has class E waveforms with class D B/W = >1MHz on 40m.

If you stick to the design by VE3ELQ using the SiC FETs from Cree you'll be fine.

My version uses 4 GaN Fets and runs 100W carrier with 500W peaks with a 48V PSU.

Pic attached.



* tx.png (305.81 KB, 1028x703 - viewed 1041 times.)
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n1ps
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websdr http://sebagolakesdr.us:8901/


« Reply #4 on: April 15, 2018, 08:14:05 PM »

For Class E, go with the QIX designs.  Bulletproof and probably more than 100 have been built.  Steve gives you complete designs including the modulator (PWM) and even a VFO.

For Class D you can also look at Jay W1VD site.  He has some nice designs.  He recommends the QIX PWM I believe.

Either way these projects are intensive and take time  Wink.  I think it took me about a year to put together a class E project.  But well worth the effort IMHO.

Peter

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steve_qix
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« Reply #5 on: April 15, 2018, 09:10:03 PM »

It is possible to build a complete transmitter from the ground up, in about a month.  But of course it won't be a pretty as the one Pete (N1PS) built  Wink
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High Power, Broadcast Audio and Low Cost?  Check out the class E web site at: http://www.classeradio.org
KF1Z
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Are FETs supposed to glow like that?


« Reply #6 on: April 17, 2018, 11:13:03 AM »

I noticed your post in "Wanted".
.
If you can populate a PC board, you can pretty likely build Steve's design.

A lot of folks have built these successfully with 'limited' skills.

Doesn't matter what the end product looks like, only matters that it works :-)

If there are certain parts that you decide you can't, or don't want to attempt, there are a few people around who can help you out as well.
Either by advice here, by email, or even putting together parts for you.

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steve_qix
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« Reply #7 on: April 17, 2018, 08:49:25 PM »

I noticed your post in "Wanted".
.
If you can populate a PC board, you can pretty likely build Steve's design.

A lot of folks have built these successfully with 'limited' skills.

Doesn't matter what the end product looks like, only matters that it works :-)

If there are certain parts that you decide you can't, or don't want to attempt, there are a few people around who can help you out as well.
Either by advice here, by email, or even putting together parts for you.



Holy Missing Person, Batman !!  Wow, Bruce - it's been FOREVER !!! What's going on?  Send me an email (I still have the same one I've had for 20 years).

Good to see you're still interested.

Regards,  Steve
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High Power, Broadcast Audio and Low Cost?  Check out the class E web site at: http://www.classeradio.org
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