Back ~ 2000, I was using 77 material vs. 43 material for Ferrite chokes and I constructed an impedance table by freq.to determined how many beads I should use on each band. Now we talk about and use
I'm sure K9YC, who knows at least 20 dB more on the subject that I do, will have a more thorough explanation but basically the reason is that Type 31 material has desirable loss at HF frequencies ins
Here is an interesting article: http://www.karinya.net/g3txq/chokes/ \Svend, OZ7UV _______________________________________________ _______________________________________________ TowerTalk mailing li
Thank you Dave and Svend! 73 Bob KQ2M Here is an interesting article: http://www.karinya.net/g3txq/chokes/ \Svend, OZ7UV søn. 27. okt. 2019 21.32 skrev David Gilbert <xdavid@cis-broadband.com>: _____
Yes, but virtually all of the recommendations for #43 and #52 material are WRONG! The problem is not his measurements, but rather the wide tolerances of Fair-Rite components combined with the relativ
On 10/27/2019 1:31 PM, David Gilbert wrote: I'm sure K9YC, who knows at least 20 dB more on the subject that I do, will have a more thorough explanation but basically the reason is that Type 31 mater
Never the less he gets more than 8 kohm resistive impedance in a large frequency range using 52... \Svend Sendt fra min OnePlus One _______________________________________________ ___________________
Author: Roger Parsons via TowerTalk <towertalk@contesting.com>
Date: Wed, 30 Oct 2019 13:43:22 +0000 (UTC)
"Yes, but virtually all of the recommendations for #43 and #52 material are WRONG!" Steve is sadly no longer with us and unable to defend himself. However, he had previously rigorously defended his m
"Yes, but virtually all of the recommendations for #43 and #52 material are WRONG!" Steve is sadly no longer with us and unable to defend himself. However, he had previously rigorously defended his m
I was once trying to design a conducted power line EMI filter that had to have a lot of attenuation at one frequency around 100 kHz, and the power level was several kW. I needed a rather huge expensi
Many (many) years ago I was a component engineer at Collins Radio with responsibility for passive components, including ferrite cores. I was told by the core vendor that fabricating them was best li
Author: Roger Parsons via TowerTalk <towertalk@contesting.com>
Date: Sat, 2 Nov 2019 01:40:11 +0000 (UTC)
<The thing he missed, and that I also missed until recently, is the effect of component tolerances. > Sorry for the delay in responding - I was away. I was aware around 40 years ago that certain (but
You have a vivid imagination. :) I have measured data to prove that. Also see N6RK's post. As luck would have it, I gave a talk to a Silicon Valley club tonight on a very different topic, but afterwa
Author: Roger Parsons via TowerTalk <towertalk@contesting.com>
Date: Sat, 2 Nov 2019 13:25:19 +0000 (UTC)
Very funny. The posts from both N6RK and AB7E support my statement that variability in ferrite parameters has been known for a very long time. You're the one who asserted that it has just been discov
You have a vivid imagination. :) I have measured data to prove that. Also see N6RK's post. As luck would have it, I gave a talk to a Silicon Valley club tonight on a very different topic, but afterwa
<Very funny. <The posts from both N6RK and AB7E support my statement that variability in ferrite parameters has been known for a very long time. You're the one who asserted that it has just been disc
On 11/2/19 10:18 AM, Jim Thomson wrote: Date: Sat, 2 Nov 2019 13:25:19 +0000 (UTC) From: Roger Parsons <ve3zi@yahoo.com> To: "Tower and HF Antenna Construction Topics." <towertalk@contesting.com>, "j
I find that kind of China bashing pretty funny. Ridiculous as a generalization. I worked for a large semiconductor manufacturer for over thirty years and we ended up putting a joint venture manufact
Author: Jack Brindle via TowerTalk <towertalk@contesting.com>
Date: Sat, 2 Nov 2019 13:48:13 -0700
Sadly, there is much evidence. Fair-rite quality really took a hit after they moved production to Asia. So much so that many companies have had to institute new QA procedures on incoming product to s
Well, if that's the case it means that Fair-Rite did a poor job of transferring the manufacturing, and yes ... I've seen a bunch of other companies do the same crappy job of it especially when all th