Hotspot setup - being a good neighbor

[ergbert]

Hi,

By way of introduction I just passed my Technician last night, so no call yet, but I've been messing with LMR and GMRS for a while now. So I'm pretty darn green, but I do know enough to be dangerous. I'm building a hotspot, using Repeater Builder's STM32-DVM, attached to a LMR radio. While waiting for my parts to arrive, I'm looking up information on setup, best operating practices, and so on.

I'm in an area with heavy analog coverage, particularly on VHF, but very little digital usage within a 50 mile radius of me. Aside from selecting an appropriate frequency, are there any other ways to make a hotspot less obtrusive in such an area, surrounded by people who don't really like it much?

 

[kv5e]

Hi,

By way of introduction I just passed my Technician last night, so no call yet, but I've been messing with LMR and GMRS for a while now. So I'm pretty darn green, but I do know enough to be dangerous. I'm building a hotspot, using Repeater Builder's STM32-DVM, attached to a LMR radio. While waiting for my parts to arrive, I'm looking up information on setup, best operating practices, and so on.

I'm in an area with heavy analog coverage, particularly on VHF, but very little digital usage within a 50 mile radius of me. Aside from selecting an appropriate frequency, are there any other ways to make a hotspot less obtrusive in such an area, surrounded by people who don't really like it much?

Go to 70cm......lots more room and the band plans are more flexible.

 

[K5MPH]

Congrats on the ham ticket and good luck in the hobby......

 

[nd5y]

Don't use the CW-only, weak signal or satellite subbands:
144.0-144.1
144.1-144.4
145.8-146.0
431.0-433.0
435.0-438.0

Don't use common FM simplex channels like:
146.46-146.58
446.0-446.1

See if your state/regional frequency coordinator mentions hotspots or VoIP simplex nodes in their band plan.

Pick some frequencies that don't appear to be used in your area (that aren't repeater inputs in your area) and scan them for a few weeks with a decent outdoor antenna if possible. Pick some vacant ones. Be prepared to change frequencies if you get complaints.

 

[ergbert]

Don't use the CW-only, weak signal or satellite subbands:
144.0-144.1
144.1-144.4

145.8-146.0
431.0-433.0
435.0-438.0


Or somebody will notice and complain:
https://forums.qrz.com/index.php?threads/dmr-interference-on-435-350.625614/

I had noticed that...there's a similar thread here on RR. Since I am using an actual radio instead of just a sub-watt modem board, the lowest I can go is 1 watt, so I'm trying to go the extra mile to ensure I am not shoving DMR where it doesn't belong.

 

[ergbert]

Ok, day off work so I've been doing a bunch of poking around in radio programming utilities, and looking at or for band plans (they're darn hard to find sometimes!).

Why does it seem that digital simplex nodes aka hotspots, or digital repeaters for that matter, do not seem to use CTCSS/DCS tones? I can set the transciever to use a tone, but I can't seem to set my HT (Radioddity GD77, yeah yeah CCR I know) to use one when programming a digital channel. Seems to me, particularly for hotspot use, tone squelch would be desirable, and keep the hotspot from answering someone who was using analog on the same frequency albeit with a different or absent tone.

The collective knowledge here has an answer for this, I'm sure...but what is it?

 

[N4GIX]

Simply put, digital doesn't "do" sub-audible tones. It doesn't need them! If you configure your MMDVM to be "private" rather than "public", then no radio that isn't programmed to use your unique DMR ID will be able to access it. Period.

In addition, no analog radio will ever be able to access your "hotspot" either. So, no problem!

For that matter, you would be advised to use not much more than a dummy load for an antenna, since you aren't going to be accessing it from very far away normally. You need to knock that 1w signal down to size. There's a reason these hotspots are typically 10mw after all...

 

[ergbert]

Simply put, digital doesn't "do" sub-audible tones. It doesn't need them! If you configure your MMDVM to be "private" rather than "public", then no radio that isn't programmed to use your unique DMR ID will be able to access it. Period.

In addition, no analog radio will ever be able to access your "hotspot" either. So, no problem!

For that matter, you would be advised to use not much more than a dummy load for an antenna, since you aren't going to be accessing it from very far away normally. You need to knock that 1w signal down to size. There's a reason these hotspots are typically 10mw after all...

So, an analog user keying up on the frequency I have my hotspot set to would be treated to a burst of DMR, until the hotspot realized it wasn't talking to a compatible device? This is where I'm confused. It wasn't so much about public vs. private use, as minimizing unneeded emission of objectionable digital signal. Of course, the UHF ham bands around here seem to be very quiet, but still...

