Polarisation Diversity Antenna (470-698 MHz)
The patented Diversity Fin™ is a multi-purpose antenna for wireless microphones that reduces dropouts using a cross-polarised, hybrid design.
It combines one LPDA (log-periodic dipole array) and one dipole antenna in an orthogonal (right angle) configuration. One element captures vertically polarised waves, and the other horizontally polarised waves - doing the same job as two "shark fin" paddles while greatly improving RF and audio performance.
To use, just connect both the A and B outputs on any antenna distributor or microphone receiver and point toward the stage (enure you use high quality 50Ω cable).
From high profile live sound events, to film and TV productions, to routine installations in schools and churches, Diversity Fin is the ideal all-purpose external antenna for diversity microphone systems of any brand.
Because DFIN (Diversity Fin) is such a unique solution, we've ripped the FAQ section from RF Venue's website, and pasted it below. There's a heap of extra information, well-worth perusing.
Diversity Fin FAQ:
(sourced via RF Venue website)
What is the range of the Diversity Fin?
The range of any wireless system depends on a number of factors, of which antenna type is only one. Antenna placement, noise floor, and interfering signals are by far the most significant factors in determining range. Very few live sound applications exceed antenna to mic distances of 300’. The Diversity Fin will provide the same or slightly better range than paddle/shark fin antennas, under the same RF conditions - which is more than enough for most production scenarios. Those who need longer range should consider the CP Beam.
How many DFINs are required per receiver?
Only one Diversity Fin is required per diversity receiver. The Diversity Fin is a polarisation diversity antenna system with two antenna outputs. Simply connect output one of the Diversity Fin’s outputs to channel "A", and the other to channel "B" on your wireless microphone receiver or antenna distributor. A single Diversity Fin can accommodate four or more receivers using a single or cascaded DISTRO4 antenna distributor.
Does the DFIN really work better than two paddles?
Yes. The Diversity Fin provides superior interference protection than a pair of matched paddle/shark fin antennas. The Diversity Fin eliminates multi-path interference and reduces switching noise using coincident placement of orthogonal elements. A technical description of the Diversity Fin's benefits is found in this white paper. (opens new window)
What about unity gain?
The Diversity Fin is a hybrid antenna with two elements: a dipole antenna with low gain, and an LPDA with medium-high gain. Experienced professionals have been told again and again that both antennas on a diversity receiver should be identical. We have discovered that unity antenna gain in a diversity system is a myth. We have debunked this myth again and again, quantitatively and in the real-world, since we released the Diversity Fin more than five years ago.
What is the frequency range? Are there other frequency ranges available?
The Diversity Fin is manufactured in two frequency ranges. A US version between 470-698 MHz, and an EU compatible version which is available on request. (edit: in Australia, Factory Sound recommends the US versions, 470-698 MHz, as listed on this page)
Does the Diversity Fin work with in-ear monitors?
The Diversity Fin was designed for receive applications in a diversity receiver system. Although it is technically possible to use one of the two antenna elements (LPDA or dipole) for a transmit application, like an in-ear monitor, none of the Diversity Fin’s benefits will carry over to a transmit scheme. In other words, it defeats the point. You're better off purchasing a single standalone paddle to use with your wireless monitor.
Is the Diversity Fin compatible with my Shure/Sennheiser/AKG/AudioTechnica/Lectrosonics/etc?
The Diversity Fin is compatible with any model of diversity receiver from any manufacturer that has detachable antennas/external antenna inputs and operates in the UHF broadcast range (470-698 MHz US, 470-790 MHz UK/EU). Diversity receivers have two antennas on the back.
How many Diversity Fins do I need for my wireless system?
Only one. Systems with more than one receiver should use a distribution amplifier like DISTRO4 to distribute multiple microphone signals through a single Diversity fin.
Does the Diversity Fin require DC power?
The Diversity Fin is a passive, unpowered antenna. It does not require power of any kind. All you need is coaxial (50Ω) cable. RF Venue discourages the use of so called "active" antennas. More on that here. (opens new window)
How many wireless microphones can I use with the DFIN?
You can use nearly unlimited wireless microphones with a single Diversity Fin if you use cascaded distribution amplifiers, like DISTRO4.
|Operating frequency:||470–698 MHz|
|Average return loss:||-9.4 dBm|
|Beam width:||140° azimuth|
|F/B ratio||-8 dBm|
|F/S ratio:||-5 dBm|
|Beam width:||100° azimuth|
|F/B ratio:||-5 dBm|
|F/S ratio:||-1 3 dBm|
|Operating temperature:||-23°C – 54°C|
|Connector(s):||(2) BNC female|