Actually I did have it in an armpit.

Anyhow, I'm reasonably happy with the unit - think it will be more than good enough for what I need.

If it sounds good, and your distances are modest - that's all that's needed. It just gets harder when you have more channels on the go. For one system, it's rare to find an unusable one. I found a couple of my old ones the other day and they must now be 25 years old, and were not the most expensive when new - they still work and sound fine.

Thanks again Jim

I'm sure that manufacturers also take this into account when designing a system so make sure that the system will actually work when the transmitter is on a person. I usually always try to use the left jacket pocket if it exists as the groom at a wedding is on the right of the bride (from the camera POV) so at least the transmitter doesn't need to punch thru a heap of body fat as it's on the side of his jacket closest to the camera. I'm also 99% of the time only less from 20' from them as any further away means I am highly likely to get blocked.

The bottom line here is that it works fine even in armpit mode at reasonable distances which is good enough for me!!

Yeah, I also had a groom already miced up at a wedding and he decided to visit the bathroom and of course I could hear the whole procedure on the camera but wasn't recording yet ... it does show that transmitters work pretty well even in unusual conditions

Chris

Hi Chris

I know it wasn't a very scientific test but it gave me a chance to play with the unit a bit more. I think my conclusion is that it should work well in just about any orientation - maybe even clipped to the belt in back to avoid bulging pocket syndrome. At the distances you'll be working I don't think I'd worry much about the wearer's position relative to the receiver or where on the wearer the transmitter was placed.

I'm rather favorably impressed with the unit and it seems to be a good price performer as well. I started out thinking it would be hard to find something under $500 that would be good enough for what I need, but I was wrong.

Chris - you can't design a system to be better when worn on a person - as this is fundamental in the majority of use. As I said, the aerial system on the pack is always a compromise, and there is no international standard for a 'person'. Some people do seem to be radio nightmares - there is very often, in a multi-system install one cast member who just has radio issues. They are not necessarily big, or more fatty - which you would kind of expect to soak up more RF, leaving gaps in the radiation pattern. Sometimes they are just the same size the ones who's systems work? Sweat does seem to play a big factor.

Without some kind of standard, we should place little emphasis on a test that seems to suggest product A is better than product B, or C. The factors essential to making this determination have not been measured in these user reports. Power output, aerial efficiency, and receiver sensitivity. The last one is quite important. Sensitivity can often be increased in a design, but usually at the expense of selectivity, which may not matter in a rural location with just one transmitter running, but in a busy city, could be a killer flaw. In RF testing, performance on strong signals is often pointless, it's how they cope with low RF level, and strong sources on the next channel that matter.

Probably worth also keeping in mind that attenuation gets worse as the frequency rises - so we should be complaining that 2.4GHz kit keeps dropping out, but of course, it doesn't.

By all means test the audio quality, and construction - but don't get sidetracked by RF performance based on observation, not measurement - it's far more complex than it appear to be. The only real rule should be to make the path length as short as it can be. You can talk to the space station perfectly well on RF levels similar to radio mics - because there is nothing in between!

Thanks Guys

As long as it works and we care with placement I see no issues. The only issue I ever had was with the Azden 330 which was the dual receiver and that had multiple dropouts inside a Church. My old Azden L100's have no issues except our Government has re-allocated the frequencies so I have no option but to change and with more re-allocations in the pipeline the 2.4GHz AT units were attractive hence all the questions.

We are into our Winter season in a week's time with no weddings scheduled for 10 weeks as it's cold and wet so I will have a bit of time to test and decide. All the advice is greatly appreciated of course and Jim's practical tests are of far more use to me than a corporate sponsored "review" .. especially kind of you Jim!!

Chris

Thanks for the kind words. It really wasn't much of a test and it gave me an impetus to familiarize myself with the unit.

One thing I don't like about it (at least on the small camera top receiver) is that the labels on the switches and ports are just molded into the black plastic and they're small - and my eyesight is awful so without a strong light it can be difficult to read. I actually looked at the instruction sheet and just memorized what was where. Probably not a problem for "youngsters" though!

