RF Diversity Fin antenna...anyone familiar with this?

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Bill Kexel

Well-Known DJ
Dec 5, 2006
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Phoenix, AZ
Anyone here have any experience with this antenna? I'm looking to improve my signal coverage during outdoor ceremonies/decrease signal fades, audio dropouts, etc.

Occasionally I have had large ceremonies where the only setup location available is behind all the guests. And it seems the signal isn't as strong when it is going thru 150+ guests with smart phones, tablets, I-pads, etc.

I am noticing more wireless mic problems than in the past. When no guests are there, it's crystal clear. Once the ceremony starts, and guests are all standing with their electronics, it's a different story. Maybe I need an antenna on a tall pole?...LOL

I am using (2) EV RE2 lav mics with the dual 1/2" antennas, and that is proving to be no enough. I have read great things about this "Fin" and wondered if anyone was using it?
Diversity Fin Antenna
 

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No experience with this particular unit, but paddles, used properly, do provide a stronger signal .. HOWEVER .. they are MUCH more directional than standard whip antennas. If the transmitter is relatively stationary (a ceremony probably is), where you can aim the antenna at it, you will typically get a much stronger signal. For a reception, where people walk around (toasts), you may find it frustrating.

Another option is to leave the receiver close to the transmitters and run a long (100') cable back to the mixer. We use to do that in noisy RF areas for bands (usually through the snake).
 
Thanks Steve. I know these "Fin" antennas are popular in mega churches, concerts, festivals, etc. For me, this would be for ceremonies. My DJ case has 4 wireless mics all rack mounted in there. It would be nice to use a distro 4 & have all the mics connected to this same antenna. Sometimes, the DJ has to set up way in the back behind all the guests & all those bodies & their electronic devices become a big wall/barrier for the simple antennas that are mounted on the receivers.
 
If your units don't have them, sometimes adding a 1/2 wave antenna helps: Electro-Voice FA-XX Flexible ½ Wave UHF Antenna

I bought an EV APD4+ antenna distribution hub a few years back and it works great. I actually use it for my Audio-Technica mics, but they sit in the same bandwidth so it wasn't an issue. If you watch eBay carefully, sometimes they come up .. got this one for less than $200. Had to find antenna jumper cables though (found them on eBay) and power jumpers (made them). Haven't tried paddles .. the 1/2 wave antennae work pretty good.
 
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A vertical antenna, which is what you are using now, is an antenna that "radiates equally poorly in all directions". Anything that directs more of the energy in a specific direction will help (like that fin antenna), to the detriment of areas the antenna is not aimed at.
 
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I'm curious if dual, dual diversity antennae interfere with each other. Maybe a simple antenna splitter ( Shure UA221 Passive Antenna Splitter/Combiner Kit - Antenna splitter kit ) with a single pair on top might work better?

One nice thing about the new Audio Technica System 10 Pro is the receiver/antenna pack can be remotely mounted from the case and connected back with cat5 cable .. allows you to stick them way up in the air if necessary.

system_10_pro_gp_1_sq.jpg
 
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It is possible that they are interfering with each other, but the first thing I would do before I invest in a distribution unit is remove the receivers from your main rack.

Put them in their own separate rack which will not only give you better portability for placement options, there may just be some stray RF interference coming from one of the components in your main rack that may be causing dropouts.

Either way, it's better to keep the antennas isolated from other nearby electronic sources as much as possible.
 
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I have been using this system for about the past 6 years, always worked perfectly. Same goes for when I set up & test everything before guests arrive. I do a channel scan, test them for sound quality (feedback, bounceback, wind, etc.) I also set each unit up where they (minister & groom) will be standing and then go back & adjust the antennas etc. It always tests clean & sharp.

The problem I have is AFTER the guests arrive & the bride is coming down the isle. I think the combination of 100+ guests standing, (then hopefully sitting) between me & the transmitters, plus all the electronics (Ipads, smart phones, etc.) are causing signal problems for my wireless mics.
For smaller ceremonies, it seems to be fine, but if it is a large group & I am put way in the back, it's a challenge.

I think that I either need to be closer (if possible) or get a stronger antenna, ....or get it up higher?
 
Higher will usually be better, closer will usually be better. Have you made any changes in how things are positioned?

