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Author Topic: Do I need a antenna?  (Read 407 times)

Jose Quiray

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Do I need a antenna?
« on: September 19, 2022, 09:48:35 AM »

OK, I do some announcing for a local bike race series. And I use a wireless microphone system shure BLX4R H10 and I would like to extend my range away from from the stage. Iím not sure what type of antenna or other type of set up that I would need to do this.
And now that being said the race series will not be paying for this I will be and this is not my full-time job so any suggestions will definitely help as I am doing this just to help them out.

Thank You very much for all your help.
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Paul Johnson

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Re: Do I need a antenna?
« Reply #1 on: September 19, 2022, 12:25:08 PM »

How far do you want to go from the receiver? The simple antennas are omni directional and range is pretty short reliably. Add paddle antennas and aim them will perhaps double the range. Frankly, 100yds is pushing it, 100ft possible and for dropout and interference free results, think more like 50ft!

You can do things to improve things. Low loss feeder to better antennas up high can be worthwhile, and even narrower beams - 5 element yagis, for example, might be even better - but as you go further, the beam width is less so if you suddenly move the wrong way , you walk out of the beam. How much money have you got?

It is possible to an an extra receiver further away and run long cables from there back to the mixer. All these things cost money.
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Jose Quiray

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Re: Do I need a antenna?
« Reply #2 on: September 19, 2022, 12:43:40 PM »

Paul, Thank you! :)
Money is tight as I will be paying for everything as it is for a nonprofit and I am volunteering my time and equipment. 

Max distance is maybe 100 ft so any suggestion would be great!




How far do you want to go from the receiver? The simple antennas are omni directional and range is pretty short reliably. Add paddle antennas and aim them will perhaps double the range. Frankly, 100yds is pushing it, 100ft possible and for dropout and interference free results, think more like 50ft!

You can do things to improve things. Low loss feeder to better antennas up high can be worthwhile, and even narrower beams - 5 element yagis, for example, might be even better - but as you go further, the beam width is less so if you suddenly move the wrong way , you walk out of the beam. How much money have you got?

It is possible to an an extra receiver further away and run long cables from there back to the mixer. All these things cost money.
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Don Boomer

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Re: Do I need a antenna?
« Reply #3 on: September 19, 2022, 12:53:29 PM »

Antennas themselves donít have a range limit.  They pick up forever Ö but Ö they have a usable range that is dependent mostly on the amount of local interference at your venue.  So your usable range will likely be much greater on top of a mountain in Idaho than in the middle of Times Square.

Using only a single channel with a distance of only 100í you stand a reasonable chance of using the stock whip antenna provided you can ensure you maintain line of sight to your transmitter.  Typically that means youíll need to get your antenna above the head height of your audience and you donít have trees or other obstacles in the way. 
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Jose Quiray

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Re: Do I need a antenna?
« Reply #4 on: September 19, 2022, 01:14:21 PM »

THANK YOU, DON!!


Antennas themselves donít have a range limit.  They pick up forever Ö but Ö they have a usable range that is dependent mostly on the amount of local interference at your venue.  So your usable range will likely be much greater on top of a mountain in Idaho than in the middle of Times Square.

Using only a single channel with a distance of only 100í you stand a reasonable chance of using the stock whip antenna provided you can ensure you maintain line of sight to your transmitter.  Typically that means youíll need to get your antenna above the head height of your audience and you donít have trees or other obstacles in the way.
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Dave Garoutte

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Re: Do I need a antenna?
« Reply #5 on: September 19, 2022, 03:02:43 PM »

If you have time, go ahead and experiment!  Set up your rig and start walking.
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Paul Johnson

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Re: Do I need a antenna?
« Reply #6 on: September 19, 2022, 04:10:56 PM »

One trick I learned with UK broadcasters was that you could use antenna combiners and run quite long cables so you could put antennas gradually getting further away. We even put the receiver hidden in some bushes with a car battery for one shot. The presenter started a really long way away from the camera, and was slowly walking down the country lane with the long lens slowly pulling out. Going out live, so no chance of a recorder in the pocket. I'd estimate the furthest point was around 300m or so - a long way. The extra receiver went out to be central to the second half, and we ran satellite cable which wasn't too lossy at radio mic frequencies further out and further back to dipoles strategically placed in the hedgerow. The power splitters were small passive devices - no preamps. these went to one receiver input, so it had 3 (or 4 can't remember) cables going to the antennas. The other socket just had the usual vertical, as a fallback. This was repeated at the close receiver. We managed to get dropout free audio as the moving presenter would go down on one antenna and up on the next, and repeat. The mixer just had the distant fader up, and started to crossfade to the near receiver as they got closer. Worked pretty well.
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Brian Jojade

