VK-DMR Network updates - January 2023

 Begin forwarded message:

From: "VK3TE via groups.io" <vk3te=bigpond.com@groups.io>

Subject: Re: [VK-DMR] Changes to the VK-DMR Network

Date: 29 January 2023 at 10:11:55 am AEDT

To: <VK-DMR@groups.io>

Reply-To: VK-DMR@groups.io

Good Morning All

For Hotspots this will have NO Impact to you as you set your TG’s that you want to listen to.

The Link from the Repeater Server to the Hotspot server to pass the TG’s will NOT change

So what ever is on the IPSC2 Repeater server will still pass the TG’s to the Hotspot Server

 

The Phase 2 all you will have to do is move the TG 380x to TS 1 Now and the same to reprogram your Radio for TG 380x to now use TS 1 (Time Slot 1)

 

Now for your Promiscuous Mode, we keep telling you that your Hotspot could hear another TG, and with your Radio is programmed to Promiscuous Mode it will jump to this TG, and if your Hotspot hears another different TG it will jump to this TG and your radio will follow and you do not know what you could be listening too, this happens a lot when listening to the TG 5 Broadcasts, and you then try to talk back to the person and you are now on a different TG.

 

This has been reported many times and even watching the VK-DMR IPSC2 Hotspot and Repeater Dashboards many of these promiscuous mode users are on the wrong TG when trying to talk back

 

As this is your choice we keep telling Amateurs that Promiscuous mode is not a good practice

 

You should be setting the TG for RX and TX for each channel you have programmed to your Radio, as the Hotspot just listens to what it is set to, and will follow what your Radio is sending to your Hotspot.

 

Anyway the Phase 2 of Changers will be coming to make it easier for all to use moving forward and the TG 8 for each Region will be removed and replaced with a New Set of Fixed TG’s and the TG 10008 to 90008 that is TG 8/1 to 8/9 will be replaced with a all New Set of TG’s you will need to check on the VK-DMR Network Web Site at https://vkdmr.com/

 

Peter Brennan

VK3TE & VK4SPB

AN fittings and sizing

 this is good site for AN fittings and their sizing measurements,

AN tube fittings common on oil & transmission coolers for cars

An Fitting Size Guide (hardin-marine.com)

Australia Day 26th January, 2023 - AX prefix

 AX prefix can be used instead of VK prefix today.

Australia Day represents 26th January, 1949, also simultaneously celebrated  in India as Republic Day,

unlike the Australian media pushing 26th January as the day the First Fleet arrived in Australia, which is incorrect. 

2metre enhanced propagation 26th January, 2023

 vkspotter showing a few path openings this morning , as  we had some low lying fog here in Sydney and others reported fog down Wollongong area.  I found 146.750 VK2RFS was open at s5, normally not accessible from here. Heard VK2BHO and VK2STG chatting. 

Noted that VK2RFS Mt.Mumbulla 146.750 is linked to VK2RWP Cooma 146.825 and VK3RDH Mt.Delegate 146.625 Mhz. That is handy to know when I next mobile down that way.

Interesting WSPR report 25th January, 2023

 I never realised there was a 40MHz  amateur band. Very interesting.

from vkspotter.com :

• 25 Jan22:2442 minutes ago

  WM2XCC in DM1340.680000 WSPR -23

  Spotter: ZL1RS in RF64VS @52° 10471.6 Km

Doing a Google on 40.680 Mhz WSPR, I find G3XBM talking about 40.680MHz- 8metre band.

Roger G3XBM's (Mainly) Amateur Radio Blog: 8m QRP FT8 (first) on 40.680 MHz TX and RX (g3xbm-qrp.blogspot.com)

Wayne Knowles, ZL2BKC silent key

 Wayne Knowles ZL2BKC, creator of the ZL PLL boards for microwave and weak signal enthusiasts, became silent key on 30th December, 2022.

RFI/EMI from Inverter type Air Conditioners

 We replaced our 20 yr old Daiken R/C A/C for a new 18kW Daiken 'Inverter' type R/C A/C a year ago, I discovered this new A/C is very noisy on HF bands, particularly across 7 MHz and 18 MHz, the new Inverter type A/C are more efficient at heating and cooling,  however, the tradeoff is that the external compressor  unit is radiating RFI (Radio Frequency Interference) and EMI from either the Inverter Power supply or the DC fans.   It's bad enough dealing with RFI from damned solar panel Inverters, but at least dealing with  a RFI source in my own place is easier than solar panel Inverters on someone else's roof.

The main times we use this A/C is in middle of winter and summer. At first I did not suspect the RFI was coming from the A/C, as if I switched it on or off, I would not see any change to the RFI at the HF receiver, as I discovered after many attempts, that there was a delay of a few minutes, i.e you switch on, the compressor unit  it does not come on instantly and when you switch off, the compressor does not stop instantly. It took a while to catch on that it was indeed the A/C unit. Then I did various tests to determine from which end of the system, the internal blower unit or the external compressor unit was creating the RFI, it  was pretty easy to determine it was coming from the external compressor unit. I remembered the A/C installer saying these are all Inverter type systems. That triggered my memory about friends working in commercial radio comms saying they use these Inverter A/C systems out on remote comms sites to cool  the equipment in the comms sheds and that they create RFI. Now, I at least knew that the external compressor unit looks like the place where the Inverter Supply is located, or whatever is generating RFI hash is in the external unit.

I did a search on Google to see if anyone else discussing this type of issue and to see if anyone had some good ideas to fix it. For myself, I presuming I need to make use of some ferrite cores in the right place to knock down the interference. Found someone discussing his issue with his Fujitsu Inverter A/C system, so definitely a common issue. Plus some videos and a white paper on the topic. The Mitigation video gives the detailed technical understanding the issue and solutions.

