I have a schematic for a delta shaped loop that shows I'll need an 18:1
transformer to transform the 950 ohms of the antenna to 50 ohms (feeding it
with 50 ohm coax).
One transformer diagram shows an FT-140-43 core being used.
BUT, looking over some of Tom's, W8JI, write-ups, I see where he
: Topband: best core material?
Date: Mon, 5 Aug 2013 14:00:48 -0400
A full-wave delta loop would have the transformation done with a 1/4 wave
line of 75 ohm cable. This must be something other than a full-wave loop?
Bill VE3NH
- Original Message -
From: James Rodenkirch rodenkirch_
in smoke. I try
not to make a habit of it :-)
Tim N3QE
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of James
Rodenkirch
Sent: Monday, August 05, 2013 2:04 PM
To: BY THE LAKE; topband@contesting.com
Subject: Re: Topband: best core material?
Sorry
,
Charlie, K4OTV
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of James
Rodenkirch
Sent: Monday, August 05, 2013 2:04 PM
To: BY THE LAKE; topband@contesting.com
Subject: Re: Topband: best core material?
Sorry - didn't make it crystal clear
@contesting.com
Subject: RE: Topband: best core material?
Date: Mon, 5 Aug 2013 18:12:48 +
If receive only, you will do just fine using the 2873000202 binocular 73
material core that Tom mentions.
I think this corresponds to Amidon part number BN-202-73. Newark stocks the
part under
@contesting.com
Subject: Re: Topband: best core material?
Sorry - didn't make it crystal clear that this is a Delta shaped variant of
a EWE antenna
My bad for not utilizing all of the necessary verbiage to make that
clearyou see it in ON4UN's latest book on page 7-104.
From: ma...@isp.ca
[mailto:topband-boun...@contesting.com] On Behalf Of James
Rodenkirch
Sent: Monday, August 05, 2013 2:20 PM
To: Shoppa, Tim; BY THE LAKE; topband@contesting.com
Subject: Re: Topband: best core material?
I wasn't going to use a binocular core, Tim - I was going to use the Amidon
FT-140-43
else but still
fairly close to your mentioned 4:1 ratio)
From: charlie-cunning...@nc.rr.com
To: rodenkirch_...@msn.com; ma...@isp.ca; topband@contesting.com
Date: Mon, 5 Aug 2013 14:24:05 -0400
Subject: Re: Topband: best core material?
BTW, Jim
I assume that 18:1 is the impedance ratio
in a binocular core :)!)
Tim N3QE
From: James Rodenkirch [mailto:rodenkirch_...@msn.com]
Sent: Monday, August 05, 2013 2:20 PM
To: Shoppa, Tim; BY THE LAKE; topband@contesting.com
Subject: RE: Topband: best core material?
I wasn't going to use a binocular core, Tim - I was going to use the Amidon
FT-140
-
From: James Rodenkirch rodenkirch_...@msn.com
To: topband@contesting.com
Sent: Monday, August 05, 2013 1:33 PM
Subject: Topband: best core material?
I have a schematic for a delta shaped loop that shows I'll need an 18:1
transformer to transform the 950 ohms
: Topband: best core material?
Importance: High
I was going with the standard dimensions mentioned in the ON4UN book,
Charlie - 18' high, 28' wide at the baseBUT I really wanted to reduce
the height so your dimensions work far more better for me.
OK - I'm convinced on using binocular
: Re: Topband: best core material?
Thanks to all that replied - VERY informative information as well as
anecdotal evidence the small delta loop receive antenna works well AND at a
lower height, which I was thinking of doing but not sure if that mod would
alter the antenna's efficacy all that much
@contesting.com
Subject: Re: Topband: best core material?
I wasn't going to use a binocular core, Tim - I was going to use the Amidon
FT-140-43 OR the FT-140-77 IF it made any noticeable differenceis there
some magical reason to use binocular vice standard round?
From: tsho...@wmata.com
Yes, JC - ordering 73 material binocular cores today!
From: n...@comcast.net
To: rodenkirch_...@msn.com; tsho...@wmata.com; ma...@isp.ca;
topband@contesting.com
Date: Mon, 5 Aug 2013 15:49:37 -0400
Subject: Re: Topband: best core material?
If you plan to use the antenna on 160m you'll
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