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QRX100/TRX900la range?


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Sorry to go OT, but.... 

Would something like the remote antenna for the TRX900/STA150 work? Not the same actual thing, but has anyone tried to remote whips to your shoulders? Would that even work?

I've seen what Rado has with the SNA600 on the harness (was that a secret?), and that seems to get him a nice improvement in range over whips in the bag. Again, is it really just that he has his receiving antennas up and away from everything else? 

I haven't set up any sort of bag antenna combining thing yet, so I'm paying attention to what works for people. 

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jp: " has anyone tried to remote whips to your shoulders? "

yes, frequently.

and, as has frequently been mentioned here, the results are typically pretty poor, as there needs to be a counterpoise.

while this is true on paper in the real world using an extension cable on the transmitter works very well.
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while this is true on paper in the real world using an extension cable on the transmitter works very well.

 

Transmitter or receiver? I've used the Lectrosonics remote transmitter antennas (the ACOAXTX) for all kinds of rigs (cars and rowing shells mostly) and had great results. I realize the physics on a receiver is different though.  

 

So for most bag work, the range of my TRXLA2 & QRX200 is fine with the whips. I don't know what will happen if I get (some brand of) antenna distro and use whips coming out of it (like say a MicPlexor). If the range is the same, it would work for a lot of situations I have been in recently. *IF* I need more range, to then switch to some sort of omni receiving antenna is an option. That would also mean I am cabled up to be able to quickly switch to a set of fins for something like a driving scene, or a case where I need more range in a specific direction. That's also a plus. 

I'm not wholly opposed to something like what Rado is running, but in my experience so far, the range is ok with stock whips. The science might not seem optimum, but if it's getting you more range, then it is fixing some other problem that's not being factored in. We can debate the math all day, but if the equation is missing some numbers, then it's not the whole picture anyway. 

I realize it's a tough problem because everyone has a different bag setup. Different powering sources, possible cables with a bad shield etc etc, so 

 

Time to do some experiments! 

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Transmitter or receiver? I've used the Lectrosonics remote transmitter antennas (the ACOAXTX) for all kinds of rigs (cars and rowing shells mostly) and had great results. I realize the physics on a receiver is different though.

So for most bag work, the range of my TRXLA2 & QRX200 is fine with the whips. I don't know what will happen if I get (some brand of) antenna distro and use whips coming out of it (like say a MicPlexor). If the range is the same, it would work for a lot of situations I have been in recently. *IF* I need more range, to then switch to some sort of omni receiving antenna is an option. That would also mean I am cabled up to be able to quickly switch to a set of fins for something like a driving scene, or a case where I need more range in a specific direction. That's also a plus.

I'm not wholly opposed to something like what Rado is running, but in my experience so far, the range is ok with stock whips. The science might not seem optimum, but if it's getting you more range, then it is fixing some other problem that's not being factored in. We can debate the math all day, but if the equation is missing some numbers, then it's not the whole picture anyway.

I realize it's a tough problem because everyone has a different bag setup. Different powering sources, possible cables with a bad shield etc etc, so

Time to do some experiments!

on the transmitter.
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Transmitter or receiver? I've used the Lectrosonics remote transmitter antennas (the ACOAXTX) for all kinds of rigs (cars and rowing shells mostly) and had great results. I realize the physics on a receiver is different though.  

 

So for most bag work, the range of my TRXLA2 & QRX200 is fine with the whips. I don't know what will happen if I get (some brand of) antenna distro and use whips coming out of it (like say a MicPlexor). If the range is the same, it would work for a lot of situations I have been in recently. *IF* I need more range, to then switch to some sort of omni receiving antenna is an option. That would also mean I am cabled up to be able to quickly switch to a set of fins for something like a driving scene, or a case where I need more range in a specific direction. That's also a plus. 

I'm not wholly opposed to something like what Rado is running, but in my experience so far, the range is ok with stock whips. The science might not seem optimum, but if it's getting you more range, then it is fixing some other problem that's not being factored in. We can debate the math all day, but if the equation is missing some numbers, then it's not the whole picture anyway. 

I realize it's a tough problem because everyone has a different bag setup. Different powering sources, possible cables with a bad shield etc etc, so 

 

Time to do some experiments! 

