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" <[email protected]> >Subject: Re: Topband: Subject:RE: New 160M high performance receiving antenna >at W3LPL >To: <[email protected]> > >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: <[email protected]> >To: <[email protected]> >Cc: "Ron Spencer" <[email protected]> >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 <[email protected]> >>>Subject: BSEF array >>>To: [email protected] >>> >>>Frank sounds intriguing. Can you supply details of the phase inverting >>>transformer? >>> >>>Thanks >>> >>>Ron >>>N4XD >> _________________ >> Topband Reflector >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 10.0.1430 / Virus Database: 2639/5576 - Release Date: 02/02/13 >> > _________________ Topband Reflector
