HFU HF Underground
Technical Topics => The RF Workbench => Topic started by: Stretchyman on November 08, 2015, 1118 UTC
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Latest incarnation from my bench, actually the kitchen table at the mo'!
A Push Pull class E design ANY frequency up to 8MHz.
Will work from 12V to whatever.
Keeping it sensible I'm getting 25W carrier at 12V and just under 100W at 24V.
Check out my MiNi PWM to the LHS, the filter sits on top, will mod 200W!
I've only got 3 PCB's made, want one built up? let me know.
Stretchy.
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Sounds like a winner!
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I'm working on something similar based on Current Mode Class D for MW and HF (different rigs of course). Initial tests prove promising, 48V peak supply (24V carrier) yields about 50W and a few hundred KHz of B/W. I like the efficiency too, around 93%. Should be able to scale this to the KW range.
+-RH
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Yep, well same rig really as Class D or E, are very similar and nothing to touch them for simplicity and efficiency.
Bye Bye class C!
The W1VD is the best design by far but for simplicity WA1QIX is hard to beat for 10% less efficiency but there are much better (cheap) devices around now.
What O/P's are you using BTW?
Have you 'Discovered' Cree yet?
:)
Stretchy :P
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Yup, playing with Cree here...
+-RH
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Got some 160's and now have some 3rd gen ones (C3M0065090D) so looking to fire 8 + 8 drivers (4 FET/Drivers per side) up @ 120V and see what happens.
I don't like the binocular sleeves and prefer big toroids, however at this power the T400-2D's aren't cheap.
The Gate C (Ciss) is spectacularly low for such a cheap device, if they work as well as I hope they will be nothing to touch them at that price.
Keep us posted.
Stretchy.
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I ran some simulation a while back, looks like a T400-2 output transformer in CMCD should handle 1KW carrier easily at 7 MHz. At 1.7 MHz though you need two of them stacked to get enough inductance.
+-RH
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OK they less than £20 each, reasonable I guess.
I have a PCB strip made for the FETs and the drivers, everything else will be off board.
Need to source a big heatsink to mount everything on then I can get to work.
:)