@contesting.com ;
Martinhamra...@vr-web.de
*Sent:* Thursday, December 15, 2011 11:43 PM
*Subject:* Re: Topband: T-200 vs. T-300
#2 powdered iron at mu of 10 is the lowest mu of the powdered iron types
listed with a frequency range that covers 160 meters (in some lists #2 is
2-30). You can
For those who intend to build the FCP INV. L. with a T-200-2 (or an
antenna tuner).
Me and a few guys from our club wound different types of baluns and
chokes on different material and measured them with a
analyser. We found the T-200-2 next to useless below 3 Mhz due to a low
AL value (uH/100
OK, but there is a huge amount of different materials in ferrites too.
Which kind of material did you use? I've used -61 material in a lot of
high power applications without any problems of them overheating. You
barely feel any temperature raise in them at all if for example using
them as a
A couple rules for toroidal inductors might be useful. To increase the
reactance you increase the number of turns -- the inductance goes up
approximately the square of the number of turns. To increase the power handling
capability you add additional cores to make a stack of cores. This will
Martin wrote:
BUT if you go QRO, you should stick with the iron powder cores.
I once replaced the T-200-2 in my homebrew s-match with a ferrite. I
changed back the same day, cuz after a few seconds with 750W the ferrite
got so hot you would not want to touch it. The T-200-2 runs cool over
to go off and buy parts and build.
The URL for his article is: www.audiosystemsgroup.com/RFI-Ham.pdf
Tod, K0TO
-Original Message-
From: ZR [mailto:z...@jeremy.mv.com]
Sent: Thursday, December 15, 2011 9:04 AM
To: Tod - ID; Martin
Cc: topband@contesting.com
Subject: Re: Topband: T-200 vs
For those building an isolation transformer for a 160M 5/16 FCP -- PLEASE
READ! IMPORTANT!
Martin has the right instincts, says it feels fishy for this. But it's
worse than he thinks. And don't even consider using ferrites.
The T300A-2 core and 20 bifilar turns were SPECIFICALLY chosen to
Guy Olinger K2AV wrote:
Martin has the right instincts, says it feels fishy for this. But it's
worse than he thinks. And don't even consider using ferrites.
The T300A-2 core and 20 bifilar turns were SPECIFICALLY chosen to produce
a
residual inductance value in the right order of
, December 15, 2011 2:39 PM
Subject: Re: Topband: T-200 vs. T-300
The Amidon T300A-2 can be replaced with a stacked PAIR of Amidon T300-2,
with a SINGLE Micrometals T300-2D, or a stacked PAIR of Micrometals
T300-2.
You can find the Micrometals cores on eBay. You CAN use the Amidon
T400A-2
Hi Rick,
No magic. Just the right stuff, for the FCP, anyway.
To your particulars, when Jerry Sevick measured various ferrites, he
measured the lowest loss at mu=40. This was very low, as was the #2
powdered iron at mu=10, the lowest of the powdered iron formulas. So use
of ferrites
:05 PM
Subject: Re: Topband: T-200 vs. T-300
Hi Rick,
No magic. Just the right stuff, for the FCP, anyway.
To your particulars, when Jerry Sevick measured various ferrites, he
measured the lowest loss at mu=40. This was very low, as was the #2
powdered iron at mu=10, the lowest
11 matches
Mail list logo
