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Homebrew and Kit Projects

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KF5GOI Need some help on transformer winding mod on 220 vac powered
portable 225 Lincoln welder.

Posted: 02 Oct 2017 10:28 AM PDT
https://forums.qrz.com/index.php?thr...welder.583208/

Hello, unfortunately Im having a hard time locating some of my information
on transformer winding mods.

I have quite a few power supplies of all types.

I have more than enough weld machines that are very good for keeping them
as is .

The old Lincoln 225 I already have rectifiers that are built on heat sinks,
Also have plenty of large diodes. Lots of capacitors, etc.

I have built a number of amplifiers, tube and transistor.

The largest power supply that is complete and in use is a 100 amp...



KF5GOI Need some help on transformer winding mod on 220 vac powered
portable 225 Lincoln welder.

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Front end protection

Posted: 02 Oct 2017 07:59 AM PDT
https://forums.qrz.com/index.php?thr...ection.583203/

Im wanting to do a homebrew RX pre amp..

Trying to find out more about diode front end protection, BUT all I seem to
find googling is

generalities.

Any tips, links, math, rules of thumb Info on calculating inductors or
choosing pin diodes

to protect the amp input?

Thanks

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Power line filter?

Posted: 01 Oct 2017 05:29 PM PDT
https://forums.qrz.com/index.php?thr...filter.583144/

I have a HUGE problem with the big central inverters in my (well, actually,
my moms) solar power setup. As is common, they spew gigantic amounts of RF
into the house wiring, and directly into my shack. Ive been thinking of
building a AC line filter to make 40m usable again. I did some googling,
and Mouser sells EMI/RFI filters. Apparently I will need an inductor coil,
and heres where I get lost. A zillion different opinions on the type of
ferrite in the toroid, what wire to use, how many...



Power line filter?