Suggested Mod of T2 for Efficiency Improvement

jpmiller
 

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Joined: 15 Dec 2022, 22:24

Re: Suggested Mod of T2 for Efficiency Improvement

Post by jpmiller »

DL2MAN wrote: 10 Jun 2022, 08:28
DL1GKC wrote: 04 Jun 2022, 16:29 *Rxxxx* recently published a document dealing with the efficiency issue in their kits. They recommend a different approach for T1/T2, by using a thicker 0,7 - 0,9mm wire as primary that must be placed in the center. Has anybody tried this approach?

I have modified my T2 to the 3/21 winding (0,35mm wire) but I do not see an increase of the displayed efficiency (average is 64%). At least the reflected power / SWR measurements are now working accurately in my kit (*Rxxxx* B3).
I have seen that *Rxxxx* Document, and I disagree with the value of it, as it´s mostly repeating my Instructions and adding some good practice, so it´s kind of pointless.
However, there´s some real disagreements from my side:
I disagree with Chapter 2 of Step 1: take special care for C11/C14/C19/C32 which have viases in their SMT pads and cover the pads with solder / make sure you realise proper solder joints.
I agree with you. I advocated for years at a major PC manufacturer, not so much for compact routing but to shorten the inductive path to a ground plane for bypass capacitors. I finally got manufacturing to do some test boards with some 10,000 capacitors from 1206 to 0402. Not a single connection failed. Although solder did flow into the vias no component had insufficient solder or lacked a proper fillet. No components "tombstoned" (one end standing up) and none were misplaced on the pads. The only remaining objection was that the vias could not be inspected on component side. I was allowed to design in vias-in-pads but few others did. That was over 20 years ago. Smaller components were not tested. W5PZT.
vk2tty
 

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Re: Suggested Mod of T2 for Efficiency Improvement

Post by vk2tty »

DL2MAN wrote: 13 May 2022, 15:19 I used 0,36mm Wire, as 0,4mm Wire would end up too tight
DL2MAN wasn't kidding :)
IMG_3388@0.5x.png
IMG_3388@0.5x.png (151.31 KiB) Viewed 1057 times
It'd help if UpTech and other suppliers shipping documentation with the new 3:21 advice also included lighter wire.

What's the smallest gauge we can use? The next size down available to me locally is 0.315mm.
DL2MAN
 

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Re: Suggested Mod of T2 for Efficiency Improvement

Post by DL2MAN »

That'll work just fine

73 Manuel DL2MAN
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