PMR Idiots guide

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PMR Idiots guide

Postby Sid » Thu Sep 20, 2018 9:13 pm

Apologies if these appear daft questions.
I've tried google, but rather than simple explanations, they seem to go straight into the tech stuff - leaving me still confused.

Ok,

I understand your basic pmr - was 8 channels for years and now changed to 16. Analogue and unlicenced.

1. dPMR - is this just simply an unlicensed digital version of analogue PMR, but obviously needing digital radios both ends to tx / rx?

2. DMR - is this just yet another unlicensed version of dPMR? That being the case, when I looked up the frequencies, they are the same as 1-16 on analogue PMR?? - so how does that work?? Does it just tx / rx on the exact same frequencies, but a digital version of? - I don't get it.

Sry if all this sounds daft, but sometimes I just need a really simple child like explanation......... :biggrin:

All help appreciated........ :thumbup:
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Re: PMR Idiots guide

Postby G4RMT » Fri Sep 21, 2018 7:45 am

Yep - in essence that's what the current state of play is - it got a bit confusing when the extra bit of bandwidth was allocated and people assumed this would be digital, or others assumed extra analogue - OFCOMs current statement is this.
Background
Ofcom has worked with colleagues in Europe to, initially, identify spectrum for the Analogue PMR446 service (446.0 to 446.2 MHz) and, latterly, identify spectrum for the UK’s Digital PMR446 service (446.0 to 446.2 MHz).
The Analogue PMR446 service is harmonised throughout Europe. This means that Analogue PMR446 compliant equipment bought in the UK may be used on a licence-exempt basis within any European country.
The Digital PMR446 service is not harmonised throughout Europe. Please note that UK Digital PMR446 compliant equipment may not therefore be used on a licence-exempt basis within all European countries. Likewise, Digital PMR446 equipment that is licence-exempt compliant within other European countries may not necessarily meet the UK’s licence exemption operation requirements.
Please note that Analogue and Digital PMR446 equipment usage within the UK is limited to mobile-only, low-power (i.e. 0.5W ERP1 maximum), short-range, simplex, two-way, peer-to- peer use. Analogue PMR446 and Digital PMR446 allow speech and / or tones. Additionally, Digital PMR446 facilitates the transmission of data, and has an automatic transmission timeout of 180 seconds.
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Re: PMR Idiots guide

Postby m0lsx » Fri Sep 21, 2018 11:27 am

Licence free 446 MHz PMR, is just variation of PMR.

The cheapest licenced PMR is light simple.
https://ukradioscanning.com/viewtopic.php?f=8&t=8

This licence authorises the use of hand-portable or mobile radio equipment anywhere within the UK. Base station use is not permitted. Licensees have access to fifteen frequencies spread across four Business Radio frequency bands and must self-coordinate with other Simple UK Light licensees. The licence fee is £75 for five years.


The above licence covers as many radios & users across the UK as you want, so companies like Tesco's etcpay the same as fred Boggs builders with two or three handhelds.

There is also a site version of the above.
http://static.ofcom.org.uk/static/businessradio/BusinessRadioSimpleSite.pdf

The above licence covers one sit, but allows base radio use.

Then there are the operators who have a personal or shared frequency either via handhelds, mobiles or base radios & sometimes with a repeater.
PMR licences can be very expensive.
Buy a database from Kimmy JS19 via http://ukscanningdirectory.co.uk/
Or do Google search of this forum via http://www.google.com/cse/home?cx=partner-pub-6291336405621919:2662881632
73 De Alan (M0LSX.)
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Re: PMR Idiots guide

Postby Sid » Fri Sep 21, 2018 9:24 pm

Thanks for the info guys.

So, just to clarify question 2, DMR446 is also unlicensed?
That being the case, is there any advantage using it peer to peer over dPMR446?

Thanks again.
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Re: PMR Idiots guide

Postby m0lsx » Fri Sep 21, 2018 10:12 pm

Sid wrote: So, just to clarify question 2, DMR446 is also unlicensed?
That being the case, is there any advantage using it peer to peer over dPMR446?.


PMR 446 is licence free, providing the radio in use meets the legal requirements.
And DMR & dPMR are simply different ways of cutting a single 12.5 khz signal into two 6.25khz slots.
The main difference between the two is when using repeaters, as the equipment for a DMR repeater is a lot simpler & thus cheaper to build. But repeaters are not legal on PMR 446 so no real advantages exist on 446.
Buy a database from Kimmy JS19 via http://ukscanningdirectory.co.uk/
Or do Google search of this forum via http://www.google.com/cse/home?cx=partner-pub-6291336405621919:2662881632
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Re: PMR Idiots guide

Postby G4RMT » Fri Sep 21, 2018 10:39 pm

dPMR offers two channels in the space of one traditional one - so there are more channels, but of course DMR does the same thing but using time slots. As they are so short range/low power, I don't think there's really much advantage of one vs the other.
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Re: PMR Idiots guide

Postby Sid » Sun Sep 23, 2018 12:05 pm

Thanks G4
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