That's also my issue! I normally need reading glasses for small print but have an extra lens on the camera's viewfinder so I don't need them ...that doesn't help situations like yours and I have had that myself and you either need to have a pair of reading glasses hanging around your neck or struggle to read and like you end up memorizing where switches should be set! Old age is a bugger and what especially annoying is that with my still cameras I have dioptre settings on the viewfinder but nothing to magnify the LCD screen so checking what you have shot is tricky if you cannot see it in 20/20 vision

Yes, size matters!

I preordered a 7" Sound Devices video recorder - I need the big screen. It's absolutely hopeless trying to use the (CRAPPY!!!!!) viewfinder on the C-100. The LCD screen is nice enough - but not outdoors here in the Arizona desert!

Come to think of it maybe it's more a matter of age than size.

A quarter wave antenna is pretty efficient, but should really have a ground plane to work against.
I've always assumed that the manufacturers hope that the ground plane of the PCB inside the case, capacitively coupled to the wearer's body, would somewhat serve as the ground plane. Of course that doesn't eliminate the numerous variables that have been mentioned.

Bringing the antenna close to an absorber - as in the human body, impedes the efficiency even more. The side away from the body will radiate, but the side near to the body will propagate poorly because most of the energy is absorbed by the body - which is mostly water
More than that, being coupled to a human body will most surely detune the antenna, which will cause more reflected power back to the transmitter final stage, and less power reaching the antenna. (And of that "less power" much is then absorbed, as stated above, so the loss of total radiated power can be very significant.)

and very often sweaty - and the salt is of course a conductor. It's amazing that an antenna in a pocket in an armpit emits anything at all.
I've never performed a scientific test of this (thank God) but I suspect that the effect of surface sweat is minuscule compared to the effect of all the salt water contained inside the body. After all, we are not placing two conductive electrodes in electrical contact with the surface sweat. The effect here is one of absorption of the electromagnetic field radiated by the [insulated] antenna.

@Chris

I don't worry too much about not seeing what still I've shot on the display - I mostly use film:<) Large film at that (and so does Greg - we're both on the Large Format Photography Forum!) and don't actually see the result for days to weeks. Digital for video, film for pictures (although I do have an original Canon 5D as well)

It's great fun when I'm out with a group and ask the waiter/waitress to take a photo and hand them a 4 x 5 Graphic with a huge flash gun (flashbulbs) The reactions can be priceless. I've seen people stare at the back of the camera looking for the display!

I've never performed a scientific test of this (thank God) but I suspect that the effect of surface sweat is minuscule compared to the effect of all the salt water contained inside the body. After all, we are not placing two conductive electrodes in electrical contact with the surface sweat. The effect here is one of absorption of the electromagnetic field radiated by the [insulated] antenna.

I too have seen no data on the effect of sweat, but in practical terms, sweaty people increase the nulls. I can't say it's the salt content and could just be the water, but so undies in theatre try all sorts of things to get the packs away from them. The linen bags most of us use to attach them get pretty nasty on the sweaty people, and one. Olleague swears by sandwich bags with the pack in tucked inside the pouch.

Design wise I suspect the output tuning is always less than optimum. Very little point aligning for optimum when the aerial system is rarely going to be close to 1 to 1.

Too many people simply try to run systems with tx and rx too far apart, expecting too much. After saying all this, the odd thing is that I have never had a dropout with my digital systems in the same space my G3s do occasionally have problems with.

@Chris

I...

It's great fun when I'm out with a group and ask the waiter/waitress to take a photo and hand them a 4 x 5 Graphic with a huge flash gun (flashbulbs) The reactions can be priceless. I've seen people stare at the back of the camera looking for the display! Images of Weegee at work or the opening of the old Bob Cummings TV show flashing in my head

I'm certainly no audio engineer but I have noticed the I get better performance if the antennas are in free air ..


This is essential - if an antenna touches the body you can get about 70dB of signal attenuation.

Getting the antenna just 1cm off the body will give you back most of this, with just minimal attenuation.

This is why transmitters are often put on with the antenna facing down, to get it away from the body.

