How many channels in ch.38?

[Bobbsy]

I have very good reason to beleive that you can get 19 Trantec S5.3 working with out any issues within Channel 38/39. I have them running fine with no issues

 

19 intermod free frequencies that will operate in the channel 38/39 bands of a s5.3 system.

 

The highlighted text implies that you're actually operating mics on Channel 39 rather than just doing the calculations.

 

I hope you've bought and paid for a license for that channel, otherwise it's not a good thing to be bragging about on a forum that JFMG and Ofcom may well read....

 

Bob

[mrg198]

I was interested in only the shared ch.38 licence. I hire kit out to amateur groups doing shows and I often get asked for 12 and up to 14 channels sometimes. Getting the extra 2 channels to 14 is a hassle which I'd like to avoid if possible. I guess the solution may be to offer 12 in the ch.38 band plus keep 2 of my old sets in ch.70 for those cases where someone wants 14.

 

I haven't done the maths though to check you can get 12 in 606-614 and 2 extra in ch.70 without intermod.

[graemeftv]

I thought that channel 39 was available during the change over period without any additional licence required - maybe someone can confirm

 

Also we have been making customers aware when selling the new trantec s5.3 series microphones that

 

You don’t have to use the pre programmed banks of frequencies - you can use any suggested freq list you choose

 

The new s5.3 has a 16 MHz band width - larger than the channel 69 s5.3's! As they cover 2 channels - 38 and 39

 

the marketing material leads you to believe you can get 12 frequencies working together where if you included channel 39 this can be increased and trantec have published 19 intermod free freq as suggested in previous post.

 

As a general rule don’t forget that most belt pack transmitters are 35milli watts rather than the licence max of 50milli watts, then when antenna are under costumes and next to flesh etc the effective output reduces further. Then not all microphones tend to be onstage at the same time. Overall the inter modulation risk reduces.

 

That coupled with how directional your receiver antenna’s are, how much gain in your antenna, head amps, active paddles etc. all effect the issue.

 

As a result this means people can have larger number of radio mics working together than might be recommended and can claim to have good results.

[waster]

What is the plan if you need more channels than you can fit in channel 38? From what I read its just location dependant 39-60?

[cedd]

Channel 38 and 70 are a long way apart. Intermod's will be in quite high order's by then I reckon.

 

There's the other direction to look in - some decent VHF kit. Both myself and another local engineer are still using Sennheiser SK2012's on VHF with very little trouble. I certainly wouldn't discount it as useless spectrum.

[soundspider]

And just on the point of VHF kit - does anyone still make decent diversity VHF radio mics any more? The old Trantec S2000 series are great bits of kit - only ones I can find now are the Kam cheapie ones (which aren't all that bad), but nothing diversity.

 

Cheers,

Alan

[pattonaudio]

I have very good reason to beleive that you can get 19 Trantec S5.3 working with out any issues within Channel 38/39. I have them running fine with no issues

 

19 intermod free frequencies that will operate in the channel 38/39 bands of a s5.3 system.

 

The highlighted text implies that you're actually operating mics on Channel 39 rather than just doing the calculations.

 

I hope you've bought and paid for a license for that channel, otherwise it's not a good thing to be bragging about on a forum that JFMG and Ofcom may well read....

 

Bob

 

 

Yeah we have our licence

[graemeftv]

I agree with the vhf spectrum. I think there could be a small market to just replicate some of the older diverity kit that trantec made, system 2 , beyer ne70, hw international, all one of the same thing. great as true diversity kit unlike the later trantec s3500 that was not true diversity. shame the s2 never had an rf level meter.

[Bobbsy]

Re: VHF kit, if you ever see anything second hand on eBay made by Audio Ltd., snap it up. It was built like a tank, dead reliable and just sits there and works. Even their pre-diversity stuff was fine at VHF--the lower frequency carries through obstructions way better than UHF and I never had a dropout in years of use. Great British made stuff. The units I had were their original RMS2000 models (made for location use so the receivers needed batteries) made in the mid 1980s and, according to the guy I sold them to, they're still going strong. And that's after visits to places like Afghanistan, Bosnia, Somalia and Rwanda with me....

 

Bob

[graemeftv]

lamp ligther comments that the first freq from trantec list of frequencies in channel 38 would spill into the guard band. and that jfmg's suggested 10 intermod free freq are on a firmer footing which I dont doubt. however both start at 606.600mhz

 

channel 38 starts at 606.000

 

trantec suggest their first freq being 606.600

 

jfmg list from website dec 2010

 

606.600

607.500

608.150

609.150

609.950

610.550

611.250

612.300

613.150

613.500

 

jfmg channel 38 info

[starsky]

A digital system will be released to market that operates on 2 Mhz bandwidth steps in the next few months from 470Mhz to 870Mhz in the same unit

[Simon Lewis]

A digital system will be released to market that operates on 2 Mhz bandwidth steps in the next few months from 470Mhz to 870Mhz in the same unit

Are you able to elaborate?

[Lamplighter]

lamp ligther comments that the first freq from trantec list of frequencies in channel 38 would spill into the guard band. and that jfmg's suggested 10 intermod free freq are on a firmer footing which I dont doubt. however both start at 606.600mhz

 

jfmg channel 38 info

To clarify

The chan 38 licence is for 606.500 to 613.500 MHz

The comment about encroaching the guard band is refering to the first frequency in the list mentioned in the preceding post (12) ie 606.500 MHz.

Brian

[AndyL]

To clarify

The chan 38 licence is for 606.500 to 613.500 MHz

The comment about encroaching the guard band is refering to the first frequency in the list mentioned in the preceding post (12) ie 606.500 MHz.

Brian

 

In the UK and Europe TV Channel 38 itself is 606MHz to 614MHz. The UK shared licence permits radio mic (and IEM) operations from 606.500MHz to 613.500MHz, thereby incorporating the guard bands in to the licence so that, as far as I am aware, operation on a carrier frequency of 606.500MHz and or 613.500MHz is permitted.

 

Regarding the use of channel 39 or 40 on a shared licence; this is only permitted at present at locations where channel 38 is not available. If channel 38 is available at your location then in order to use either channel 39 or 40 as well as 38 you need a separate fixed site licence for channel 39 or 40 as well as your shared ch.38 licence. The ch.38 lookup tool at http://www.jfmg.co.uk/JfmgEcom/Wireless/Public/MicrophoneSh600.aspx doesn't actually reflect the true availability of channels 39 & 40 because, under the terms of the shared licence, channels 39 or 40 are only available at locations where channel 38 is not available. If you want to know the real availability, i.e. whether there is a TV transmitter already occupying the channel, you have to log in to the secure part of the site (http://www.jfmg.co.uk/JFMGECOM/Ecom/LoginPage.aspx?ReturnUrl=/JfmgECom/Ecom/Private/CustomerWelcomePage.aspx) and use the UHF mic planning tool. That will show you all the available channels from 21 to 68.

 

Frequency sheets for Sennheiser Evolution G3 Range GB - 606MhHz to 648MHz can be found here:

 

http://www.sennheiser.co.uk/sennheiser/products.nsf/resources/C12573B10069CA4AC125751500044159/$File/ew%20G3-GB_540058_0510_SP9.pdf

 

and for IEM's here:

 

http://www.sennheiser.co.uk/sennheiser/products.nsf/resources/C12573B10069CA4AC12575140083C4C2/$File/ew%20G3-IEM-GB_540059_0510_Sp9.pdf

[paulsparrow]

Download the free Sennheiser SIFMPRO software for frequency sets. 10, 12 at a pinch is the answer I think. You can of course go into 39 & 40 in certain locations.