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C-Core grid chokes [message #31584] Mon, 12 December 2005 18:55 Go to next message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
Hey-Hey!!!,
I just got the C-core gird chokes from Heyboer. Nice looking and right on spec.

With a small gap they run from 575 Hy to 600 Hy from .5 vac @ 60 cps to 40vac. The gap does its job just like it should, and there is plenty of inductance. About 30kOhm per half at 20 cps( 2Pi*20*(L/2)).

I plan to do full spectrum measurements on it soon. My Heathkit signal generator needs two 9V batteries, and I can't rob the smoke alarms anymore...:)

I plan to set voltage level and measure Z across the spectrum. I wonder how it will do. And of course a few commercial grid chokes for comparison will make for some entertaining comparisons.
cheers,
Douglas

Re: C-Core grid chokes [message #31585 is a reply to message #31584] Tue, 13 December 2005 11:33 Go to previous messageGo to next message
Damir is currently offline  Damir
Messages: 1005
Registered: May 2009
Illuminati (2nd Degree)
Hey, we need some columns, charts and photos in colour! And, finally, those Cw numbers... And mesurement of possible subsonic resonances with small-value coupling caps... And frequency response with cascode driver...etc.

measuring grid chokes [message #31586 is a reply to message #31585] Tue, 13 December 2005 16:05 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
That's what I had in mind. I will publish experimental set up, equipment used, and raw data. I have some access to a few commercial offerings( coincidently from winders who don't believe in publishing the data ). I am quite curious as to what they'll look like. I have heard stories, and look forward to either confirming them or disproving them...:)

The question is, should I attach a manufacturer's name to a set of test results?

Here is an open invitation to contribute to the experiments. Either with methods, or by providing samples. Best would be a choke with a published set of parameters, so the methods and experimental details can be compared.

I am more concerned with how my designs work and measure. The commercial, mass production, off-the-rack coils are going on the bench just for purposes of entertainment and comparison.
cheers,
Douglas

Re: measuring grid chokes [message #31587 is a reply to message #31586] Wed, 14 December 2005 08:52 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18786
Registered: January 2001
Illuminati (33rd Degree)

I think it would be wise to publish test results identifying the items being tested.

But there is one problem. You and I both have this same sort of dilemma.

Since you're pretty connected in the industry, your biases might be called into question. Better to avoid this sort of thing. The best way to do something like this is with independent confirmation. An objective outside party is not going to be questioned like you might be.

Then again, sometimes it's not economically possible to send samples out to a lab. In that case, I'd say publish your findings but be careful about interpreting them. If you post an unfavorable interpretation in a public forum, you'll probably be attacked. Or if you post proudly about your own work, even in a private forum, sometimes people will react. Not that controversy is always avoidable or even bad, but if you publish interpretations of work like this, it is bound to bring some your way.


Re: measuring grid chokes [message #31588 is a reply to message #31587] Wed, 14 December 2005 09:50 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
Hey Wayne,
You raise some interesting points. Thank you for the warnings.

I'd question the level of connection. I am just an interested DIY-er, just a customer. While I have had commercial ventures, they are in the past. Actually, one of the major points keeping me out of the commercial end are the restrictions it would put on my research.

As to bias, and attacks, I can deal with that. The attacks on the results can be discounted by the standard practice of publishing the details and equipment used to gather the results. For certain attacks, one must consider the source's bias and motivation too. For some, I suspect that all I'll have to do is mention the name in connection with a measurement and wait for the attack.

I made an open invitation to contribute suggested methods and samples. Since I have heard nothing on the method, let alone the sample offers, I'll assume a complete lack of interest in the project from any winders, and that this will continue while I post the measurements.

What will likely happen is that the criticism, and attacks will appear like cockroaches in the dark, and go away with similar speed when questioned in detail. When performing unbiased measurements, it is hard to become concerned about biased attacks, no matter how well they are coordinated. I have read both RAT and Kipling.
cheers,
Douglas

Re: measuring grid chokes [message #31589 is a reply to message #31588] Wed, 14 December 2005 13:07 Go to previous messageGo to next message
Manualblock is currently offline  Manualblock
Messages: 4973
Registered: May 2009
Illuminati (13th Degree)
I had a post to address this issue but after returning to post my thoughts I see you already have. Good Show; if you are straight with people and humble; you have no problems.
Why Wayne and Yourself would have to even considor what others think is crazy; you both have proven yourselves over and again; what else is there to say?
Any discussions you guys have just serve to benefit others. Thats why following out a thread is valuable; you never know what sits around the corner waiting to illuminate the subject.

Re: measuring grid chokes [message #31590 is a reply to message #31586] Wed, 14 December 2005 08:52 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18786
Registered: January 2001
Illuminati (33rd Degree)

I think it would be wise to publish test results identifying the items being tested.

But there is one problem. You and I both have this same sort of dilemma.

Since you're pretty connected in the industry, your biases might be called into question. Better to avoid this sort of thing. The best way to do something like this is with independent confirmation. An objective outside party is not going to be questioned like you might be.

Then again, sometimes it's not economically possible to send samples out to a lab. In that case, I'd say publish your findings but be careful about interpreting them. If you post an unfavorable interpretation in a public forum, you'll probably be attacked. Or if you post proudly about your own work, even in a private forum, sometimes people will react. Not that controversy is always avoidable or even bad, but if you publish interpretations of work like this, it is bound to bring some your way.


Re: measuring grid chokes [message #31591 is a reply to message #31586] Wed, 14 December 2005 08:52 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18786
Registered: January 2001
Illuminati (33rd Degree)

I think it would be wise to publish test results identifying the items being tested.

But there is one problem. You and I both have this same sort of dilemma.

Since you're pretty connected in the industry, your biases might be called into question. Better to avoid this sort of thing. The best way to do something like this is with independent confirmation. An objective outside party is not going to be questioned like you might be.

Then again, sometimes it's not economically possible to send samples out to a lab. In that case, I'd say publish your findings but be careful about interpreting them. If you post an unfavorable interpretation in a public forum, you'll probably be attacked. Or if you post proudly about your own work, even in a private forum, sometimes people will react. Not that controversy is always avoidable or even bad, but if you publish interpretations of work like this, it is bound to bring some your way.


Re: measuring grid chokes [message #31592 is a reply to message #31586] Wed, 14 December 2005 08:52 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18786
Registered: January 2001
Illuminati (33rd Degree)

I think it would be wise to publish test results identifying the items being tested.

But there is one problem. You and I both have this same sort of dilemma.

Since you're pretty connected in the industry, your biases might be called into question. Better to avoid this sort of thing. The best way to do something like this is with independent confirmation. An objective outside party is not going to be questioned like you might be.

Then again, sometimes it's not economically possible to send samples out to a lab. In that case, I'd say publish your findings but be careful about interpreting them. If you post an unfavorable interpretation in a public forum, you'll probably be attacked. Or if you post proudly about your own work, even in a private forum, sometimes people will react. Not that controversy is always avoidable or even bad, but if you publish interpretations of work like this, it is bound to bring some your way.


Re: measuring grid chokes [message #31593 is a reply to message #31589] Wed, 14 December 2005 14:24 Go to previous messageGo to previous message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
That is the whole idea. Fair and unbiased measurement. Why One would get so upset at the idea of their merchandise going under the 'scope is beyond me( and I never did say who/what gear I'd be measuring).

Especially in such a field as Audio. While the final judge is the ear, one gets valuable insight into design through measurement of some parameters which can be quantified, like inductance and winding capacitance.
cheers,
Douglas



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