Tips on Using Split Ferrite Beads

KWIDELITZ at delphi.com KWIDELITZ at delphi.com
Sat Nov 16 12:40:59 EST 1996


I  recently had the good fortune to spend some time with  George,
W2VJN.  George  helped  me with solving  some  insidious  TVI/RFI
problems both at home and at neighbors, due to both his knowledge
in  the use of ferrite and the liberal use of ferrite beads  from
the  large order I just got from Amidon of #77 split  beads.  (By
the  way, the beads wound up costing only $1.87 delivered  thanks
to  the size of the purchase I was able to make due to the  great
response  from the reflector.) I learned a lot that may show  how
naive I am to the engineers out there, but being an attorney/real
estate broker/investment adviser, these are things I did not know
and I'll bet some of you don't know either.

1. I always thought ferrite was like a sponge. You put it near  a
wire and it soaks up RF. I was surprised when George told me that
my  split ferrite beads that didn't quite make it fully around  a
cable would do no good. Ferrite beads that are split need to make
full contact at the split in order to work!

2. The recommended method of securing split beads (if they  don't
come in a plastic carrier) is with two tie wraps, one at each end
of the bead.

3.  I  was  also surprised to learn that  turns  through  a  bead
increase   the  effectiveness  on  a  geometric  basis,  not   an
arithmetic  basis.  That is, the effectiveness increases  as  the
square of the number of turns (3 turns is nine times as effective
as one turn or 9/4 times as effective as 2 turns, etc.)

4.  When trying to eliminate TVI/RFI the ferrite beads should  be
placed  close to the connector at  the amp/VCR/TV and not just at 
the speakers.

5. Bullet proof phones aren't necessarily bullet proof, but a few
turns of ferrite on the phone line leading to the phone can help the
situation, even on the phones  from Pro Distributors.

6.  Ferrite can be magic. With the exception on 10 meters,  where
the antenna is only 10 feet above one audio/video system, I'm now
completely clean on all bands, and only have a few minor problems
on  10. Same for the neighbors directly in the path to  the  east
coast and Europe. Clean as a whistle except for livable  problems
on 10. This is when running legal limit power.

My "lifetime" supply of ferrite probably won't last a  year,  let
alone  a lifetime. You can't have too much ferrite, be too  rich,
too thin or have too many antennas.

73. Ken, K6LA - Ken Six Los Angeles, KWIDELITZ at DELPHI.COM
                ex-AB6FO

>From N6NT at worldnet.att.net (Bruce Sawyer)  Sat Nov 16 17:45:39 1996
From: N6NT at worldnet.att.net (Bruce Sawyer) (Bruce Sawyer)
Date: Sat, 16 Nov 1996 17:45:39 +0000
Subject: Placing Tower Anchors in Sandy Soil
Message-ID: <19961116174536.AAA24711 at LOCALNAME>

I have been studying all of the Rohn recommendations for tower bases and
anchors, but every drawing they provide has a caveat which says,
essentially, that all bets are off if you don't have "normal" soil.  They do
provide a definition of "normal":  "'Normal' soil is a cohesive type soil
with a horizontal bearing capacity of 400 pounds per square foot per lineal
foot of depth.  Rock, non-cohesive soils, or saturated or submerged soils
are not to be considered as normal."  Nowhere, though, can I find a clue
what to do if your soil is not "normal".

My soil, as you can guess, is not normal.  It's sand.  To be more accurate,
it's a mixture of sand and ground up coral with a lot of coral rocks 4"-8"
mixed in with it.  More than that, I'll be putting one anchor only about 90'
from the water line, and during a major storm I have no doubt that this
point will become "submerged".  Looking at the Rohn diagrams, it looks like
a hunk of concrete 3'w x 4'l x 1'd, buried 3' in the ground, is all that
they recommend for anchoring my 80' of Rohn 45 in "normal" soil.  Clearly I
will need a lot more than that to put up my beachfront tower, but how much?
Does anybody here have experience, preferably successful experience, in
anchoring towers in sandy soil?

