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Lectrosonics SNA 600 Antenna


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I have been doing alot of antenna research the last few weeks and think this is the best choice for me here is my situation:

I do mostly fast pace reality work with 4-6 wireless plus a zaxcom hop. I sometimes need to set up farther away from where we are shooting then I would like. I need something that is easy to transport and quick to set up to give me more range. I am in blocks 27 and 21 so I was thinking about buying two of one for each block to increase my range I like that they fold up and the price is also good. I would like some user feedback or suggestions on a better set up.

Thanks

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They work really well!

Are you working out of a bag, or do you have a cart/table setup where you can mount it on a stand?  If you are stationary, why not go for a more directional antenna?  Do you plan on using one for the Zaxcom Tx as well?  I have been thinking about doing so for the right situation but haven't done so yet.

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Whitney and Phil,

Between the venues and the SNA's it's 50 ohm RG-8U. I use a pair of SNA's - (diversity) and the length of the antenna arms is set to the bandwidth of Block 21 - 22  (537.600 - 588.700). Or approximately 3/4 the way between the 550 mark and the 600 mark.

Download the PDF file I've linked to.

http://www.lectrosonics.com/catalogs/UniversalCatalogPages/sna600td.pdf

Oh, the second set of SNA's is a leftover from the days of two racks of 411a's.

RL

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Whitney,

PSC does have a smaller unit that might work.

(http://professionalsound.com/specs/multi.htm)

p.s.

PSC has an awesome one called the MultiMax RF (http://professionalsound.com/specs/multimax.htm) I used this one on my last Reality Show.

p.s.s.

I'm a SNA600 fan too.. but you have to keep all the Lectro's in the same blocks because of the settings on the antennas.

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" Which RF splitter combiner "

" Do I need one or two antenna per block "

" I need something that is easy to transport and quick to set up to give me more range. I am in blocks 27 and 21 "

let's see,  who could you ask??

Antennae for wireless is a topic that is frequently discussed, so doing that research (like doing searches, and contacting experts (you know what I mean!!) is really important

the user experiences and comments part: not mentioning a lot of the obvious stuff, the SNA's are reasonably priced and effective; they are more narrow band than LPDA's so less effective for wide frequency (multi-block) splits and in those cases, also consider there is also interaction amongst antennae possible.  There is a lot of physics at work, and many would say Voodoo is involved, too, so individual results are always varying, and even experienced folks will have different subjective opinions on what was best, and that can change from day to day, and location to location.

Ham radio operators (amongst other groups) have been experimenting with antennae for decades, and still are today; there are hundreds of workable choices,  and there is no single best alternative!

in my own case, in circumstances similar to what you describe, I have had great success with the "coaxial dipole" antennae, which seem, in practice, to provide an improvement over the Lectro whips, although I have also found that making my own 1/2 wave whips also seems to provide a slight improvement over Lectro's 1/4 wave whips as well.  for diversity, I often use one 1/4 wave and one 1/2 wave whip, or one coax dipole and one whip (either size), and am pleased with the results, although "experts" seem to think that for Lectro's diversity system, matched antennae pairs are preferred. also bear in mind that free space and other objects -including equipment and people- near antennae affect their performance. I have a supply of SNA's available, and when appropriate I really love my Yagi (not LPDA!) antennae.  a quality UHF single splitter's loss is usually acceptable, if one makes a noticeable difference, there is usually something else wrong!!

I try to use the lowest loss coax possible for any situation, and prefer preamps before long runs of any coax (and I have done some major facility installs!)...and when possible I prefer the "preselector effect" of a narrow band preamp.  As I have mentioned before, I have never failed to get several systems operating on any block, anywhere! thus I use 2 adjacent blocks, a third adjacent block for IFB (my primary block is the one in the middle!) and eliminate any overloading and IM problems by physical separation, as even inches make a significant difference.

I suggest the ARRL's (www.arrl.org) antenna handbook (updated every other year, that is how variable antenna information is!!) for more information on antennae, and the appropriate HAM radio band (I've been on VHF and UHF for many, many years!) is the 450 MHz band...

finally, an excellent place to discuss with users, Lectro antennae and their implementation would be the Lectro discussion group

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  • 8 years later...
On 2-8-2017 at 11:47 PM, Trey LaCroix said:

I use them with my block 19 and 20 receivers just fine. I think they cover 100mhz from the center frequency.

I was thinking so, but wasn't sure. Perfect!

