Hi Carl,
I and many others have been using Fair-rite 2873000202 binocular cores with
excellent success for years now.
http://www.newark.com/fair-rite/2873000202/ferrite-core-cylindrical/dp/02E8908
Using a VNA to measure loss through a pair of back-to-back connected 9:1
Beverage matching transformers shows much less than 1 dB loss through the pair
with low VSWR (I don't recall where I stored the detailed measurements I made
years ago). I'll repeat the loss and VSWR measurements through pair of
back-to-back 9:1 transformers, they're trivial to build.
http://www.w8ji.com/Beverages/BEVtrans.jpg
My BSEF receiving array is strictly monoband, the umbrella verticals are tuned
to resonance at 1840 kHz and the spacings are specific to 160 meters. Later
this year I plan to build two fully steerable 8-circle BSEF receiving arrays,
one for 160 and one for 80 meters.
http://www.w5zn.org/files/Design%20Construction%20&%20Evaluation%20of%20the%208%20Circle%20Vertical%20Array%20for%20Low%20Band%20Receiving%20Rev%203A%2002-25-2011.pdf
Unlike a passive BSEF receiving array, an array of short verticals with high
impedance amplifiers at the base of each vertical provides the basis for an
excellent multi-band receiving array. I don't plan to take that route, I have
adequate space for monoband BSEF receiving arrays.
http://www.hizantennas.com/4_8_pro_8_element_array.htm
http://www.dxengineering.com/search/department/antennas/section/receive-antennas-and-arrays/part-type/hf-receive-vertical-antenna-array-packages/receive-array-type/eight-circle/product-line/dx-engineering-receive-eight-circle-array-electronics-packages?autoview=SKU
High gain amplifiers at the feedpoints of the verticals can pose a problem in
the harsh RF environment of a multi-operator multi-transmitter contest station,
particularly in my case where we have excellent capabilities to simultaneously
receive within a few kHz of the transmitter.
73
Frank
W3LPL
---- Original message ----
>Date: Sun, 3 Feb 2013 09:22:54 -0500
>From: "ZR" <zr@jeremy.mv.com>
>Subject: Re: Topband: Subject:RE: New 160M high performance receiving antenna
>at W3LPL
>To: <donovanf@starpower.net>
>
>http://www.newark.com/fair-rite/2873000202/ferrite-core-cylindrical/dp/02E8908
>
>
>73 Mix Frank? I thought 31 was the latest choice but for monoband it doesnt
>matter.
>
>Any plans on doing a 160-40M design?
>
>Carl
>
>
>----- Original Message -----
>From: <donovanf@starpower.net>
>To: <topband@contesting.com>
>Cc: "Ron Spencer" <ron.e.spencer@gmail.com>
>Sent: Saturday, February 02, 2013 3:38 PM
>Subject: Topband: Subject:RE: New 160M high performance receiving antenna at
>W3LPL
>
>
>> Hi Ron,
>>
>> Construction of a phase inversion transformer is covered in detail on page
>> 23 of the excellent paper published by W5ZN and N4HY:
>>
>> http://www.w5zn.org/files/Design%20Construction%20&%20Evaluation%20of%20the%208%20Circle%20Vertical%20Array%20for%20Low%20Band%20Receiving%20Rev%203A%2002-25-2011.pdf
>>
>> My phase inversion transformer uses the Fairite 2873000202 binocular core
>> popularized by W8JI for use in Beverage matching and receiving crossfire
>> transformers.
>>
>> http://www.newark.com/fair-rite/2873000202/ferrite-core-cylindrical/dp/02E8908
>>
>> My transformer windings are made of twisted red and white 26 AWG insulated
>> telephone wire or you could use Category 5 Ethernet cable or just about
>> any other small diameter insulated wire. The twisted pair is passed three
>> times through both holes in the binocular core (three times returning back
>> to the starting point of winding). The red wire is grounded at one end of
>> the twisted pair and the black wire is grounded at the opposite end of the
>> twisted pair. The remaining wires are the input and output of the phase
>> inversion transformer. It took me longer to type this explanation than
>> to fabricate a transformer!
>>
>> I'll be happy to answer any further questions.
>>
>> 73
>> Frank
>> W3LPL
>>
>>
>>
>>
>> ---- Original message ----
>>>Date: Sat, 02 Feb 2013 12:02:24 -0800
>>>From: Ron Spencer <ron.e.spencer@gmail.com>
>>>Subject: BSEF array
>>>To: donovanf@starpower.net
>>>
>>>Frank sounds intriguing. Can you supply details of the phase inverting
>>>transformer?
>>>
>>>Thanks
>>>
>>>Ron
>>>N4XD
>> _________________
>> Topband Reflector
>>
>>
>> -----
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>>
>
_________________
Topband Reflector
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