Bruce, N6NT/ZF8BS


>From tree at lady.axian.com (Larry Tyree)  Sat Nov 16 18:31:20 1996
From: tree at lady.axian.com (Larry Tyree) (Larry Tyree)
Date: Sat, 16 Nov 1996 10:31:20 -0800 (PST)
Subject: Master of reflector
Message-ID: <199611161831.KAA00406 at lady.axian.com>

K2GN writes:

> Now if the silent majority out there were to send a message
> to the master of this reflector, maybe he could put and end to
> all this nonsense and get it back to contesting.
>
> Larry, K2GN

The master of the reflector has gone away...  he is in HC8. 

The power to make the reflector what you want it to be is collectively
distributed to all of us.  

Perhaps when he gets back, Vanity call fever will have diminished to a
tolerable level after we have all gotten our hard copies, filed out our
refund forms and decided if N6FU is now the callsign we want to have.

73 Tree N6TR
tree at contesting.com
The ham previously known as WB6ZVC

>From aa0ob at skypoint.com (Greg Fields)  Sat Nov 16 18:27:08 1996
From: aa0ob at skypoint.com (Greg Fields) (Greg Fields)
Date: Sat, 16 Nov 1996 12:27:08 -0600 (CST)
Subject: SO 2 radio backlash?
Message-ID: <m0vOpSO-0003QZC at mirage.skypoint.com>

>
>My question to the group:  Is the resentment I have uncovered to these
>operating techiniques more widespread, or is my (small) sample statisically
>invalid? 
>
>73 - Gary

I too ran across the problem of answering a very loud CQ just to
have them call CQ again & again. One station in particular I called 4
times because I couldn't believe he didn't hear me. It then dawned on
me he was probably using two radios and working someone on the
second radio. This happened about a dozen times or more during
the SS CW test. This brings up another point. I understood you 
can't transmit on two frequencies at the same time. Are some
of these stations working the second rig and hitting F1 for the
first rig just to keep the frequency clear? I can't believe the
guy I called four times was only calling CQ while he copied the
exchange of the guy on the second rig. It seems to stay truly
competitive as a single op you now must run two rigs. Will that
mean we will answer more and more CQ's will no luck because of
the second rig? Is it time to have a single op, two rig category?
(That comment should start a interesting thread.)

73,

Greg K0OB




Greg Fields K0OB (Previously AA0OB)
aa0ob at skypoint.com
Minneapolis, Minnesota
U.S.A.



>From hwardsil at wolfenet.com (Ward Silver)  Sat Nov 16 19:04:07 1996
From: hwardsil at wolfenet.com (Ward Silver) (Ward Silver)
Date: Sat, 16 Nov 1996 11:04:07 -0800 (PST)
Subject: SO 2 radio backlash?
Message-ID: <Pine.OSF.3.95.961116110013.16337C-100000 at gonzo.wolfenet.com>


What works for me with respect to using two rigs, is to put one on a busy
band and tune the other for S&P on a less-busy band.  Or vice-versa.  Use
of dueling CQ's hasn't been that productive, although it has produced
little spurts of about 50% over what CQ-ing on one band would produce.
Using dueling CQ's on two busy bands generally causes more trouble than
it's worth.  It's a similar trade-off to chasing packet spots while trying
to run; few can make it work like it's supposed to and come out ahead.

I don't think it should be banned, but as we get a more sophisticated
understanding of the issues involved, we will probably see such tactics
used more appropriately.

73, Ward N0AX



>From w2vjn at rosenet.net (George Cutsogeorge)  Sun Nov 17 04:25:40 1996
From: w2vjn at rosenet.net (George Cutsogeorge) (George Cutsogeorge)
Date: Sun, 17 Nov 96 04:25:40 GMT
Subject: Ferrite Beads
References: <2.2.16.19961112053854.25071f80 at silcom.com>
Message-ID: <M.111696.202540.29 at ppp051.rosenet.net>

Here is some additional data on ferrite split beads taken on an HP Network 
analyzer.  The type 75 and 43 beads are manufactured split and have lapped 
surfaces.  The 43-S is 0.59 square by 1.125 long with a 0.25 hole.  The 43-L is 
1.02 square by 1.125 long with a 0.500 hole.  

The type 77 beads were cut with a diamond saw after manufacture.  The 77-S is 
about 0.56 OD by 1.1 long with about a 0.21 hole.  The 77-L is about 1.125 OD 
by 0.85 long with about a 0.49 hole.   