2_Corner_Reflector_Antenna.jpg


This is a corner reflector for a UHF antenna. You see them outside all the time, usually with a wire grid reflector simply to reduce wind load. A flat metal plate also works. The physics behind this (pun intended) is exactly the same as corner or wall loading a sub, and applies equally to receiving and transmitting. My point is you may have (in the past) been positioning the antennas, simply by shear accident, in front of some metal that may have been doing this.
 
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Body pack transmitters suck compared to handhelds due to their placement. I agree with what's already been said in that I would (and do) run a long XLR closer to the action to avoid problems.

I use AT 3000 series wireless systems and the lav & handheld transmitters allow me to switch them from LOW to HIGH output for just this reason. The HIGH setting is harder on the batteries but it works pretty well. Check the manual to see if your mic system offers this feature.

I have also mounted my received onto a lighting tree shelf at times so it's nice and high. Once you get that direct line of sight, you are pretty much set. Unless of course the minister has a sweaty back. LOL!
 
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Ironically, the minister
Body pack transmitters suck compared to handhelds due to their placement. I agree with what's already been said in that I would (and do) run a long XLR closer to the action to avoid problems.

I use AT 3000 series wireless systems and the lav & handheld transmitters allow me to switch them from LOW to HIGH output for just this reason. The HIGH setting is harder on the batteries but it works pretty well. Check the manual to see if your mic system offers this feature.

I have also mounted my received onto a lighting tree shelf at times so it's nice and high. Once you get that direct line of sight, you are pretty much set. Unless of course the minister has a sweaty back. LOL!

Ironically, this minister was sweating big time. It was a hot day & this guy was a big heavy dude that was wiping his face/bald head about every 30 seconds with a towel. Maybe that's what caused it! LOL!
 
or as TJ suggested, put the receivers in their own small case and now you have the flexibility of placing that case in a different (higher or further) position.

You have some flexibility if you use the 1/2 wave antennae .. they don't need a groundplane (the 1/4 wave ones do), so you could just take those whips and mount them up higher without a paddle.

A couple of good reads:

Avoid These Five Mistakes in Wireless | Shure Blog
Wireless Systems and Antenna Placement | Shure Blog
or as TJ suggested, put the receivers in their own small case and now you have the flexibility of placing that case in a different (higher or further) position.

You have some flexibility if you use the 1/2 wave antennae .. they don't need a groundplane (the 1/4 wave ones do), so you could just take those whips and mount them up higher without a paddle.

A couple of good reads:

Avoid These Five Mistakes in Wireless | Shure Blog
Wireless Systems and Antenna Placement | Shure Blog
Line-of-Sight.jpg
This image says alot. How many DJs set up a ceremony similar to the lower image. When guests are standing at the beginning/end...look out!
 
The best advice is to place your mic receivers as close to the action as possible. At stage events for example, the wireless position is consistent with the monitor position - right at the side of the stage. The resulting audio is then routed back to the FOH. Helical (diectional) antennas are used for in ear monitors so the field of reception remains focused on the point of interest.

Use paddle and helical antennas when you have no choice but to put the antennas far away (more than 20 feet for the class of mic you are using.) These will increase the range of the system, and are directional. They are often specific to a given frequency band so be certain whatever you use is compatible with your mics. It's important to know what other signals might be present and interfering because if those sources are also in the applied direction you'll still have issues regardless of the directional antenna. (Check to know what other vendors are using at the same event.)

A crowd of people will absorb a lot of RF energy, or at least kill many of the reflections that help the waves to find your antennas. Your antennas (no matter what the type) need to be high enough to have a line of sight to the transmitter. THIS IS AN ABSOLUTE CONDITION WITH UHF FREQUENCIES. (Coincidentally, this was U.S. Government's primary basis for moving Digital TV to the UHF band. (The majority of antenna user's would be forced onto cable systems resulting in a windfall of new Federal and State tax revenue - no more FREE TV.} UHF antennas REQUIRE a clear line of sight to the transmitter. (That whole "get a free digital antenna" from the Government deal was a fraud. They could only ever work if you can actually SEE the radio tower form your house. Nice if the world was flat, worthless otherwise.)

If you started with VHF wireless systems you may have developed a set of habits that is detrimental to UHF systems. VHF frequency characteristics are far superior. UHF requires a different approach.