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New 80M TX Module




 
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September 19, 2019, 09:53:48 PM *
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Author Topic: New 80M TX Module  (Read 1579 times)
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vk3alk
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« on: September 16, 2018, 06:44:57 AM »

Decided to upgrade my current TX module.
It uses 2 H Bridge Modules into a Magic T Combiner with the usual 5:7 turn impedance transformer.

Goes well ... not surprised its called MAGIC..... Cheesy

The testing has only been made at low power but all seems good so will mount it in the transmitter box soon...
These modules have been tested at 200 watts so combined would be a nice Legal Limit transmitter over there......

Probably the most important thing is that both modules are very similar in performance....


Wayne




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ka1tdq
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« Reply #1 on: September 16, 2018, 08:51:48 AM »

Hey Wayne,

Looks great! Kudos to you too on the workmanship. Half the battle is neatness with this stuff.

Would you be willing to post of the schematic of the modules and combiner? There are published schematics for full power class E stuff, but not too much for class D. I know of one class D schematic on another website which uses analog drive and is also an H-bridge. It would be nice to have more options available for people.

I'm stuck in E-mode if for nothing more than cosmetics. Adding a strapping cap and inductor can add a secret military weapon look to the transmitter. The coolness factor is there.

Jon
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Just follow the instructions, more or less.
http://www.ka1tdq.radio
VE3ELQ
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« Reply #2 on: September 16, 2018, 04:23:48 PM »

Good work Wayne looks very nice.  If it modulates OK to full PEP it should do well on the air. Great to see others building and experimenting.  Please keep us updated as your testing progresses.  What FETs are you using??

73s  Nigel

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vk3alk
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« Reply #3 on: September 17, 2018, 01:59:35 AM »

Hi Jon and Nigel...

Thanks for all your comments.....

The TX module is going fine running at 93% efficiency and that's post filter.....
Although not tested at higher power levels will install sometime this week ...... there is not much room so may have to reduce the size of the combiner a bit but that's easy enough.....

Class E fine .... must admit the output coil makes it look good .....

The FETs are IPP530N15N from Infineon...

The magic T is here https://www.w8ji.com/combiner_and_splitters.htm


Wayne
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