       Frequency       Type 75      Type 43-S   43-L    77-S    77-L

        0.15 MHz        -0.3 dB      -0.3       -0.35   -0.1    -0.3
        1.0             -2.4         -2.5       -1.7    -0.8    -2.6        
        3.0             -6.2         -7.1       -5.1    -4.5    -6.0        
        10.0            -11.0        -13.0      -10.7   -11.0   -5.3
        30.0            -16.0        -17.5      -15.4   -9.8    -4.8    
        50.0                         -18.7      -16.4   -8.1    -4.0

The 77 beads were used at K6LA and did a good job keeping RF out of various 
electronic appliances.  The 43 beads are a bit better (and more expensive) 
probably due to the lapped surfaces.  The sawn beads require more pressure on 
the joint to obtain the peak attenuation.  As Ken has stated, two tie wraps, 
pulled tightly, do a good job of clamping the beads together.
----
George Cutsogeorge,  W2VJN                   
Umpqua, OR.
http://www.qth.com/topten


>From tree at lady.axian.com (Larry Tyree)  Sat Nov 16 20:52:05 1996
From: tree at lady.axian.com (Larry Tyree) (Larry Tyree)
Date: Sat, 16 Nov 1996 12:52:05 -0800 (PST)
Subject: Two radios and answering CQs
Message-ID: <199611162052.MAA00933 at lady.axian.com>


K0OB responded to an original post by W9XT:

> >My question to the group:  Is the resentment I have uncovered to these
> >operating techiniques more widespread, or is my (small) sample statisically
> >invalid? 
> >
> >73 - Gary
>
> I too ran across the problem of answering a very loud CQ just to
> have them call CQ again & again. One station in particular I called 4
> times because I couldn't believe he didn't hear me. It then dawned on
> me he was probably using two radios and working someone on the
> second radio. This happened about a dozen times or more during
> the SS CW test. 

I am a little suprised this happened a dozen times, if so, you were
pretty unlucky (remind not to sit near you during a lightening storm).

Here is how this can happen, and how I probably did it several times
during the CW SS from W5WMU.  

First off, let me preface this by saying the computer can't send CW 
on two radios at once...  this is interlocked out.  If I provide a 
fill to the station I am working on the second radio, any transmission
on the first radio it aborted.

So, here I am, tuning around and I find a station calling CQ that
I haven't worked yet (say his call is K2PHF).  If we have both just
finished a CQ and I didn't get an answer, I will call him on the 
second radio.  The instant I am done calling him, I will start a CQ
back on my run frequency.  If he doesn't come back to me, I can just
let the CQ finish and answer anyone who comes back.  If he sends a 
? at me, I can press a single key and abort the CQ, resend my call, 
and then restart the CQ.  

Okay, now he finishes sending me my exchange, and it is time to send
him mine.  Perhaps someone called me and is waiting for me to come
back.  They will have to wait until I am done sending my exchange.
Most of the time, I can do this and the QSO takes place just fine -
so you see, that CQ isn't totally "fake".

However, what if the station I am working asks me for my check
three times...  Here I have a problem and it will take me longer
to come back to the other station.  

As I said, this might have happened three times the whole weekend.

I am not sure why you would hear 4 CQs - if this was because someone
was running two radios, they weren't doing a very good job of it 
at that time (please don't say I was one of them).

> can't transmit on two frequencies at the same time. Are some
> of these stations working the second rig and hitting F1 for the
> first rig just to keep the frequency clear? I can't believe the
> guy I called four times was only calling CQ while he copied the
> exchange of the guy on the second rig. It seems to stay truly
> competitive as a single op you now must run two rigs. Will that
> mean we will answer more and more CQ's will no luck because of
> the second rig? Is it time to have a single op, two rig category?
> (That comment should start a interesting thread.)

If someone is calling 4 CQs like that - they probably aren't 
competitive.  Two radios is a big challenge to do well.  It
takes a lot of practice and even then, it is complicated enough
that mistakes are made.

The concept of dualing CQs mentioned by Gary doesn't seem to be a 
weapon that works very well in a competitive effort.  I maybe used
it for one minute from W5WMU.  The concept is that as soon as one
CQ finishes on one band, you start one on the other band.  As soon
as you type a letter of a callsign responding to one CQ, the other
CQ stops and the computer is all set to let you complete the QSO
on the appropriate band.  The problem with it is that the CQs
must be very short - or you have too long of a dead spot on each
band.  Then they are too short to get much of a response. 