Fujitsu inverter air conditioner radio interference - Fixya

Application_guide_aspects_of_electromagnetic_compatibility.pdf (abb.com)

Ruud Air Conditioner (HVAC) Radio Interference - YouTube

Mitigating Residential Heating, Ventilation and Air Conditioning (HVAC) RFI - YouTube

DMR status updates as of 3rd January 2023

Status update on changes for VK-DMR and Brand Meister networks  for VK (Australia) region.

Using DMR – VK DMR this is link to VK-DMR Supported TalkGroup listing.

 Note : VK-DMR is still gatewayed to Brandmeister equivalent TG's

VK-DMR  TG's 3801, 3802, 3803, 3804, 3805 & 3807 all on TS2  gateway respectively to

Brandmeister TG's 5051, 5052, 5053, 5054, 5055 & 5057 as respective State TG assignments

IPSC2 Dashboard Index (vkdmr.com)  VK-DMR Repeater dashboard, currently 57 repeaters connected.

IPSC2 Dashboard Index (vkdmr.com) VK-DMR Hotspot dashboard, currently 268 hotspots connected.

Note: VK-DMR now has some gateways into the Fusion Repeater network.

Repeaters | BrandMeister Brandmeister Repeater dashboard, currently only 11 licensed repeaters in VK, being VK2RAY, VK2RCM, VK3RAH, VK3RBA, VK3RHD, VK3RSV, VK3RUT, VK4RDB, VK6RDM, VK6RLM &  VK7RCR

Hotspots | BrandMeister Brandmeister Hotspots dashboard, currently 252 hotspots connected.

LastHeard | BrandMeister Brandmeister dashboard  "Last Heard" list of user activity.

BrandMeister Talkgroup List - pistar.uk this provides the full list of Brandmeister TG's worldwide, for VK refer to 505x and 505xx TG's

That was interesting comparing VK-DMR versus Brandmeister devices in VK (Australia)

57 x VK-DMR repeaters, compared to 11x Brandmeister Repeaters, 

whereas hotspots is pretty similiar with 268 on VK-DMR compared to 252 on Brandmeister.

Keeping in mind the structure and usage is quite different between VK-DMR and Brandmeister  networks. Each network serves a different purpose, don't try and compare one as being better than the other.

VK-DMR is repeater oriented, linking groups of repeaters in various combinations, but with no PTP TG's, whereas Brandmeister is not repeater focused, but has individual repeaters, but primarily is supportive of PTP connections and multi-mode gateways, including digital to analogue.

Digital mode hotspots and bad choice of operating frequency

 I was having a look at the VK-DMR and Brandmeister network dashboards today, seeing what new repeaters are active and what hotspots are running to gauge usage on DMR (as it seems rather quiet lately) and I noticed again, that there are still plenty of STUPID people running their digital hotspots on the most inappropriate frequencies, I have trouble trying to fathom how people with "supposedly" technical background and license (ham radio license) can make such stupid blunders, with 20MHz bandwidth to play with on the 70cm band, that they can't find a simplex without interferring with other services, especially the amateur satellite segment on 70cm, why would someone setup their hotspot in the amateur satellite segment when there are lots of amateur satellites constantly circling the globe operating across many frequencies ? People can't seem to grasp that you don't need lots of watts to work a satellite travelling overhead. That's why you can work ISS with a small handheld. Your little hotspot running milliwatts can interfere with amateur satellites passing overhead.

Likewise, why would someone setup their hotspot on the same frequency as the input of a analogue voice rptr that's less than 100km away ? Same for the output frequency.  The hotspot may only run milliwatts, but given some enhanced propagation, that tiny signal can go a long way.  I run three hotspots, for P25, VK-DMR and BM and I try to run them with as minimal impact on each other and maximum isolation between each hotspot and other services, i.e. power output turned down and use internal antennas, I was surprised how far away I can hear my hotspots when out walking with my P25 and DMR handhelds, a couple milliwatts, cct bd antenna and located downstairs in the garage and I can hear them almost a kilometre away. Weak signal experimenters will agree, small signals can go a long way under the right conditions.

If you see a friend operating a hotspot on an inappropriate frequency, can you politely ask them to think about a more appropriate simplex. Also if you running a low pwr hotspot you don't need a repeater frequency pair. Repeater frequency pairs are for high powered repeaters providing a large coverage area and as such, are licensed as repeaters. And if you running a hotspot whilst mobile all over the countryside, the choice of frequency for your hotspot is more important it needs to be on a simplex frequency, not on the allocated voice repeater allocations.

APRS and some big trucks

 I often looking at APRS map to see what vehicles or balloon experiments are active on APRS, or following friends who are travelling and using APRS, but also spotting a few regulars, these are truck drivers who I see traversing big distances for their daily work. These are VK2XSB and VK2LPC. 

Both use DMR and other modes. I have heard Ian VK2XB call on DMR, but not for a while now. At the times when I did hear Ian calling, I was too busy doing work at my desk to answer him.  I used to work Ian occasionally on our local 2metre rptr when he driving petrol tankers in Sydney many years ago. I think from seeing his APRS path, he might be doing grain haulage and other freight. In recent months I been trying to pay more attention to checking where he is on APRS and listen for him on DMR.

I passed Ian a few months back near Goulburn when I was mobile from Sydney to Albury, I wasn't paying attention to the APRS heard list at time I passed him, I didnt realise until an hour or so later, otherwise I would have flagged him down, or got his attention somehow. 

Similar thing happened earlier last year, we had stopped in at Young, then headed south to Junee and  VK2LPC-14 was returning home, again I wasn't regularly checking APRS Heard list and I think I passed him as he heading home.

Google Maps APRS for VK2XB mobile

Google Maps APRS for VK2LPC-14 mobile