There are many types of receive antennas; however, in my estimation, nothing can beat a long Beverage.  For those who cannot install Beverages, one of the other types will surely be better than nothing at all.  Several of these other RX antennas have been written up in QST Magazine, Ham Radio and other publications and include, in no particular order, EWE, FLAG, PENNANT, K9AY LOOP, SNAKE, SHIELDED LOOP, LOW BEVERAGE, BOG ("BEVERAGE ON GROUND"), and "DO Loop" among others.
 

THE BEVERAGE
 

Because I have the room, the Beverage is my own RX antenna of choice.  I have 5 antennas between 1 and 1.5 wavelengths permanently installed in the pasture, and I add two more 1.5 wavelength antennas across neighbouring farm fields in winter.  All are at a height of 10 feet to permit cattle grazing underneath.  Each antenna is matched with a binocular core transformer (see below) and fed through 1/2" 75 ohm CATV hardline to a switchbox.  All antennas are kept grounded until a relay pulls the feed off ground.  The signal then runs via buried 1/2" hardline to a line selector switchbox in the basement beneath the shack.  Here, one of the coax lines from the antenna switch boxes is selected and the controller also selects which antenna from that relay box is to be connected.

There is a wealth of information available on the Beverage, and much of it is available via a number of web pages, some of which are shown on my TOPBAND LINKS web page.  What follows is more practical information for installing Beverage antennas.
 
 

LENGTHS

Much research has been done on the Beverage not only by its inventor, Harold Beverage but also by people such as Vic Misek, W1WCR.  While much of this work is quite technical , several pieces of practical data have emerged, the foremost  among these being the "sweet" lengths of wire for each band and optimum height above ground for varying soil types.  Knowing how long to make the antenna for a band of interest makes this receive antenna almost "plug and play".  Here are the optimum lengths as determined experimantally:

160M:   290ft        585 ft        880 ft        1160 ft

80M:     150 ft       295 ft        440 ft        580 ft

40M:     75 ft         150 ft        225 ft        295 ft
 

DIRECTIVITY and BEAMWIDTH,

The longer the antenna, the narrower the beamwidth.  For the space-restricted, the shortest length produces a beamwidth of almost 180 degrees while the longest has a 50 degree beamwidth.  The two lengths in between are 110 degrees and 80 degrees.  For 160M, an 880 ft length with an 80 degree beamwidth will permit covering all directions with just 5 antennas (though not optimally in all azimuths).
 

SUPPORTS

My choice of permanent support for the long Beverages is 12 ft cedar poles; with 24-36 inches buried in the ground there will be enough height to allow the cows, deer and the occasional tractor to pass under without problem.  For most of the antennas I use #17 "Galvalum" electric fence wire but for runs which are more than 100 feet between supports (across gullies and streams) I use #14 wire which is much stronger but more difficult to pull up taut.

With my first permanent antenna, I obtained some old hydro wall insulators and installed them on brackets at the top of each post.  The antenna was passed through the hole in the insulator and cinch wires were wound around the antenna wire after it was pulled up taut.  This is overkill and expensive if you don't have access to insulators.  So, for the remaining antennas I drilled the top of the post to take a short piece of small plastic or rubber hose, inserted the hose in the hole and then ran the wire through the hose.  Even this measure is probably not necessary, as wood is a good insulator.  The last pole in the line has an insulator attached to the top to enable me to snug up and secure the wire.

           Original construction technique using hydro                                             Current construction technique using
              insulator on a bracket                                                                                      plastic hose inserted in pole

Some people use electric fence insulators nailed to the side of the pole.  These carry the wire just fine until the first ice storm or until the weight of the taut wire deforms the plastic and the insulator breaks.  My construction technique has survived several ice storms over the years.
Some run the wire through branches of trees when the antenna passes through woods, and this does not seem to degrade the performance at all.
The bottom line: run the antenna on any kind of non-metallic support and it will probably work fine.

For the non-permanent Beverages, I use old steel fence posts about 4-5 feet long and pounded into the ground about 18".  Over these I slip a 10 ft length of grey plastic vacuum pipe (used for installing central vac systems and inexpensively obtainable at places like Home Depot).  The top of each pipe is notched in a "V" to a depth of 2 inches and the wire sits in this notch.  Using this system, I can install an 880 ft Beverage in about an hour by myself.  The pipe I am currently using shows no signs of degradation after several seasons' use.
 

MATCHING TRANSFORMERS

I have tried virtually every type of toroid and several different configurations and, until recently, had standardized on FT114-61 cores and a trifiliar or quadrifiliar winding.  The larger core is virtually lossless up to 10 mhz or so and the winding is relatively easy to place on the core.   Winding instructions for each type using the FT114-61 core are shown below, so pick your poison!  When winding any toroid, pay attention to the phasing or the transformer will not work properly, if at all.

MATCHING TRANSFORMER FT114-61 CORE, SEPARATE WINDINGS

If we assume that a single wire Beverage antenna installed over "average" ground will have an impedence of from 450-600 ohms, one can build a matching transformer with a 9:1 transformation ratio for matching to either 50 or 75 ohm coax cable.  As all my cables are CATV 75 ohm, I configure my Beverages so that the terminating resistance needed to produce a low and flat SWR across the design frequency is from 450- 600 ohms.  A height of 9-10 feet in my location seems to result in antennas which are in that range.  Different heights and types of earth will result in values which may be lower or higher than this.