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Re: Do I need a antenna?
« Reply #7 on: September 19, 2022, 09:43:34 PM »

One trick I learned with UK broadcasters was that you could use antenna combiners and run quite long cables so you could put antennas gradually getting further away. We even put the receiver hidden in some bushes with a car battery for one shot. The presenter started a really long way away from the camera, and was slowly walking down the country lane with the long lens slowly pulling out. Going out live, so no chance of a recorder in the pocket. I'd estimate the furthest point was around 300m or so - a long way. The extra receiver went out to be central to the second half, and we ran satellite cable which wasn't too lossy at radio mic frequencies further out and further back to dipoles strategically placed in the hedgerow. The power splitters were small passive devices - no preamps. these went to one receiver input, so it had 3 (or 4 can't remember) cables going to the antennas. The other socket just had the usual vertical, as a fallback. This was repeated at the close receiver. We managed to get dropout free audio as the moving presenter would go down on one antenna and up on the next, and repeat. The mixer just had the distant fader up, and started to crossfade to the near receiver as they got closer. Worked pretty well.

This opens up a whole different can of worms regarding to interference, reflections, etc.  While it might work in some scenarios, it's a massive mess in others.

The little 1/4 wave antennas on the BLX units are typically fine for use in say a small conference room or on a stage.  Think 30-40 feet as a a maximum reliable range.  Yeah, it'll usually work further than that, but you'll experience occasional dropouts.

You can move the antennas off of the receiver, but remember that the 1/4 wave antennas require a grounding plate to be useful. All 1/4 wave antennas work best if they are installed in the center of a metal ground plane with at least 1/4 wave length radius (1/2 wave length diameter: ~8 inches for 550Mhz larger is better. The antenna can still work on a smaller ground plane but the efficiency will be reduced.   Clearly then, being attached just to the back of the receiver means a pretty small ground plane.

Upgrading to a 1/2 wave antenna eliminates the need for this ground plate.  Attaching a 1/2 wave antenna directly to the receiver will offer a noticeable improvement in signal.  It's slightly better than moving the 1/4 wave antenna to a proper ground plate but only by less than a quarter dB or so.  When picking the antenna, make sure to get one tuned to the appropriate frequency.  Using the wrong length will make things worse.

https://www.sweetwater.com/store/detail/UA8-518-578--shure-ua8-518-578-1-2-wave-omnidirectional-antenna

These are relatively inexpensive and in my experience effectively doubles the usable range of the mics.  That would put you at a reliable working distance of 60-80 feet.  Might be good enough for your 100' outdoor requirement if you've got line of sight to where you need it.  You can also easily add some low loss cable to get the antenna closer to where you need it to be and keep the receiver in your rack.

The next step is to move up to paddle antennas.  Shure offers 2 different units, a passve unit for $300 and an active for $404.  The active unit includes a built in amplifier to compensate for cable losses. This is only required if you're running long RF cable runs. If you are using less than 50 feet of cable, the active unit will give you no advantage. (amplifying only really helps for cable loss, not an increase in true usable gain).

The antennas are sold each, but are used best in pairs.  The Shure Paddles are directional, so you can point them in the direction you are using the mic. With 2 paddles, you can give yourself a wider coverage area.  My experience is in the direction the antennas are pointed, you can get a 300-500' range.  That range drops off quickly as you get off axis of the paddle.  At 90 degrees from the paddle, range is around 100 feet or so.

You could use just a single antenna if your budget is super tight.  The diversity system uses 2 signals and picks the better of the 2.  With 1 paddle you essentially would be giving up diversity. Same thing happens if you point the antennas in different directions.

Alternatively, the neat thing is antennas are antennas.  As long as their frequencies match, you're not forced to use the name brand that matches your mics.  I personally use the Audio Technica ATW-A49 paddles.  They were less than half the price of the Shure alternative when I got them and work great.  Pretty rugged too.  Got ripped through the air 50 feet while attached to a mic stand during a storm once, and survived!

