The DV4 Mini is a USB stick with an antenna on the end, made by Helitron. These were the first hotspots for DMR and were quite popular however as more better quality hotspots were launched, their popularity reduced as the manufacturer took some time to release software and firmware updates to resolve the audio quality issues. They are still in use as users have now done the relevant updates.
They come in either a 70cm or 2m stick (antenna sold separately). Prices between £105 (70cm) and £120 (2m) plus around £10 for an antenna.
Both ML&S and Nevada Radio are currently selling these units for around the same price but none seem to have any stock but there are a few for sale on eBay.
More info including links to the software and setup details via the ML&S website – https://www.hamradio.co.uk/digital-modes-helitron-pc-737.php
With the advent of new IPSC2 servers now beginning to be deployed on DMR+, selecting these servers may not be quite so obvious. The following screenshot hopefully will point you in the right direction
In the Expert Settings tab, the radio button marked ‘IPSC’ must be selected. The associated dropdown list will then show you the relevant IPSC2 servers. In the UK it is recommended that you use the ‘SC: IPSC2-PhoenixF’ server.
Please note: You must have the latest version of the control panel installed to take advantage of these new server settings. At the time of writing, the latest version can be downloaded from http://www.dv4mini.de/edownload.html