How Many Radio MIcs

[fincaman]

Does anyone know how many radio mics can be used in ch 38 606.500 mhz to 613.500 mhz, is there a general rule of thumbs for spacing ?

[Gerry]

10, according to My link

Cheers

Gerry

[GR1]

It depends on what radiomics you are using. Best source of accurate information will be the manufacturer's websites which will have frequency charts of frequencies which should work well together.

[Simon Lyall]

It totally depends on the make and manufacturer of the radios:

 

Sennheiser G3-300GB series for example is 12 (bank 1 channels 1-12)

Shure ULXD off the top of my head is around 40 in high density mode.

 

Which radios are you planning on using? I find Shure Wireless workbench is a useful planning tool, especially if you have multiple makes and manufacturers, you can come up with a reasonable plot with a little effort.

 

 

Simon

[Ynot]

We have successfully used all 14 freq's in our licenced list on several occasions - on EW300 G3 - with no noticeable intermod/interference.

 

Others here however I believe, have had issues.

[sameness]

Yes the ULXD can hit 40+ channels in HD mode, but in standard you will fit 16. Spoke with a chap from Shure at the warehouse last week and IIRC he said 22 was pretty good to squeeze into HD before problems

[mackerr]

Yes the ULXD can hit 40+ channels in HD mode, but in standard you will fit 16. Spoke with a chap from Shure at the warehouse last week and IIRC he said 22 was pretty good to squeeze into HD before problems

 

High density mode will require careful antenna planning as the radios will be operating at 1mW output power. The ULXDs are more immune to intermod issues than most mics due to very good shielding in the packs. That coupled with the very low power of high density mode is what lets you get so many channels to work together.

 

Mac

[mikelowe]

Does anyone know how many radio mics can be used in ch 38 606.500 mhz to 613.500 mhz, is there a general rule of thumbs for spacing ?

 

 

You'll get 12 to work together within each TV channel but if you're using channels adjacent I.e 39 and 40 then this number reduces for each cahnnel used ,

other than that use one of the manufacturers preset frquency lists

 

regards

[Bobbsy]

 

You'll get 12 to work together within each TV channel but if you're using channels adjacent I.e 39 and 40 then this number reduces for each cahnnel used ,

other than that use one of the manufacturers preset frquency lists

 

regards

 

You're basically right but don't assume the preset frequencies are planned to be intermod free. Usually they're just a series of evenly spaced frequencies. Also, all bets are off if you mix make/model of radio mic. They rarely play nicely together.

[mackerr]

 

You'll get 12 to work together within each TV channel but if you're using channels adjacent I.e 39 and 40 then this number reduces for each cahnnel used ,

other than that use one of the manufacturers preset frquency lists

 

regards

 

You're basically right but don't assume the preset frequencies are planned to be intermod free. Usually they're just a series of evenly spaced frequencies. Also, all bets are off if you mix make/model of radio mic. They rarely play nicely together.

How many mics you can get to work in a DTV channel will vary with the type of mic. The new Shure ULX-D has a high density mode where the output power is only 1mW, and they claim you can get 40ch in 6MHz (one US DTV band). This would obviously require a pretty clear RF environment. Both the ULX-D and the Shure Axient are almost intermod free anyway because of the very good shielding that keeps nearby transmitters from in to cause intermod.

 

At least with Shure, the recommended groups are supposed to be intermod free. These types of groups would be hard to use with mixed models as the RF specs are different, as are the frequency bands, but within 1 Shure model the intermod should be good. The groups also know nothing of other RF in use, which may completely change the intermod scenario. The best bet is to use one of the readily available intermod calculation programs and be sure to include all the RF you can get information on.

 

Mac

[Oldradiohand]

I've spent the week using 12 Sennheiser mics in channel 38, using the preset frequencies in the first tuning bank. I had no problems at all.

 

g

[Rob_Beech]

Bank 1 channels 1 to 12 in GB Band Sennheiser stuff works absolutely fine together as expected. I've even slotted a couple more in there without any issues.

[waster]

What were the extra frequencies you used on top of Sennheisers 12?

[smalljoshua]

Bank 11 has worked for me with 13 G3-300 series mics this week. My 14th was in Ch70!

 

Josh

[cedd]

Just for fullness, nobody's mentioned Trantec yet. I'm running 12 S5.3's in channel 38 with a further 4 in channel 70, on the suggested frequencies for each band. A friend is running 12 channel 38 Sennheiser G3's alongside 6 channel 70 G3's regularly and isn't having any problem, though I believe that theoretically there are some intermods.

Ironically in all the interference cases I've seen where the problem has been another radio mic, it's been in channel 38, not the supposedly risky channel 70. That said I'd never put a principal character on channel 70 and reserve those mics for chorus duties.

If you're short on channels then consider 2.4GHz or VHF as an option. 2.4Ghz is behaving fine for me, and VHF was (apart from problems with old equipment) up until recently when I retired it all in favour of 2.4GHz. Currently running 20 channels of mics (soon to be 22) which isn't bad for one £75 license fee! I'm seriously considering swapping my primary mics from being the channel 38 ones, to 2.4GHz.