Need advice on how to pick appropriate ferrite material for use in
baluns. In this case, a line isolator/choke to stop common mode current
on the feedline to a Carolina Windom.

Specifically, if EPCOS # B64290-L638-X35 cores would be a good choice for
such a project. What little information I have managed to find for this
part number does not help me much.

OD: .870"
ID: .539"
H : .25"
AL: 3200
ui: 5300

Looks like they would not be very snug on RG8, but could easily get a few
turns of RG58 through a stack of them.

--Teh

On Sat, 28 Apr 2007 10:49:40 +0000 (UTC), Tehrasha Darkon
wrote:

Need advice on how to pick appropriate ferrite material for use in
baluns. In this case, a line isolator/choke to stop common mode current
on the feedline to a Carolina Windom.

Specifically, if EPCOS # B64290-L638-X35 cores would be a good choice for
such a project. What little information I have managed to find for this
part number does not help me much.

OD: .870"
ID: .539"
H : .25"
AL: 3200
ui: 5300

Looks like they would not be very snug on RG8, but could easily get a few
turns of RG58 through a stack of them.

--Teh

I think you'll find some good informaton he

http://audiosystemsgroup.com/RFI-Ham.pdf

Danny, K6MHE

On Sat, 28 Apr 2007 06:04:41 -0700, Danny Richardson wrote:

I think you'll find some good informaton he

http://audiosystemsgroup.com/RFI-Ham.pdf

Danny, K6MHE

It is very good information, provided you are dealing with cores of a
known type. (#31 or #43) It would be nice if I had such material, and
in the end I may have to resort to purchasing some. *SHOCK*

But as it is, I am looking at some cores that appear to be #35 material,
and I cannot find any information as to how they react at freq. They
most likely are not 'ideal for my purpose, but I am trying to determine
if they can be used as 'close enough'. Either by adding more turns, or
stacking more cores. But again, without a data sheet, or having one in
hand to test manually this is rather difficult.

--Teh

Tehrasha Darkon wrote:
On Sat, 28 Apr 2007 06:04:41 -0700, Danny Richardson wrote:

I think you'll find some good informaton he

http://audiosystemsgroup.com/RFI-Ham.pdf

Danny, K6MHE

It is very good information, provided you are dealing with cores of a
known type. (#31 or #43) It would be nice if I had such material, and
in the end I may have to resort to purchasing some. *SHOCK*

But as it is, I am looking at some cores that appear to be #35 material,
and I cannot find any information as to how they react at freq. They
most likely are not 'ideal for my purpose, but I am trying to determine
if they can be used as 'close enough'. Either by adding more turns, or
stacking more cores. But again, without a data sheet, or having one in
hand to test manually this is rather difficult.

--Teh

What about characterizing what you have?

Here's a starting point:

http://k0bg.com/beads.html
Beads

Good luck.

Chuck

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Tehrasha Darkon wrote in news:f100t5$rsc$1
@news.netins.net:

....
It is very good information, provided you are dealing with cores of a
known type. (#31 or #43) It would be nice if I had such material, and
in the end I may have to resort to purchasing some. *SHOCK*

But as it is, I am looking at some cores that appear to be #35
material,
and I cannot find any information as to how they react at freq. They

Keep in mind that cores for chokes for suppression purposes need not and
are usually not of low loss material. Often the materials used for
suppression up to 500MHz might be quite lossy above 1MHz. Not only does
that loss not prevent them being effective, it is the main mechanisme
operating above typically 10 to 50 MHz. #43 is such a material.

I can't help you with characteristics of #35 material.

You might have to try to characterise it yourself, it isn't hard if you
have access to an MFJ259B or the like (or better). It is easy enough,
here is one I did for a part readily available in Australia:
http://www.vk1od.net/balun/index.htm . BTW, these cores cost about A
$35/metre whereas #43 cores of similar OD & ID cost about A$586/m (a
1600% price increas), or translated to a 300mm length for a balun, the
Jaycar LF1258 costs A$10.50 vs T-37-43 for A$175. (I know that the #43
cores are much cheaper in the US.)

Owen

Tehrasha Darkon wrote:
Need advice on how to pick appropriate ferrite material for use in
baluns. In this case, a line isolator/choke to stop common mode current
on the feedline to a Carolina Windom.

Specifically, if EPCOS # B64290-L638-X35 cores would be a good choice for
such a project. What little information I have managed to find for this
part number does not help me much.

OD: .870"
ID: .539"
H : .25"
AL: 3200
ui: 5300

Looks like they would not be very snug on RG8, but could easily get a few
turns of RG58 through a stack of them.

--Teh

Sorry, Teh. I misunderstood your
original post. Somehow I thought you
already had the beads.

If you're looking for a great "how-to"
on the subject, including choosing
proper beads, take a look at this:


http://www.yccc.org/Articles/W1HIS/C...S2006Apr06.pdf
CommonModeChokesW1HIS2006Apr06.pdf
(application/pdf Object)

Chuck

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----