There are even cheaper alternatives if you look into the knockoff stuff online.  I'd be a little leery about any of the stuff with amplifiers or distribution, but for the basic antenna part, there's not a lot of risk going with the cheapies.

If you're REALLY tight on a budget, you can even build your own if you so desire. It's not complicated. You just need to build a circuit board with traces the right lengths and add a connector.  Probably could build one for under $20.

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Brian Jojade

Jose Quiray

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Re: Do I need a antenna?
« Reply #8 on: September 21, 2022, 02:17:05 AM »


Brian ,
All I can do is announce and I know Iím good at it. But Brian my friend you just crushed the best explanation that I needed to get this info crystal clear.

Thank you seriously, 


This opens up a whole different can of worms regarding to interference, reflections, etc.  While it might work in some scenarios, it's a massive mess in others.

The little 1/4 wave antennas on the BLX units are typically fine for use in say a small conference room or on a stage.  Think 30-40 feet as a a maximum reliable range.  Yeah, it'll usually work further than that, but you'll experience occasional dropouts.

You can move the antennas off of the receiver, but remember that the 1/4 wave antennas require a grounding plate to be useful. All 1/4 wave antennas work best if they are installed in the center of a metal ground plane with at least 1/4 wave length radius (1/2 wave length diameter: ~8 inches for 550Mhz larger is better. The antenna can still work on a smaller ground plane but the efficiency will be reduced.   Clearly then, being attached just to the back of the receiver means a pretty small ground plane.

Upgrading to a 1/2 wave antenna eliminates the need for this ground plate.  Attaching a 1/2 wave antenna directly to the receiver will offer a noticeable improvement in signal.  It's slightly better than moving the 1/4 wave antenna to a proper ground plate but only by less than a quarter dB or so.  When picking the antenna, make sure to get one tuned to the appropriate frequency.  Using the wrong length will make things worse.

https://www.sweetwater.com/store/detail/UA8-518-578--shure-ua8-518-578-1-2-wave-omnidirectional-antenna

These are relatively inexpensive and in my experience effectively doubles the usable range of the mics.  That would put you at a reliable working distance of 60-80 feet.  Might be good enough for your 100' outdoor requirement if you've got line of sight to where you need it.  You can also easily add some low loss cable to get the antenna closer to where you need it to be and keep the receiver in your rack.

The next step is to move up to paddle antennas.  Shure offers 2 different units, a passve unit for $300 and an active for $404.  The active unit includes a built in amplifier to compensate for cable losses. This is only required if you're running long RF cable runs. If you are using less than 50 feet of cable, the active unit will give you no advantage. (amplifying only really helps for cable loss, not an increase in true usable gain).

The antennas are sold each, but are used best in pairs.  The Shure Paddles are directional, so you can point them in the direction you are using the mic. With 2 paddles, you can give yourself a wider coverage area.  My experience is in the direction the antennas are pointed, you can get a 300-500' range.  That range drops off quickly as you get off axis of the paddle.  At 90 degrees from the paddle, range is around 100 feet or so.

You could use just a single antenna if your budget is super tight.  The diversity system uses 2 signals and picks the better of the 2.  With 1 paddle you essentially would be giving up diversity. Same thing happens if you point the antennas in different directions.

Alternatively, the neat thing is antennas are antennas.  As long as their frequencies match, you're not forced to use the name brand that matches your mics.  I personally use the Audio Technica ATW-A49 paddles.  They were less than half the price of the Shure alternative when I got them and work great.  Pretty rugged too.  Got ripped through the air 50 feet while attached to a mic stand during a storm once, and survived!

There are even cheaper alternatives if you look into the knockoff stuff online.  I'd be a little leery about any of the stuff with amplifiers or distribution, but for the basic antenna part, there's not a lot of risk going with the cheapies.

If you're REALLY tight on a budget, you can even build your own if you so desire. It's not complicated. You just need to build a circuit board with traces the right lengths and add a connector.  Probably could build one for under $20.
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Re: Do I need a antenna?
¬ę Reply #8 on: September 21, 2022, 02:17:05 AM ¬Ľ


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