Radio mic licence - advice needed.

[Simon Lewis]

PMSE refers to the activity. PMSE users have free access to the 863-865MHz slice of channel 70; can obtain a Shared Licence for 606.5 to 613.5MHz in Channel 38, plus 823-832MHz and 1785-1805MHz; and can apply for a Co-Ordinated Licence in TV channels 21-37 and 39-60.

 

Channel 70 is not site or time specific. The channel 38 (etc.) licence is the one that many people buy and is for one or two years but not site specific and the hirer can let hired out radio equipment be licenced by generating a form for the user. The co-ordinated licence can vary in time from a couple of days to a year and is both unique (you are the only person who should be licenced to operate in that location) and is location specific. The OP is discussing equipment which would require a co-ordinated licence.

 

To be fair to those who have responded, it is generally understood that the spectrum as described above is allocated solely for PMSE use or managed PMSE use alongside TV and that other usage is not permitted. Given that PMSE use requires a licence (apart from the narrow slice of free to use spectrum in channel 70) there aren't any situations where one can tune to these frequencies and use them without a licence. If the replies have been a little forceful, it is because the OP appears to be trying the find a way of words to get around buying a licence and those replying are stating that there simply isn't.

[david.elsbury]

If OP wants to be absolutely above the law, they could rent or buy some license free mics in the 2.4 ghz band such as the line 6, or shure glxd:)

[sandall]

You could always consider VHF. 4 license-free channels & cheap to hire. It might be worth looking for 2nd-hand sets if this could be an annual requirement.

 

Edit - 5 channels in theory but 174.8 tends to produce intermod. with the others.

 

 

[Simon Lewis]

You could always consider VHF.

Out of interest, is there much professional VHF gear available to hire? From a purchase perspective, there doesn't seem to be anything but entry level gear and the really cheap "novelty" radios for £50?

[richard_cooper]

You could always consider VHF.

Out of interest, is there much professional VHF gear available to hire? From a purchase perspective, there doesn't seem to be anything but entry level gear and the really cheap "novelty" radios for £50?

 

I'd don't know any specifics, or if they'll ever be over this side of the pond, but Shure are releasing VHF versions of ULX-D and QLX-D

 

My link

[sandall]

I don't know any specifics, or if they'll ever be over this side of the pond, but Shure are releasing VHF versions of ULX-D and QLX-D

Can't find any info on bandwidth per device. They quote a tuning range of 42MHz (174 - 216), but only the 1st MHz would be license-free over here.

 

Out of interest, is there much professional VHF gear available to hire? From a purchase perspective, there doesn't seem to be anything but entry level gear and the really cheap "novelty" radios for £50?

 

There is still a lot of "proper" stuff being used out there, so I would assume the smaller hire firms still offer it. It presumably also comes up on the 2nd-hand market as places like churches & schools "upgrade" to cheap'n'cheerful Ch.70 stuff.

 

 

[richardash1981]

Don't know about hire options for VHF, but the offerings on *bay indicate that Trantec 3500 / 3.5 series kit (re-tunable in the field) sells pretty promptly when it comes up, but isn't available very often.3500 receivers much more plentiful than transmitters! Audio-Technica VHF (all fixed tuning) come up more often, along with the fixed-frequency Trantecs. Most of the buy-it-now listings are well over the odds compared to auctions if you have the patience, and even more so if you don't mind sourcing replacement power supplies (avoid switch mode ones!).

[sandall]

..... if you don't mind sourcing replacement power supplies (avoid switch mode ones!).

 

Is this from bitter experience or just a feeling that simpler is best? The only switch-mode failure I ever recall was in a brand-new A&H desk (instantly replaced), but have had several Trantec transformers fail over the years. Also, 12v switch-modes are so cheap it's worth keeping a few spares just in case.

[richardash1981]

..... if you don't mind sourcing replacement power supplies (avoid switch mode ones!).

 

Is this from bitter experience or just a feeling that simpler is best? The only switch-mode failure I ever recall was in a brand-new A&H desk (instantly replaced), but have had several Trantec transformers fail over the years. Also, 12v switch-modes are so cheap it's worth keeping a few spares just in case.

I spent some time trying my entire collection of 12V SMPSUs when I got a S3500 receiver with a corroded PSU. My conclusion (from a population mainly of cheap far-eastern ones) was that the double insulated ones caused major interference problems if there wasn't a good quality RF earth via the signal lead / desk, and the earthed output ones caused major interference if there was an earth on the desk, because of ground loops via the PSUs. In both cases the interference produced a mixture of white noise and multiple non-harmonic whistles in the audio output.

 

Separately, I bought a cheap CPC wall-wart for an audio-technica VHF receiver which came without one. This doesn't have high frequency issues, but it does hum if you turn the receiver output level down to feed it into a microphone input. If you turn the output level all the way up and patch to a line input it works UK, but this is then different to all the other receivers.

 

An unregulated linear PSU (from an old home router I think) works just fine on the Trantec, is not earthed so cannot cause a hum loop, but works fine without an earth (e.g. into a double insulated powered speaker).

[sandall]

Looks like I'd better duplicate your experiment & see if I meet the same problems :(