Primary (antenna side) inductance: .573 uh
Al of FT114-61 core: 79.3
Turns needed for 9:1 transformation: 53 on primary (antenna) 18 on secondary (coax)
Just remember that the primary and secondary windings must be placed on opposite sides of the core.  You may have to use #28 to get all the turns on the core.  Remember, small wire does not stand up well to close encounters of the electrical discharge type!

NOTE: If you use an FT114-43 core, the turns required are 31 for the primary and 10 for the secondary, much easier to handle and you can use #24 wire.  The -43 mix core works up to 20M and above.

Note that there is no common ground for the coax     One of my plastic matching boxes.  This one                 This matching circuit with
shield and the primary winding ground.  Use of a       has an aluminum plate on the bottom so that                 switching relay for two antennas
plastic box for this application is mandatory.               I can have a common ground (circuit uses                     is enclosed in a Hammond diecast
                                                                                               a trifilar wound toroid).                                                     box.....excellent but expensive!

MATCHING TRANSFORMER FT114-61 CORE, AUTOTRANSFORMER STYLE, TRIFILIAR WINDING

PHASING OF TRIFILIAR WINDING ON CORE

For 75 ohm cable, a toal of 17.6 trifiliar turns are needed on the FT114-61 core.  Cut three equal lengths of #26 enamelled wire about 28" long and twist them together by placing in the jaws of a variable speed drill and turning slowly until there are about 4 twists per inch.  Wind the twisted cable onto the core, keeping the turns spaced evenly over the whole core.  It will be tight but you can squeeze the turns on.  Leave long pigtails at each end.  Secure the winding with adhesive at each end.  Then separate the wires in each pigtail end, strip off the varnish and "ring out" each end of each wire.  Use nail polish of various colours to identify each wire and then connect as shown in the diagram above.

MATCHING TRANSFORMER, BINOCULAR CORE, SEPARATED WINDINGS

I was persuaded to try the binocular core design, mainly because a number of high-profile lowband DXers have been using it with great success.  It is very easy to construct and has separate primary and secondary windings.  Here is a picture of one such transformer which I have placed in service on a Beverage antenna.  Primary consists of 2 turns #26 teflon covered, secondary consists of either 5 or 6 turns of #26 enamelled.  This particular core uses 6 turns secondary which gives slightly wider bandwidth and provides an excellent match to my 75 ohm cables.  The core itself is an Amidon BN-73-202.

                                                            Binocular BN-73-202 core.  The primary is to the right and
                                                                                       was wound first.

SOME OBSERVATIONS ON USING THE BINOCULAR CORE TRANSFORMERS

For several years I employed the FT114-61 core wound in autotransformer configuration with excellent results.  Not until I placed some binocular core transformers into operation did I realize that the separated windings of this design provide three advantages over the autotransformer design: (1) wider bandwidth between the 2:1 SWR points  (2) lower noise pickup  (3) much easier construction and repair after lightning damage.

Whereas the FT114-61 design provides good matching to a Beverage antenna up to about 9 mhz, the binocular design extends this to
over 20 mhz.  In most situations, this is meaningless.  However, for those wishing to employ a Beverage antenna above 10 mhz it means a significant improvement in SWR at the higher frequencies.  The binocular design maintains nearly 1:1 SWR from below 1.8 mhz to approximately 10 mhz, with reflected power rising slowly to about 1.8:1 at 20 mhz.   The FT-114 autotransformer on the other hand produces an SWR of over 3:1 above 10 mhz.  (These measurements of SWR were made using an MFJ-249 analyzer). For the purist this is significant -we need to squeeze every possible -dbm out of an antenna!  In actuality, we would most likely not be able to tell the difference between antenna operated at 1:1 and one operated at a mismatch of, say, 2:1.  Over 3:1, however, some degradation in antenna performance might be noticed.

It is in the area of overall noise reduction that the separated winding design shows its superiority.  The BN-73 core permits this form of
construction to be completed easily and quickly whereas using the standard toroid configuration it would not be possible to use the
FT114-61 core without overlapping the windings.  Of course, a different mix, say -43,  would enable the use of fewer turns, and the two
windings could be kept apart on the core.  I would expect very little difference in operation between a binocular core and a standard
toroid employed in a separated winding design.  Ease of construction, however, is another matter entirely.

When I placed the binocular core transformers in operation I immediately noticed a lowered noise level when using my Beverage antennas.  Separating the grounds on primary and secondary windings reduces the coupling of noise onto the coax shield and then to the receiver or preamp.   In one case the change was dramatic, in other cases more subtle.  One antenna which obviously points toward some noise source became noticeably more quiet.  The others which had been more quiet all along seemed to be even more so; however, how much of this is real and how much perceived is unclear!  Suffice it to say that I am very happy with the binocular transformers I have constructed.

             
                     Inside my RX controller.  A 20 db                               Built in a diecast aluminum box,
                     preamp stands vertically in front of                             this line selector handles all of
                    the power supply                                                            the cables from relay boxes at
                                                                                                            various places on the farm

                            
                                              SPDT 10 amp relays are standard in all my switch boxes.  The
                                              hardline runs terminate outside the house and RG-6 cable with
                                              F-connectors enters to the line selector.
Snake, Low Bev and BOG Antennas

EWE Antennas

Flag and Pennant Antennas

Other Low-Noise Receive Antennas