I use it for a few cycles when I have found a frequency on a second
band where I might be interested in running for awhile.  I will
call a few of these short CQs to find out if the frequency is really
is use or not (from the K3ZO operating manual).

Certainly two radios can cause some frustration - but I think it 
is a way for people who really want to win can put in hard work
and learn new tricks so they are more competitive.  It also means
if you get on on Sunday afternoon and call CQ, you will have a lot
of people answering you!!

Fight back - make the two radio guys call you!!

As far as resentment - there are two sources of this (in my opinion).
First off - there are those contest ops who aren't willing to make
the investment to learn this and would rather it went away.  To 
them I would say - too bad!  Then there are those who don't fully
understand how it works and think we are hogging two frequencies all
weekend.  I hope this post helps them understand the process
more clearly and invite them to use this forum to make their views
known.

73

Tree N6TR (op at W5WMU SS CW)
tree at contesting.com
The ham previously known as WB6ZVC

>From k5zd at ultranet.com (Randy Thompson)  Sat Nov 16 21:54:23 1996
From: k5zd at ultranet.com (Randy Thompson) (Randy Thompson)
Date: Sat, 16 Nov 1996 16:54:23 -0500
Subject: Dr. Pepper
Message-ID: <01BBD3DF.18672040 at k5zd.ultranet.com>

I can testify as to the value of Dr. Pepper.  It has been the contest =
drink of choice for all of my operating at N5AU and after.  That's 15 =
years of Dr. Peppers during contests, while programming, writing NCJ =
editorials, etc. =20

It works!

Randy, K5ZD


----------
From: 	K7BG Matt Trott[SMTP:aa7bg at 3rivers.net]
Sent: 	Friday, November 15, 1996 1:05 PM
To: 	cq-contest at tgv.com
Subject: 	Dr. Pepper

In the past I've never been an afficianado of Dr. Pepper as a contest =
swill,
but someone within the last year or so mentioned that it is the drink of
choice of K3ZO during tests. I've drained a 6 pack or so during the last =
few
SS's and it has been intrumental in score improvement. Just thought I'd
mention it if you need some extra help this weekend.

As an aside, not to take anything away from the champ, but I'm sure that
KRzeroY's Q total is due largely to his location in such a rare section. =
(I
only had 31 NTX's).

Good Luck,
Lou Zinnette




=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
Randy Thompson                                                           =
                     Amateur Radio Call Sign: K5ZD
E-mail: k5zd at ultranet.com
11 Hollis Street,  Uxbridge, MA 01569
h (508) 278-2355  w (508) 337-6600

>From ddjones at nas.com (Dale Jones)  Sat Nov 16 23:53:41 1996
From: ddjones at nas.com (Dale Jones) (Dale Jones)
Date: Sat, 16 Nov 1996 15:53:41 -0800 (PST)
Subject: Callsign Litigation (K8DD comments)
Message-ID: <m0vOuYP-000DFwC at cleese.nas.com>

        Hank, K8DD, commented on the "callsign litigation" issue,
        and in that comment--which I agree with--he had one slight
mis-statement.  That is: he stated "And now you don't have 
        to have your Extra for 25 years"      

        In the 1967 era (the first time that I am aware of when the 
        FCC allowed some amateur license holders to apply for 
        preferred calls on a mass basis) the FCC required applicants 
        to hold an Extra Class license at the time of application, 
        AND to prove that they held an amateur radio license of some 
        sort at least 25 years earlier.  That earlier call could have 
        been Class A, Class B, or whatever.  It is especially 
        noteworthy that the FCC did NOT require an applicant 
        to show that he held a call continuously during that 25
        year time period, or any other earlier time period.  The 
        applicant only had to possess a current Extra class license, 
        and show proof of having had some kind of ham license 25 years 
        earlier.  The FCC did not allow applicants to choose their
        new call sign, or submit a list of call signs.  The FCC issued
        the new calls quasi-randomly.  They began with the "W" prefix,
        and just issued 2-letter call signs begining at the alphabetical
        beginning to the next qualified applicant.

