JTS wireless mics

[paulears]

how workable would it be to use passive TV splitters such as http://www.screwfix.com/app/sfd/cat/pro.jsp?id=79447# and decent 75 ohm TV aerial cable http://www.screwfix.com/app/sfd/cat/pro.jsp?id=37838 ?

This would work though not ideal. The 4 way splitter would have a loss of approx 7.5 dB, cable loss at UHF around another 6dB and say 0.5dB for mismatch. Total 14dB. With the aerial on stage assuming a decent dipole then the extra pickup would likely balance this out. If your receivers are diversity then you should duplicate with an aerial at each side of stage.

 

Yup, I'm aware that it's not the perfect solution, but it's still only a tenner's worth of a pair of splitters, plus I've already a bundle of decent spare TV cable - this compared with over £250 worth of dedicated splitter makes it worth having a quick go. Obviously it'd be doubled up for diversity. I figure I've got nothing to lose, if it works we're quids in, and if it doesn't I've only wasted about a tenner and go out and buy the appropriately specced branded distribution amp.

 

Thanks for the input.

 

 

On paper, budget tv passive splitters look great - the reality is that the spec gets wrecked by shoddy internal construction, and the losses inherent with tv type conenctors means the 'real' insertion loss is much greater. Apart from the losses, the isolation between outputs is pretty poor, making a cable fault to one receiver, severly limit the performance of the others.

 

That said, I'm actually a fan of passive splitters, because actual signal level is rarely the issue with rf systems.

 

We had quite a few offshore telecoms/data companies in the area and I bought a surplus lot of astec 4 output pasive splitters. TNC ins and outs, low insertion loss accross the 400-1000Mhz range. I've compared them with the powered adu I have and there is a small loss - less than one bar on the receivers. they are tough industrial devices and are totally immune to the problems associated with powered amplifier/splitters.

 

Jim Brown probably churns out the best advice going, and the benefits of the 'wrong' impendance cable. Connectors need to be chosen with care, though. the central pin size of 50/75 ohmversions is different. cross plugging 50 ohm plugs into 75 ohm sockets damages the socket, and a 75 ohm plug in a 50 ohm socket may be slightly loose. This is a common issue with BNC types common in rf and video systems.

[Alec]

Finally got my set of 2 JTS 901 lapel mic systems plus a handheld TX.

 

Initial impressions:

- Can't believe the build quality for the price! Seem as solid as anything.

- Sound quality of both lapel mics & handheld is great.

- Handheld appears very feedback resistant in my typical usage scenario.

- Range is great. In our stone church it made it all the way through a few thick walls down some corridors - even did pretty well with no antennae connected!

- Love the usability - just the on/off switch exposed, with the other settings hidden from the user. Can turn the on/off switch into a mute switch if required.

- Great packaging. Carry case has foam sections precut to allow lots of accessories in one box (e.g., I can fit both bodypacks & the handheld into a single case). Love the fact that they provide 7 different coloured endcaps for identification rather than making you pay for them as extras.

- Love the bodypack design for battery changing - no lost battery covers again!

 

Reservations:

- Bodypacks are quite chunky

- My lapel systems came with the subminiature CM-201 omni which sounds great, but I had expected the cardioid CM-501. Should get this resolved in the next couple of days.

 

But generally, a huge hit for me. A big thanks to whoever first pointed these out a while ago!

[Alec]

Having run my 3 new JTS systems over christmas, I can certainly confirm that I'm very pleased with them.

 

Found two weaknesses with the lapel mics (CM201) supplied. The windshield will fall off at the drop of a hat - easily fixed with a careful drop of Copydex. The tie-clip relies on a friction fit to hold the mic cable, and we've already had a speaker lose one (think the Copydex needs to come out again). Need to see how easy it is to get a replacement, but at only GBP 20-30 for the whole mic with clip, it's still a bargain. Otherwise, dead chuffed with these mics.

 

Back to my antenna distro question again. Who's got a JTS UA-900 who can answer a question - are the antenna inputs on the front panel only, or rear and front panel? If I get one of these, I want to run the antennae into the rear panel rather than the front, but am wondering if I'll be scuppered by this arrangement.

[boswell]

Can anyone give me the URL of the JTS Website, I've searched and can find dealers but not JTS themselves

 

TIA

[paulears]

jts manufacturers web site

[boswell]

Thanks Paul, it was the .tw that threw me!

[david.elsbury]

Who's got a JTS UA-900 who can answer a question - are the antenna inputs on the front panel only, or rear and front panel?

We just unplugged the BNC cables from the front sockets and plugged the antennae straight into the distro. I'm pretty sure we were using the model you are... it's just a little bit of a pain, as the BNC's are very close together.

