turn your smartphone into a P25 or DMR HT ?

Well, You can certainly do some neat tricks with SDR’s nowadays, clever things like making your Raspberry PI transmit AM/FM/SSB and the (slightly pricey) but very interesting HackRF board. I see Fenton Dynamics have been busy lately, they’ve rebranded now from BriCom, and i completely missed them first time around,   Anyway, this device, which Read More

Unencrypted TETRA decode with a £6 RTL dongle.

There seems to be some interest in attemptimg to decode unencrypted TETRA witha a £6 RTL dongle, I will post my own how to perhaps later on when i get time, but all i did was read and do what it says here, and you don’t need me to re-tell Read More

North America Mototrbo CPS 12 build 642 bug.

Motorola released a caveat for North American users of CPS_12 build 642.. Motorola issued a ‘Field service bulletin’ because there is a serious issue some users are experiencing where after writing back to the radio using CPS 12 build 642 you lose ability to PTT. not good. It concerns subscriber Read More

Decoding DMR / P25 with the RTL SDR – an update

Setting up  SDR# (or SDRsharp) for use with an RTL dongle is the cheapest way of listening to most digital voice modes on the VHF and UHF bands, and you don’t need to know talkgroups, colour codes, slots or anything, so it’s much easier than any other method, other than forking Read More

The Hitchikers Guide to MotoTRBO CPS

To Quote Zaphod Beeblebrox in ” The Hitchikers Guide to The Galaxy  ” (like i need to put a link to it’s Wikipedia entry) ” It’s the weird colour scheme that freaks me. Every time you try to operate one of these weird black controls, which are labelled in black Read More

How to update your contact list (Motorola)

It seems there is a little bit of confusion surrounding callsigns not being displayed in the radio’s screen.. here’s a quick ‘how to’ that may help. As for callsigns on the various monitoring websites, don’t worry too much about that for now, because DMR-MARC is doing some big changes to Read More

DM4600 audio out – the missing feature..

The DM4600 radios are very good indeed – they do a lot of things and perform well, but here’s one thing that bugs a lot of people … where is the audio out jack ? Well, of  course, there isn’t one, sorry about that.  remember these are not designed for Read More

RSSI, what the hell is that!

I did consider the title ‘where have my μV gone’ but hey here we are. If you are rich/lucky enough to have an Impres microphone for your shiny new Motorola DM4600 or have a DP3600/4600 etc you may have played with the RSSI function. Received signal strength indicator, an S Read More

An audio pre-amp for wired headset use with the Motorola DM4000 series. by ‘Mot Orious’

This is a very useful article penned by Mot Orious  here at GB7MB – i only posted it  ! The circuit presented below is a simple op-amp based pre-amp to provide the necessary gain to enable a two terminal electret microphone to be used with the rear microphone input on Read More

A USB programming lead for the Motorola DM4000 series of mobile transceivers. by ‘Mot Orious’

This is another very useful article penned by Mr. Mot Orious  here at GB7MB – i only posted it. The USB programming lead for the DM4000 series is an expensive item if bought from Motorola. However construction of a home made version is not complex. You will need 1. An Read More