Hi,Im confused regarding the choice of iron powder toroid for a 7Mhz high passfilter. I need to use a small size (T68) toroid. For the freq range, somereference texts say T68-2 is the one, others say T68-6" grade. I seediffering "best Q range" specs for the 6grade.....2-30Mhz......10-50Mhz...etc.Have similar need for 20Mhz LPF, but assume "6" is really the choice there.Any suggestions as to the relative differences and reasons to choose betweengrades 2 and 6 for the HPF in T68 size?Thanks,JEFF

As far as I know, 7MHz is on the border between using one mix or the other. You'll see different Q's because details of winding, wire choice and mounting will affect Q, as would use of a core from another manufacturer (I don't know if anyone other than MicroMetals uses that system, but if they did I wouldn't count on it being standardized).If you're not going to be hitting it with really high power and if you don't need it to be highly resonant I wouldn't worry too much. If you're going for an engineered solution then you should make a number of "identical" coils and test them; just make sure that the coils you make are representative of what you'll be manufacturing.-- Tim WescottWescott Design Services

Choice of iron powder toriod?

Oct 11, 2005 29 Replies

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Tim Williams 20 years ago

So, digital is base two, and analog is base 1.6 x 10^19? ;-)

Tim

-- Deep Fryer: a very philosophical monk. Website:

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Keith Williams 20 years ago

Not really. Analog's bits are just smaller. ;-)

Keith

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Graham W 20 years ago

Nah - 2102 1k * 1.

Had 8 of 'em in in my homebuilt Nascom 1 computer which with a

2708 UVEPROM for the 'monitor' was all the RAM for system and user code and video store! Nevertheless, it was sufficient for a machine code program to run 'Lunar Lander', hee hee.

Collins filters were regarded as the bees knees in UK ham circles but I never could afford one!

73 de G3VPC

Graham W http://www.gcw.org.uk/ PGM-FI page updated, Graphics Tutorial WIMBORNE http://www.wessex-astro-society.freeserve.co.uk/ Wessex Dorset UK Astro Society's Web pages, Info, Meeting Dates, Sites & Maps Change 'news' to 'sewn' in my Reply address to avoid my spam filter.

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Joerg 20 years ago

Hello Tim,

Still, the digital guys kept telling us "Some day we'll get there and then you are going to be extinct". I am not worried at all...

Regards, Joerg

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Pooh Bear 20 years ago

How long have they been saying that ???? ;-)

Graham

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Keith Williams 20 years ago

We've been getting half the way there every two years or so. ;-)

Keith

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Michael A. Terrell 20 years ago

That was one early memory chip i don't recall using.

The price was right, that day at the Dayton hamfest. ;-)

? Michael A. Terrell Central Florida

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Steve Nosko 20 years ago

Poor fella's got it bass ackward.

73, Steve, K,9;D.C'I

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Steve Nosko 20 years ago

That's what he said... 10^18 smaller

73, Steve, K,9.D;C'I

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Steve Nosko 20 years ago

Don-chya love it ? !

73, Steve, K9DCI

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