        During the 1976 era (The so-called Incentive Licensing era),
        the FCC required applicants to show that they held an Extra
Class license prior to certain dates, which would then 
        qualify the applicant for certain "gates" that the FCC 
        established. The first gate was set up for those "Old Timers" 
        who already had a 2-letter call or were otherwise qualified 
        to obtain one under the "Extra now + license 25 years ago" 
        scenario.  That first gate was established to enable the
        Old guys to have first shot at the GOOD call signs.  It 
        worked, because I recall that some OLD guy got my first
        choice in that Gate 1 granting of calls, which I was not
        qualified for.

        The second gate was for folks who held an extra class license
        prior to the FCC's official (written) discussion on incentive
        licensing.....that was some date in mid-1967 as I recall now.
        So once again, the applicants for gate 2 only had to show a 
        current Extra class license along with having held Extra at 
        the 1967 date.  More gates were established for applicants
        who held an extra class license which was issued on some later 
        dates.  No length-of-service was required, only that an Extra
        was held on the designated gate-date. And so on............

        So, just to clarify what is in fact a very insignificant 
        point, the FCC has never required holding an Extra class
        license for 25 years to qualify for preferred call signs.

        The issue of "litigation for a call sign" is absolutely
        and categorically ridiculous.  Who are the jack-asses 
        that are initiating the suits, anyway???  Can someone 
        smoke those suits out and list the litigants on this 
        reflector???? 
        
        73
        Dale K5MM 
        
        

At 04:31 PM 11/16/96 +0000, you wrote:
>
>At 08:11 11/14/96 -0500, you wrote:
>>-- [ From: Barry Martz * EMC.Ver #2.5.02 ] --
>>
>>Come on, litigation over a callsign?  Is it really that important?  This
>>gives amateur radio a real good name, fighting over a call.  
>>
>>
>
>If I remember right, the reason the FCC quit the 2-letter call program before
>about 1976 was from the letters to their congressmen and representatives after
>a bunch of us got 2-letter calls, after a heck of a longer wait than the Day 
>One calls.  Mine took several months.  And now you don't have to have your
>Extra for 25 years, or endure any of the Time-In-Grade cuts.  
>
>Besides, I'd probably go back to WN4KKN before most of the 2-letter calls!
>
>73    Hank    K8DD
>
>
>
>


>From jallen at vhfcom.com (John D. Allen)  Sat Nov 16 23:59:37 1996
From: jallen at vhfcom.com (John D. Allen) (John D. Allen)
Date: Sat, 16 Nov 1996 18:59:37 -0500
Subject: Dr. Pepper
Message-ID: <199611162356.SAA30154 at lucius.ultra.net>

The only 72 hour stint I ever powered was with Dr Pepper.

AMEN.


Go for it!!!

See you in CQWW CW

John K1AE

Powered by Dr Pepper.

> I can testify as to the value of Dr. Pepper.  It has been the contest drink of choice
 for all of my operating at N5AU and after.  That's 15 years of Dr. Peppers during
 contests, while programming, writing NCJ editorials, etc.  
> 
> It works!
> 
> Randy, K5ZD
> 
> 
> ----------
> From: 	K7BG Matt Trott[SMTP:aa7bg at 3rivers.net]
> Sent: 	Friday, November 15, 1996 1:05 PM
> To: 	cq-contest at tgv.com
> Subject: 	Dr. Pepper
> 
> In the past I've never been an afficianado of Dr. Pepper as a contest swill,
> but someone within the last year or so mentioned that it is the drink of
> choice of K3ZO during tests. I've drained a 6 pack or so during the last few
> SS's and it has been intrumental in score improvement. Just thought I'd
> mention it if you need some extra help this weekend.
> 
> As an aside, not to take anything away from the champ, but I'm sure that
> KRzeroY's Q total is due largely to his location in such a rare section. (I
> only had 31 NTX's).
> 
> Good Luck,
> Lou Zinnette
> 
> 
> 
> 
> ===============================================================================
> Randy Thompson                                                                                Amateur Radio Call Sign: K5ZD
> E-mail: k5zd at ultranet.com
> 11 Hollis Street,  Uxbridge, MA 01569
> h (508) 278-2355  w (508) 337-6600
> 
> 

John D. Allen, jallen at vhfcom.com



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