>> I cut the RFI Ferrite blobs off of all trash Keyboards and stuff.
>> These are great Ferrite devices.
>> But what are they best for?
> Check out this article from Chuck Councilman W1HIS:
Wow, a long one, but on page 24 of 42 I learned a great technique. He
says, simply put a turn or two on any ferrite core and hook it to an
antenna analyzer. Then look at the impedance over frequency. At DC (or
your lowest frequency) the impedance should be very low (and 90 degrees)
Meaning the R is very low and the +jX is very high. Keep going up in
frequency to where the R and jX terms are equal. That is where the Q is
now 1 and the ferrite is starting to get quite lousy.
He also said that as you double frequency, the R part of the impedance
should also double. When you get to the frequencies where a doubling of
frequency no longer doubles R, then you are starting to get into
frequencies where this core is less effective.
That is exactly the kind of rule-of-thumb advice I was looking for! Now I
know what to do with all these cores!
Please note that ARTSAT1:INVADER (call:ZQ1ZKK, norad:39577U) has got its OSCAR number:
Cubesat OSCAR-77 (CO-77) was issued to INVADER on April 2, 2014.
We would like to express best thanks to AMSAT-NA and all of you.
ARTSAT Web Page: http://artsat.jp
ARTSAT Facebook Page: http://www.facebook.com/artsat
ARTSAT Project Leader
- Message from Mr. Bill Tynan, W3XO (2014/04/02)
Thank you for your reply.
>From what I can determine, the ARTSAT Project, INVADER satellite meets all of the qualifications necessary to receive an OSCAR number.
In accordance with your e-mail response, I will use Cubesat in the designation for this satellite. I therefore designate the ARTSAT Project INVADER satellite, Cubesat OSCAR-77 or CO-77. Thus CO-77 joins the earlier Japanese cubesats such as XI-IX(CO-57), XI-V(CO-58), Cute-I(CO-55), SEEDS-II(CO-66).
Congratulations to you and the entire ARTSAT team for the launch and operation of Amateur Radio satellite, CO-77. May its mission be a successful one.
William (Bill) Tynan, W3XO
AMSAT-NA OSCAR Number Administrator
TONIGHT - Wednesday night, Joe Walsh WB6ACU is going to be on the Ham Nation show with us.
Will be a blockbuster show with several in- studio guests. Joe will be introducing a new host
that is joining the show.
That is 6PM PDT / 8PM CDT, Wed April 2, 2014.
Go top http://www.twit.tv and click on WATCH LIVE! And join the discussion room!
PS Before ANYONE asks, "Why post this here, Clint???" - Well, if anyone has ever heard Joe perform,
they'd agree that his work is space-worthy and out of this world ... If that isn't good enough, just
know that Ham Nation has been very supportive of "working the satellites" - just view episodes 11
and 46, for starters ...
I cut the RFI Ferrite blobs off of all trash Keyboards and stuff. These
are great Ferrite devices.
But what are they best for? IE, 1) are they intentionally lossy or are
they High Q? and 2) What is their Optimium Frequency range (all ferrite
torroid coil forms come in a variety of materials optimized for different
frequency ranges. There is a big difference between the ferrite in a
switching power supply (100 kHz) and something usable at VHF or UHF.
I assume these ferrite tubes are probably optimized for digital and power
supply hash only and so probably only suitable for use at HF, but probably
not at VHF and UHF? And what is their Q? Can they be used for making high
Today I am using some on the outside of a coax right at the edge of a
cubesat to decouple the coax going to the network analyzer from the RF
enveolope of the spaceframe for antenna tuning. So today's question had to
do with their ability to serve as a high loss filter at UHF.
But we may as well list all we know about these ferrites for other
p.s. My method for getting them out of the molded rubber is to cut the
cable right clean at the ends. Then use a large drill (1/4") to drill out
all the internal wires. Then use a hacksaw to cut off one end of the
rubber as close as possible to the ferrite but without cutting it. Then
pealing back the rubber or nibbling at it with a pair of dikes.... Got a
hobby drawer full now.
Can't get any better than this. Life's Been Good.
----- Original Message -----
From: "Clint Bradford" <clintbrad4d(a)earthlink.net>
Sent: Wednesday, April 02, 2014 2:14 PM
Subject: [amsat-bb] Joe Walsh on Ham Nation Tonight!
> TONIGHT - Wednesday night, Joe Walsh WB6ACU is going to be on the Ham
> Nation show with us.
> Will be a blockbuster show with several in- studio guests. Joe will be
> introducing a new host
> that is joining the show.
> That is 6PM PDT / 8PM CDT, Wed April 2, 2014.
> Go top http://www.twit.tv and click on WATCH LIVE! And join the discussion
> PS Before ANYONE asks, "Why post this here, Clint???" - Well, if anyone
> has ever heard Joe perform,
> they'd agree that his work is space-worthy and out of this world ... If
> that isn't good enough, just
> know that Ham Nation has been very supportive of "working the
> satellites" - just view episodes 11
> and 46, for starters ...
> Sent via AMSAT-BB(a)amsat.org. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
The yearly 13 colonies event up to now also included a special separate
event for satellite operations.
This included a 13 colonies sweep satellite certificate. This is one of the
few awards still offered to satellite operators that has international
recognition. I can vividly remember the last time, 2 years ago giving
satellite operators the sweep from DE, most notably our Cuban friend Hector.
Last year we only had sat operations from 11 of the 13 states. I just did
an informal survey of the states that participated last year and find that
only 7 states will be active this year. The consensus among the 13 colonies
group is that this isn't going to work. We need to get all 13 colonies
involved. The states we need to get operations going from are.
CT DE MD NC PA RI
If we get the rest I will once again make the trip to DE to assure anyone
who wants the sweep. I know there has to be at least one good sat op in all
of these states, let's not let this die. Let me know off list if you're
interested in getting involved, I will do all I can to assist...
73 Jeff kb2m
The following paper "A Necro-Biological Explanation for the Fermi Paradox"
appeared on the physics preprint server this morning:
The Fermi Paradox asks, if there are other intelligent civilizations in the
galaxy, why have they not come to visit us?
I have no comment regarding the date of publication.