Help selecting and purchasing toroids

[VK7ZA]

Sometimes the internet is great because there's lots of information, and sometimes it's painful because there's lots of information. When it comes to selecting and purchasing toroids I've done so much research and reading, yet I can't see the wood for the trees. As such, I've got some specific questions that will either complete my knowledge , or at least set me on the correct track for further research.

I want to build some current baluns and LC networks for HF (10m in this case). I would appreciate answers that explain:
1. What I need
2. How you know that's what I need. As in what part of the specification makes that the one I need, so the next time I can work this out for myself.
3. Would this change if I were to use them for 6/20/40m, or do they cover most of the HF range of frequencies?
4. Where do buy your toroids from?
5. And finally, if you had no toroids, would you buy a range of types/values to have on hand? If so, which ones?


Thanks for any help that you can offer.

Lance

[VK5BC]

Hi Lance

I'm no expert on ferrites but recently I was sent this url.

http://www.mouser.com/ds/2/223/28A0807-0A2-599553.pdf

These are evidently special Nickel-Zinc (NiZn) ferrites recommended for use close up to the feed point on 2m.

73's Brian
VK5BC

[VK5TM]

I'm not an expert either, but the best advice I can give is to get a copy of:

Amidon - Transmission Line Transformers Handbook by Jerry Sevick

All (well 99%) of the information you ask about is in there.

As to where to buy, some have used Jaycar ferrites, Mini-kits in Adelaide carry some and a good range is on an american site at good prices (unfortunately, the brain is having a brain fart and I can't think of the name at the moment).

Ok, better now, american site is:

http://www.kitsandparts.com/