Radio Mic reception and channels

[Simon Lewis]

My question is what would you guys use for aerials??

 

Pete,

 

To be honest, I really wouldn't bother trying to make up an aeriel booster / distribution system. There's various issues about boosting unwanted as well as wanted signals, and given that the units you have do not appear to be too selective it may cause more problems than it solves. I would echo the advice given above - place your receivers at the stage, and tape over the controls on the bodypacks.

 

Simon

[Bobbsy]

Another vote NOT to go for the antenna booster option. Unless you go for something prohibitively expensive they'll probably introduce phase jitter which is not a big problem for something as wideband as TV but can be a big issue for multiple little channels of radio mics. When I mentioned the TV gear route, I was thinking of just a decent antenna and splitters...and good, low loss cabling.

 

Bob

[pdherring]

Ok guys, thanks.

 

So if I wanted to trial a solution with as your say decent antennas and splitters what antennas would you use?

 

Thanks

[Sound Man]

The aerials on these receivers are fixed so I can't see how you can connect boosters etc. Also they are not diversity systems, just two seperate single aerial receivers in one box.

 

Some years ago I bought one of these Gemini UF-2064 radio mics. Mine had a fault with it in that both receivers activated when I switched on one of the belt packs. Changing the frequencies on the receivers made no difference. Eventually I sent it back and exchanged it for a Gemini UF-8264 diversity system which worked quiet well. I used the frequency chart on page 3 of the manual and successfully set it up to work along side a couple of sennheisers radio mics.

 

David

[AndyL]

I have attached a PDF above that contains the frequencies and I have only found 2 that match exactly with your list (although the others are only 0.050 - 0.075 out) so I assume that we will be ok to pick these frequencies instead.

 

Err, no when it comes to intermodulation 'a miss is as good as a mile', it's purely arithmetic, so if, for example, the required frequency is 854.900MHz then 854.875MHz is not the same in a multi channel system. From a licensing perspective being 25kHz (0.025MHz) off frequency may not be an issue for a single system in isolation so long as the transmission remains within the 200kHz channel, but even that is a bit of a stretch (IANAL). The fourteen frequencies on the ch.69 shared licence are not all intermodulation free due to the history of the way they were arrived at. Depending on the quality / type of the equipment you can get anything from as few as 6 up to as many as 12 of them to work together properly at the same location at the same time.

 

The people who sell this stuff, mainly to non-technical customers, really ought to be put up against a wall and shot.

-------------------

Radio mics have become cheaply available in recent years, but really they are specialized items which require some expert knowledge to make the best use of, especially if you hope to have more than a few working together. The people who sell them, of course, don't want you to know this.

 

Sorry ...

 

Not all the people who sell radio mics take this view (my italics above)! I'll be happy to join the firing squad BTW.

[Bobbsy]

In case the OP hasn't worked it out, let me point out that AndyL works for a manufacturer of very good radio microphones. His company sells a wide variety of models, ranging from the economy end of the market, up to very high quality professional kit that deserves the title of "industry standard".

 

Their economy ranges might not be the very cheapest you can find, either online or at the likes of "Uncle Bobbsy's Discount Sound Emporium". However, by spending a little more you get extremely good technical support, including a web site listing licensing details and frequencies for countries all over the world and a downloadable programme that will work out intermod free frequency schemes for all the gear they sell.

 

Radio mics are very much a case of "you get what you pay for" and certainly the cheapest ones are not usually the best deal in the long term. A lot of first time buyers learn this the hard way and have to chalk a mistake up to experience. As a wise man once said: "With radio mics you can spend a couple of thousand pounds to buy a system that is almost--but not quite--as good as a £10 mic cable".

 

Bobbsy

[pdherring]

I really do appreciate everyones help on my issues!!! I really cant stress enough how thankful I am....

 

Ok so lets take things back to basics a little....

 

I NEED a rack of radio mics, cheep as possible, lapel based and expandable to 10+ and most importantly that will be 2012 safe.

 

What would you recommend as I am just about to throw this Gemini Cr*p out the window and invest in something that is better than (as bobbsy said) a £10 mic cable.... ** laughs out loud **, I am sure the Gemini stuff is good for a school or a presentation where you have 1 or 2 mics but when you have a professional singer as a girlfriend even if I sort the reception issues out I am never happy with the sound they produce.