 

David

[Alec]

We just unplugged the BNC cables from the front sockets and plugged the antennae straight into the distro. I'm pretty sure we were using the model you are... it's just a little bit of a pain, as the BNC's are very close together.

 

So, as I'm still left unclear, the distro has got inputs on the rear panel? Am I then right in thinking that the front panel connectors are effectively "extenders" from the rear sockets?

 

You're right on the hassle of tightly spaced BNCs, though. Canford sell a tool to save your knuckles if you're having to do this regularly.

[Pete Alcock]

Hi AS8602,

 

Glad you're pleased with your JTS kit! The CM201 is a superb mic and I find I don't need the windshield - it's actually better without it, as the sponge makes a noise as it rubs against clothing.

 

Regarding the antenna distro, it comes with 10 short BNC to BNC cables. 8 connect to the aerial inputs on each of the four receivers, and the other two are to connect the inputs of the distro to the antenna mounts on the 1u front panel. You get two "back-to-back BNC sockets" that fix with a nut on the font panel - rubber duck antennae go on the font, the extender cables to the aerial distro go on the back.

 

You can of course put the rubber ducks stright on to the back of the antenna distro. The really neat part is that the antenna distro has 4 DC power outlets (cables supplied too) to feed the four receivers, so you can throw away the wall wart PSUs. The whole thing works like a charm. I've posted this before but here's one I made earlier.

 

http://i2.photobucket.com/albums/y24/petealcock/RadioMicRack.jpg

 

Pete.

[Alec]

Finally plumped for a JTS UA-900 which I picked up last week, rather than a DIY approach.

 

Works a treat with 4 pairs of antenna outputs and one pair of inputs, which can be extended to the front panel, plus 4 15 V outputs to power the receivers. All cables are supplied, which makes a pleasant change.

 

Took only minutes to hook up in a static install rack. May run antennae to more sensible location but right now, just have the 60CM cables poked through the rack and the rubber ducks dangling off them. While it's not quite "right", and will be addressed at some point, tests have shown no problems with reception.

 

The pop shields are now off the CM-201 lapel mics having both failed to stay on despite Copydex modification - you're right, they're fine like that. Sorted out five replacement clips for only GBP 1.20 each, and the original lost one was promptly found!

 

And the transmitters are *still* showing all battery segments even after over a month of regular use!

 

I'm a happy puppy, and all credit to Disco Studio who have been very helpful in my recent purchases once I overcame their name!

[Steve_Hole]

I have recently purchased on of the JTS US901D/A handheld for use in my church and I am very impressed, sound and build quality are superb - thanks for all the comments from people who have already purchased them. <_<

 

However, the unit I have seems to have a fault - when the battery indicator is flicking between 2-3 bars or even 1-2 bars as the battery runs down, there is a clicking on the audio. As soon as it stops flicking, the clicking stops... takes about 10 seconds normally...

 

I'm not using rechargeable batteries and I am running balanced between the unit and my mixer (via a 10m XLR-XLR lead).

 

Does anyone else have this problem or is a fault with my system?

 

Thanks in advance for your help

 

Steve :)

[dbuckley]

The other issue is why do you need to run such long aerial cables? The loss down 25m of cable will probably cancel out any advantage of moving the aerial 25m closer!

Not so.

 

It is true that the signal levels may be similar in the two situations, but that is not the end of the story. More important than the absolute signal level is the relative signal levels at the antenna of the wanted radio mic signal and other interfering sources, whether on frequency of elsewhere. Losing level in the cable where there is no added interference is less damaging than losing level through air distance where its all a crap shoot.

[discostudio]

I'm a happy puppy, and all credit to Disco Studio who have been very helpful in my recent purchases once I overcame their name!

 

Thanks for the plug, and I'm still coming to terms with our name, 8 years later!

 

The JTS 901 systems are truely amazing and, with regard to the battery problem, that is a fault, not an intermitent battery problem, send it back and JTS/Proel will be happy to replace it.

 

Speaking of JTS road kits has anyone noticed the new US-1000 series kit:

 

http://www.discostudio.co.uk/images/shopimages/4899m.jpg

[cedd]

As the title suggests! Anyone using the JTS range? If so how do you find them? They look really too good to be true for the price. Certainly my handheld performs well.

 

Moderation: Thread merged with an existing thread discussing this very issue. Please use the "search" function before starting a new thread.

[Rob_Beech]

Whilst its been said before the overall view seems quite positive.

 

I use these units quite regularly now (only the Hand Helds although I have a further HH and a lav. mic on their way).

 

can't fault them. absolutly brilliant.

 

Re Simons post (months ago). it took me a while to realise you could turn down the sensitivity, and I still think they are pretty hot even at -30db. but other than that, really good mic.

 

Rob