I've seen people stare at the back of the camera looking for the display!
That won't work too well once the sheet film holder has been slid into place.

Maybe someone should make an app that rotates the image on a cellphone display by 180º to simulate using a cut film camera. At the very least it would drive most people crazy.

Progress report - declaration of success!

I had the good folks at Markertek make up a cable to go from XLR to the input of the AT System 10 transmitter, and got a Switchcraft box to take the 1/8 stereo Tape Out of the 702 to Balanced Mono XLR.

Started something playing on my monitors, hooked the mics up to the 702 and Tape Out to the transmitter via the Switchcraft box and the Markertek cable, and Voila!!! I have a nice clean track 100 feet away without running cable.

Remembering that all I'm looking for is a sync track to three balcony cameras, I think it will work. We'll see how it goes 6/6 at the concert. (And just in case I'll use the clapper board before the show starts.)

By the way, I'll take the output from the receiver into a Motu interface and distribute it to all the cams, so I only need a single wireless channel

Just reporting back on results

I recorded a 2 hour concert today. The System 10 worked flawlessly and I never heard a dropout or a Snap Crackle or Pop. It just worked

Great Jim

It's my next purchase for the new wedding season without a doubt! I'm treading on dangerous ground using my UHF units on frequencies that have been re-allocated ...very soon I will get a digital radio station coming thru load and clear instead of bridal vows!!

Chris

Jim - never fall into the mind set that a system is bomb proof. None of them are. They all work brilliantly until they don't. Location is critical. When I used to do theatrical touring shows, we'd have the same system every night, in similar capacity venues - usually 800-1500 seat size. One night all would be perfect, the next night, pops, hisses, warbling sounds, major dead spots. The best you can do is mount aerials in the clear - split receive aerials apart if possible, and cross your fingers. I suspect that if we could see RF (like Geordie in Star Trek) we could solve many problems instantly, but all solutions or reductions in severity are down to experience and witchcraft!

I was pretty happy with the way it all worked - up to the point where SOMEONE seated near the 702 managed to switch it off mid-concert! I've never had anything remotely like that happen. I always have someone guarding the recorder, but yesterday I was REALLY all by myself. I usually have a backup mic/recorder set running but of course this was the day the janitor didn't open the hall until 30 minutes before the start of the program and I barely had enough time to get one pair of mics in place before the doors opened - I was still cabling things together as people started coming down the aisles.

One of the orchestra members had a recorder running so we'll have at least SOME audio for the whole concert.

All things considered, I'm more worried about something like this than a few dropouts in a sync track.

Did they inadvertently knock the power loose or did they literally switch it off? If the latter, that's pretty astounding... Perhaps the ultra-bright Sound Devices LED's made them go temporarily insane!

Well - when I saw it was off I just hit the power button and it woke up so power wasn't an issue - it was running on battery and the battery looks good for another hour or more. CF card had enough room for a couple of more concerts left so it wasn't the card filling up.

The 702 is pretty well designed to protect against truly inadvertent on-off button pushes - you have to want to power it off to make it stop. Haven't updated firmware recently and I've used the recorder for enough years to trust it. I "always" mount a Sony PCM D50 on the mic stand "just in case" but the thundering herd was on me before I could get it set up.

Could it have been a glitch of some kind? Of course, anything is possible. But, statistically, why would a glitch hit precisely in the applause between two pieces instead of in the middle of a piece. Sort of like dropping a dime and having it land in the crack between two sections of pavement. Possible, yes, likely, no.

The final file is only 1.3GB so it wouldn't have been trying to do a file "split"

It's a mystery.

One thing I know for sure is that I need more than 30 minutes between the doors being unlocked and the "start of festivities." They keep adding new events before the main concert - like a children's 30 minute concert and most recently an instrumental "petting zoo" for the kiddies. Nice idea - they have a bunch of players with their instruments and the kids are encouraged to touch, blow, whatever. The Timpani were the most popular because 4 year-olds like to make noise. I think it's actually a really good idea, but it's impossible to set up when a horde of kiddies and parents is milling around underfoot right where the mics need to be placed.