Hi Johnpaul,

The Lectro ACOAXTX is not just a wire at the end of a cable, i.e., like a 1/4 wave whip connected to an SMA. The shield on the ACOAXTX is folded back over the last 1/4 wave of the feed-line coax under the shrink tubing. That forces a balun construction that is one arm of a dipole. The "whip" section , formed by the 1/4 wave center conductor, is the other half of the dipole. So the coax antenna doesn't need a counterpoise since it is a dipole. It is not a great antenna but it is better than a whip on the end of a cable.

We even give "how 2" instructions to roll your own if you don't want to pay the exorbitant $55 retail.

Best Regards,

Larry Fisher

Lectrosonics

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I'm wondering why no one makes whips that are designed this way (dipole whip).  I realize they would be twice as long, but, with this discussion as an example, there may be a market for them.

Hi John,

If the whip is mounted on a receiver or a transmitter, the unit acts as the counterpoise (ground plane), i.e., there would be no gain using a dipole directly on the unit. In fact, it would not work as well as the whip.

Best,

Larry F

Lectro

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Thank you Larry! Always informative!

I have a few ACOAXTX antennas and just assumed it included some secret blend of pixie dust mixed up by unicorns under a full moon.

The new PD formulation can tolerate as little as a half moon. We have to use younger unicorns though because they can see better in the half light. This is causing us all kinds of age discrimination problems.

Best,

Larry F

Lectro

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Have you updated the Firmware to the new modulation? It has VASTLY improved range. The few times I used antenna distro with Zaxcom Blue sharkfins, my range was increased, and I was able to successfully get signal through 4 walls over 50ft no problem. YMMV.

 

-Chase

While I love my zaxcom stuff, 

 

I updtaed my firmware and have both units running int he XR mode.   I get very similar performance,  dropouts withint 40ft...  sometimes I can go a couple hundred feet it's very random,  but i've had plenty of inside 40ft dropouts...   

glad they have the new version 2 stuff out, 

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BTW, here's the episode that covers the day spent filming with the Zaxcom gear:

 

 

From about 7 minutes in (I wasn't there for the breakfast stuff, which was camera mic audio).  Overall, I'm quite happy with how it all sounded.  Thanks to the Rycote windjammers, there's almost no wind noise, and the COS11's picked up their voices perfectly.  The Zaxcom units managed to handle everything from the whisper of the bicycle chain to the screams of pain as they went up the steep bits.

 

BTW I wasn't allowed to poke holes in their jerseys, so that's why the cables are visible :(

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BTW, here's the episode that covers the day spent filming with the Zaxcom gear:

 

 

From about 7 minutes in (I wasn't there for the breakfast stuff, which was camera mic audio).  Overall, I'm quite happy with how it all sounded.  Thanks to the Rycote windjammers, there's almost no wind noise, and the COS11's picked up their voices perfectly.  The Zaxcom units managed to handle everything from the whisper of the bicycle chain to the screams of pain as they went up the steep bits.

 

BTW I wasn't allowed to poke holes in their jerseys, so that's why the cables are visible :(

Sounds great,  how conceiled were the mics under the jerseys?,  since they have tights on, how'd you go about mounting the tx's?

 

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Most audio was from the TX's internal recorders (some of the audio at the rest stops was probably from my mixer as I was plugged into the camera filming them talking).  Apparently it took about 12 hours to do the mix, I don't know what exactly that involved but I suspect a large part of it was the Gopro footage (no TC).  Everything else, bar the drone and occasionally the Sony F5 that shot the slow motion (they lose TC when going to slomo) was synced up from my mixer.

 

The mics were positioned just below where the zips ended, held in place with Tram vampire clips (the cable ones).  This wasn't adequate and they occasionally came loose (probably when the male riders opened their jerseys completely, flapping around in the wind), so we improvised and secured them a bit better with some tape.  As the riders sweated more that eventually became useless, but the tight fit of each jersey did the trick anyway.  I wanted to run the cable down the jersey, around the back and into the rear pocket via a small hole I would have cut, but I was told that wasn't an option.  Elasticated belts weren't fair on the riders, clipping the TX's onto their bib shorts wouldn't have been safe and the producer was happy with a bit of cable showing, so that's what we went with.  Cycling jersey pockets are really deep so there was no real chance that the TX's would fall out.

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