5 hours ago, Jonathan Michael Lau said:

thanks!

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I use the SNA600 almost exclusively (two for diversity), and they work really well. I also use them for my comtek transmitter antennas by adding the 216mHz extensions (https://www.trewaudio.com/product/remote-audio-miracle-whip-mw216-kit/). Early on during my last show I was having dropout issues, so I switched to two shark fins, and still had the dropout problems. The problem turned out to be a faulty IFB transmitter, so I changed that transmitter, switched back to the SNA600 folding dipoles, and all was good.

 

Granted, the shark fins have more gain, so in theory you can be further away, which is sometimes the case, IF they are pointing the right direction. For cart use, eventually they WILL be pointing the wrong direction, which will result in a decrease of gain compared to the folding dipoles. Also, when the actors are close to your cart (which is not all that unusual), the 8dB of gain from shark fins can overload the receiver input, causing audible problems. For these reasons, in my experience, portable shark fins are less reliable for cart use than folding dipoles. [edited Aug 7, 10am PDT ]

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  • 2 years later...
On 7/4/2009 at 7:36 PM, Richard Ragon said:

Whitney,

 

PSC does have a smaller unit that might work.

(http://professionalsound.com/specs/multi.htm)

 

p.s.

PSC has an awesome one called the MultiMax RF (http://professionalsound.com/specs/multimax.htm) I used this one on my last Reality Show.

 

p.s.s.

I'm a SNA600 fan too.. but you have to keep all the Lectro's in the same blocks because of the settings on the antennas.

 

 

 

Ive got lectros in block 20, 24, 26, 29. How should i set a pair of sna600.  Hss anyone tested the venue rf diversity dipole fin combo too ?

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The sna600 has a 100 MHz bandwidth around the center frequency (as printed on your antenna). So you're not really using the right antenna for this wide of a spread of frequencies. The roll off is gradual, but with a range of 512 mHz to 760 mHz that's a 250 mHz spread. Use a sharkfin antenna as that is wideband 

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On 10/18/2019 at 4:23 PM, Shastapete said:

The sna600 has a 100 MHz bandwidth around the center frequency (as printed on your antenna). So you're not really using the right antenna for this wide of a spread of frequencies. The roll off is gradual, but with a range of 512 mHz to 760 mHz that's a 250 mHz spread. Use a sharkfin antenna as that is wideband 

setting the sna 600 in "the middle "of those blocks wouldn't be as efficient like a 470 - 790 shark fin?

 

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A shark fin is a Log Periodic Dipole array. These antennas have multiple dipole antennas and each pair is sensitive to a tuned frequency based on antenna length and wave length (full, half, quarter) plus and minus some, but the center frequency is the best. They are wide band because there are multiple dipoles that when combined gives you broad spectrum sensitivity.
 image.png


An SNA600a antenna is only a single dipole and therefore is only sensitive around the tuned frequency (plus the roll off area) 
 

image.png

A dipole is like a whip antenna in that it is tuned for its intended frequency use.

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6 hours ago, alidav said:

Copy thanks, but having an sma distro  for indoor and or bag recording a pair of dipole antennas tuned on the middle of all my blocks  should give me at least a better performance of own whip antennas. What do you think?

 

I think you haven't paid attention to what I've posted.

 

An SNA is 100mhz wide. Your gear is nearly 250 mHz wide. The SNA will attenuate the signal lower than what your whips do outside the set frequency.

 

An antenna distro will just make the one antenna available to all of your receivers, it doesn't change the physics of the antenna attached to make it work better.

 

Using an SNA tuned outside the frequency of your receivers as your antenna will preform worse than using whips.

 

The correct antenna to use is a wideband antenna OR antennas (whips) tuned to the frequency of each receiver, an SNA is NOT a wideband antenna.

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  • 1 month later...

I'm prepared to have this filed in the "stupid question" column, but just to be SURE I understand:

 

Say I have a Block 22 Lectrosonics IFB, two Block 20 SR-B, and 2 block 20 UCR-411a's in the same bag.  Is it acceptable to use two passive combiners along with two passive sharkfins or sna600a's for the receivers and the transmitter at the same time? In one combiner I'd have 4 receiver antennas, and into the other I'd have the other 4 receiver antennas + the one transmitter antennas. Would that put the Voodoo RF Gods in a negative disposition?  Tx and Rx from the same antenna is OK? Or not so much?

 

Thanks for the clarification,

Sam

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