Date: Fri, 8 Apr 2016 16:47:39 -0700
From: Jim Brown <jim@audiosystemsgroup.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] [Bulk] Re: BALUN revisited again
Message-ID: <5708431B.6030100@audiosystemsgroup.com>
Content-Type: text/plain; charset=windows-1252; format=flowed
On Fri,4/8/2016 11:36 AM, Bert Almemo wrote:
> As I was reading the post I was wondering if you could use ferrites of
> different mix in the same choke/balun? Would that work or not?
It could work for two chokes in series, as shown in the CMC-230-5K. But
since the ferrite materials are not specified for this product, it's
hard to say what they're using. It would make sense to use #31 for the
lower frequency choke and #43 for the higher frequency choke.
I think the power rating for this choke and the BL2006-3K may be overly
optimistic. I've fried a similarly constructed choke on a single #31
core with 1.5kW under heavy contest conditions with an 80M dipole.
Plugging the equivalent circuit into an NEC model shows the need for at
least twice the choking Z of a single choke. The second choke doesn't
need to be at the feedpoint -- it could be well down the line.
73, Jim K9YC
## say what ? AFIAIK, he uses FOUR type 31 cores for the CMC-230-5K ,
2 x cores for each assy. 8000-11,200 ohms of RS is nothing to sneeze at. Its
rated at 5 kw pep out. It wont blow up with 1.5 kw cxr. Its been tested.
2-30 mhz
## The BL2006-3k is a 14-54 mhz balun. Single core. 5400- 8600 ohms of RS
is again, nothing to sneeze at. Rated for 3 kw pep out. It wont blow up on
20-6m,
with 1.5 kw cxr.
## Your single core overheated on 80m. His BL2006-3k Is rated for 14-54
mhz.
Its not intended to be used on 80m!
Jim VE7RF
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