The other day, just for fun, I swept a bunch of ol' RF chokes -- solenoid wound, pie wound, etc. All of them exhibited nasty resonances somewhere within the HF spectrum. I then wound a few experiment
If avoiding saturation is the point, how about using a ferrite rod instead of a toroid? Or using a toroid but cutting a small gap into it (with an abrasive disc)? Angel Vilaseca HB9SLV Radio WC6W a é
Hi Hardy, True... but, the DC will "kill" the core at HF. Look at the bottom of page 129 on this link http://fair-rite.com/newfair/pdf/CUP%20Paper.pdf to see the ... damage. And operating on the curv
Hi Angel, The point was to make a rather high value (1-2mHy) choke with no resonances in the HF region. The saturation gotcha was a by-product. A rod wouldn't suffice in this application. A gapped co
What about this theory? See the lower part of the page. http://www.kk5dr.com/chokes.htm 73 Jim W7RY _______________________________________________ Amps mailing list Amps@contesting.com http://lists.
Marv & all, Just some random thoughts which may or may not be appropriate/valid: Why 1-2 mH? Just curious because if I had a choke design that was 250-300 MICRO H and didn't have any resonances below
If you want a good laugh read thru all his "ideas" Carl KM1H _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
There was an article in HRM in the early 80's showing a 5kw rated choke with a rod. I tried several iterations and all smoked at some frequency at 1200W. The subject came up again on here, I believe,
No one appears to have addressed my original query re: servo cancelling the DC in a toroid core. Rather wandering back to the general plate choke topic... So, I'll wander a bit too! While experimenti
Marv, You need a push pull choke. :>) Maybe a second winding that loops back on the core and is in series with the choke winding. But I don't think that the DC current is the whole problem with ferri
ORIGINAL MESSAGE: REPLY: Beware of anything KK5DR says. The guy is incompetent when it comes to electronic design. I have chosen my words carefully. 73, Bill W6WRT ___________________________________
As Karl says, it is entertaining though. 73 Gary K4FMX _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
Hi Jim, That is actually old knowledge. See the bottom of this page on my site: http://wc6w.50webs.com/wc6wamps/index.html?fr62.html And it can't produce a mHy range coil sans resonances. 73 & Good m
Hi Larry, So that the choke still behaves as a choke down on 160 rather than becoming a significant portion of the plate circuit. 73 & Good morning, Marv WC6W http://wc6w.50webs.com/ ________________
Hi Gary, A second winding in series that cancels the DC would also cancel the AC rendering the part... useless. A second winding with only DC is indicated, and with minimal coupling to the main windi
Hi Jim, To my knowledge, rods are not made (as standard parts) in 43... a few cable cores could be stacked. Rod cores don't have anywhere near the effective mu of a toroid. Because of the open magnet
Author: "Dr. David Kirkby" <david.kirkby@onetel.net>
Date: Sat, 16 Jan 2010 12:38:28 +0000
Having looked over KK5DR's site, it would appear that all pages should be linked under: http://www.kk5dr.com/stories.htm I too have chosen my words carefully! Dave G8wRB _____________________________