 

Thanks again

 

Pete

[Jivemaster]

Terralec are a mid point supplier with both counter and mail order who have fully embraced the 2012 changeover with advice on their home page and some good looking racks full of systems. Their recent mini brochure has several choices of 2012 compliant systems.

 

Maplin of course offers some cheap radio mics especially on the VHF dereg band which may be crowded but is not affected by the 2012 changeover.

[Bobbsy]

Well, without recommending specific gear, a few points to ponder:

 

When you say "expandable to 10+ channels" how many do you need day in, day out? You may wish to consider buying a few channels of something compatible with a local rental company--then renting extra gear on an "as and when" basis.

 

For anything above 4 channels, you will absolutely need a license. The four channels are in the small chunk of dereg frequencies above 861 MHz. For anything else, the cheapest license will be the UK shared band which will be on Channel 38 after 2012 (and can be used now subject to local TV transmissions). A bit more expensive would be a site license on any spare channel.

 

I would not consider any gear that is not a true diversity system. Diversity will help a lot with your reception problems. Similarly, for multichannel ops you really want something that allows you to use external antennae and a splitter system. Cheap stuff with fixed antennae will get awkward above a few channels.

 

Anything you consider has to be frequency agile enough to use the right legal, licensed channels for the UK.

 

So, allowing for all that, I'd suggest that some manufacturers to consider would be: Sennheiser, Shure and Trantec. As per my first question, I'd probably bias my preference to consider what you can easily rent when you need extras--mixing brands can be difficult. I have a personal liking for Sennheiser but any decent brand will do the job you want...and the cheapies will just cause you grief with the number of channels you specify.

 

Hope this helps,

 

Bob

[Dmills]

You don't say where you are, but one thing to watch with the channel 38 kit is that NOT all of the uk can use it prior to 2012 (Merseyside and Cheshire spring to mind) because there is radio astronomy using that band in those areas until then.

 

This leaves us with a real problem when it comes to buying new radio kit for more then about 8 channels total (4 VHF and 4 UHF), anything we can license now will be useless in a year and a half, and we don't get access to the new space until then.....

 

Regards, Dan.

[Johnno]

I run four UF2064s (8 mics) together without any RF problems at all. I'll post you the channels on Monday when I get back to work. I use them stacked in a pile about fifty feet from the stage.

[pdherring]

Thanks again everyone your help is invaluable...

 

We are on the Essex London boarder, really the minimum is 8 mics day to day bobbsy so looking at that to begin with. I too like the sennheiser gear and have had a lot of previous experience with it, my concerns are that the models I would love to get are going to be out of our price range so any advice on there budget range and the pro's conns will help me make a better decision.

 

Johnno that very interesting as I have nothing but problems as soon as I use more than 4 (12 in total) are they lapel or hand helds as we do have less of a range issue with the hand held versions.

 

Pete

[cedd]

For me, the only viable ch38 system currently out there is the Trantec S5.3/S5.5. In your case I see little advantage in getting the 5.5. Very little of the budget kit has made the move, and for 10+ systems, I'd at least be looking to the sennheier ew100's or trantec s5.3's. Unfortunately sennheiser don't have a ch38 product yet inthe ew range. The trantc is quite a nice piece of kit though. I've used a pair and found them to sound pretty good, and the transmitters are very robust.

Careful you buy the ch38 model though.

[Bobbsy]

I too like the sennheiser gear and have had a lot of previous experience with it, my concerns are that the models I would love to get are going to be out of our price range so any advice on there budget range and the pro's conns will help me make a better decision.

 

Be careful you don't let your budget drive you into another mistake though. One of the areas where more expensive mics earn their keep though is the quality of the RF filter circuitry. As you add more channels this increases in importance--or, put another way, cheapies may be okay if you only need a couple of channels but start to interfere with each other as you add extra channels. It's not just to show off that west end shows with 30 or 40 mics pay a couple of thousand per channel for the truly pro stuff. "You get what you pay for" or "There's no such thing as a free lunch". Pick your favourite cliche!

 

Bob

[paulears]

The technical spec for handheld and lav packs is the same. The handheld often has slightly better range simply because it's not pressed up against a sweaty conductive body, and is waved around in the clear.

 

Personally, I was a very satisfied Trantec user, but moved to Sennheiser simply for the ability to programme them from the pack. I've still got some 4000 systems, and lost the programmer software in a computer change.

 

I've all my radio system purchases on hold until Sennheiser bring out their new kit. I've followed the original series and then G2, and I'll go to G3 as soon as they are in the lower band.