As far as the antenna goes, I have one of those Diamond SRH805 plastic bullet looking antennas, that judging by its performance on my HT's, should mitigate the signal output considerably. The whole reason for going with a commercial transciever was better quality of signal, and selectivity as opposed to the single board with an antenna setups, in addition to the whole because I can thing.

 

[N4GIX]

No an analog user wouldn't hear anything. The hotspot is a simplex device. If it receives a valid digital signal it will then send that over the internet to the Brandmeister host you've selected, and that host will then simultaneously send it across the entire network to whichever sites are currently set to receive the selected Talk Group.

After unkeying the hotspot, it will then send whatever comes back from the internet server and transmits it to the user's radio.

Since an analog radio is ignored by the hotspot, the user will never even know it is there.

 

[n9mxq]

Since an analog radio is ignored by the hotspot, the user will never even know it is there.

They darn sure will if it's transmitting.. The DMR Jackhammer is very distinctive..and annoying on an analog radio ;-)

 

[N4GIX]

They darn sure will if it's transmitting.. The DMR Jackhammer is very distinctive..and annoying on an analog radio ;-)

Okay, if by some astronomical miracle they just happen to be in range of the mighty 10 milliwatt transmitter...

...but even so, it would *not* be because they woke it up! :wink:

Why am I thinking now of mountains and molehills?

 

[n9mxq]

My neighbor found mine..dunno how, but he did.. he knew it was me by the CWID..

Asked me about it, and ended up buying a DMR ht.. see him use it once in a while. He's mainly a QRP guy..

Sent from my SM-G950U using Tapatalk

 

[N4GIX]

Well, the CWID is sent in vanilla analog mode...

 

[nanZor]

The proliferation of hot-spots has kind of dimmed my enthusiasm for DMR. Very handy - I use one at work down in the rf dungeon.

That convenience comes at a cost though if you don't have a totally reliable internet connection, chopping up your transmission with lost udp packets etc - especially during community prime-time hours.

Nothing more frustrating to hear what could have been a great signal chopped up by your local ISP overloaded traffic, and dropped udp packets.

Just a heads-up from a hotspot user myself - sometimes during prime time, or if you KNOW your ISP connection is poor, switch back to a radio-repeater mode, and let the repeater do all the error correction and feed it's isp, and not suffer dropped packets from *your* isp, however convenient the hotspot is.

Solicit *honest* reports, sometimes the hotspot/ISP combo does more harm than good.

 

[WX4JCW]

i love my hotspot, im not restricted by a repeater owners rules, i can go to any talkgroup

if you get more than one hotspot though please use different frequencies to prevent looping

 

[N4KVE]

The proliferation of hot-spots has kind of dimmed my enthusiasm for DMR. Very handy - I use one at work down in the rf dungeon.

That convenience comes at a cost though if you don't have a totally reliable internet connection, chopping up your transmission with lost udp packets etc - especially during community prime-time hours.

Nothing more frustrating to hear what could have been a great signal chopped up by your local ISP overloaded traffic, and dropped udp packets.

Just a heads-up from a hotspot user myself - sometimes during prime time, or if you KNOW your ISP connection is poor, switch back to a radio-repeater mode, and let the repeater do all the error correction and feed it's isp, and not suffer dropped packets from *your* isp, however convenient the hotspot is.

Solicit *honest* reports, sometimes the hotspot/ISP combo does more harm than good.

Sadly, this is the downfall of DMR, & why only 1 repeater locally allows them. 2 others do not. We have plenty of repeaters on tall towers here, so we have HT coverage everywhere.

 

[N4GIX]

How does a repeater owner disallow a hot spot, since they don't even talk to a repeater? Just curious... :lol:

 

[N4KVE]

Easy. They tell us. Plus there’s no internet connection to the repeaters. No C-Bridge.

 

[N4GIX]

Easy. They tell us. Plus there’s no internet connection to the repeaters. No C-Bridge.

Ah, I see. Makes me glad not to live there. I was born in Wachula, FL in 1949, but aside from a few years every once in awhile for college in Ft. Myers and later in Gainesville, I've avoided living there like the plague.

I was never happier than when my parent's sold their "retirement home" on South Estero Island and moved to Harlingen, Texas. I told my dad more than once, "Please do not leave me that house, as there's no way I could afford the property taxes!"

Since that repeater has no internet connection, then that make the "no hotspot" rather much of a non-sequitur. There's no way one could use one on that repeater anyway! :roll:

 

[N4KVE]

Guess so. The repeaters are linked, just not on the internet. Cell phone modems, or something. While SE Florida may not be the best, it certainly beats shoveling snow where I grew up in Canada. Plus these past few weeks, it’s actually been warmer up there than here. So I am happy here. Plus I get to see all my relatives over the winter, because they all come here for a few weeks to escape the winter.