pete10uk Posted September 4, 2011 Share Posted September 4, 2011 Evening all. we have just swapped all our wireless mic stuff to Ch38 equipment. I remember receiving an addition to our current ch69 licence which included ch38. Unfortunately I can't lay my hands on it at the moment. What are the frequencies available to use in ch38. a quick google search seems to suggest anything between 606.500 - 613.500 but I use to a list of specific frequencies to use, as with ch69. Whats best to use? are there best practice frequencies or will any between the above do? Cheers Link to comment Share on other sites More sharing options...
smalljoshua Posted September 4, 2011 Share Posted September 4, 2011 Just got my licence document from JFMG out here, it doesn't state any specific Frequencies for me either. I just use sennheiser's software to calc ones that are intermod free. Josh Link to comment Share on other sites More sharing options...
pete10uk Posted September 4, 2011 Author Share Posted September 4, 2011 Just got my licence document from JFMG out here, it doesn't state any specific Frequencies for me either. I just use sennheiser's software to calc ones that are intermod free. Josh Thanks for the reply. I've always just used the frequencies listed on my ch69 licence. I use sennheiser 300 mics and have often wondered what the easy setup and the frequency banks are actually used for. In my own mind the frequency banks are used to store the frequencies you are licensed for but for the 38 stuff this seems irrelevant as on face value you can use any between 2 points. I'll give the easy setup a look but I would have thought keeping to specific frequencies would help inter mod. Any advice on best uses would be appreciated. Link to comment Share on other sites More sharing options...
chelgrian Posted September 4, 2011 Share Posted September 4, 2011 Whats best to use? are there best practice frequencies or will any between the above do? Unlike the channel 69 license which was for specific frequencies the channel 38 license covers any frequencies within the band. You can't just use any frequencies though for physical reasons as you will end up with intermodulation problems. Your vendor should provide you will a list of recommended frequencies. JFMG did publish a guide which recommended the following 10 frequencies as being usable together http://www.jfmg.co.uk/pages/news/Ch38_proposed.htm 606.600607.500608.150609.150609.950610.550611.250612.300613.150613.500 Link to comment Share on other sites More sharing options...
smalljoshua Posted September 4, 2011 Share Posted September 4, 2011 Have a look at this, I use that for all my freq planning. http://www.sennheiser.co.uk/uk/home_en.nsf/root/spec_wsm Josh Link to comment Share on other sites More sharing options...
pete10uk Posted September 4, 2011 Author Share Posted September 4, 2011 Whats best to use? are there best practice frequencies or will any between the above do? Unlike the channel 69 license which was for specific frequencies the channel 38 license covers any frequencies within the band. You can't just use any frequencies though for physical reasons as you will end up with intermodulation problems. Your vendor should provide you will a list of recommended frequencies. JFMG did publish a guide which recommended the following 10 frequencies as being usable together http://www.jfmg.co.uk/pages/news/Ch38_proposed.htm 606.600607.500608.150609.150609.950610.550611.250612.300613.150613.500 Seems like a good list. I did look on the jfmg site but couldn't find anything. Could probably do with it being made easier to find on their site. Cheers Link to comment Share on other sites More sharing options...
Al M Posted September 5, 2011 Share Posted September 5, 2011 Does your new ch38 kit not have a preset group which uses only channel 38 frequencies? For most brands who have brought out ch38 kit there is at least one, and the frequencies in each preset group will work together without intermodulation. There are no specific frequencies which have to use like there was for Ch69. Link to comment Share on other sites More sharing options...
Floydey Posted September 9, 2011 Share Posted September 9, 2011 Hi I have a dozen JTS radio mics. Originally these were on Ch69. Ten of these have just been converted to Ch38, the other two will be done when I have ascertained if 12 mics can actually be squeezed in this allocation. I have looked at the JFMG frequency plan but unfortunately the JTS transmitters I have only tune up by multiples of 125 khz i.e. 606.500, 606.625 606.750 etc. I have managed to find an on-line frequency calculator at Linky Using this, I can only seem to squeeze in 9 frequencies. I can't see any info regarding Ch38 on the JTS website and even the company who originally supplied the sets are struggling to find any decent information. Is there anyone else having this problem? Link to comment Share on other sites More sharing options...
Al M Posted September 9, 2011 Share Posted September 9, 2011 Even with top of the range kit like Shure UHFR, the manufacturer suggests a maximum of 11 frequencies together in Channel 38, so 9 is probably about right for a JTS system Link to comment Share on other sites More sharing options...
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