Amateur (Ham) Radio BS and Callsign Thread!

I'm kinda in similar boat here, and with recent discounts I started considering yeasu 400xdr and icom I'd 5100, but being a noob, not sure if they might be too much of a radios for me.
There is a sale o Icom 2730a $250 or so, which puts it at $100 less than a favorite Kenwood v71a.

Edit. BTW, I already have Mobilinkd 2.2 at home, just didn't have time to hook it up just yet...

 

I'm not super familiar with APRS so please pardon my ignorance, but are you saying that: if I have a full duplex radio (listen to two channels simultaneously) I can use a cell phone as the GPS part of the radio? And still use the other side to scan repeaters/talk simplex to other people?

I have a lot to learn about hamming

 

The TM-V71 is a nice radio and you can run APRS either by using your own TNC or buying the TM-D710 face. But if you never use APRS the Icom gives you all the other radio functions and is a good value.

But radios are like trucks, you can justify each incremental upgrade by saying "It's only xx Dollar more." Eventually you spend $500 instead of $300. Especially for a first radio I would encourage a fella to stick to your budget and get the radio that best meets your criteria at the amount you want to spend. Then use it, find out what you do and don't like or wish it had. There will always be someone willing to buy your old radio and the manufacturers are always willing to take more of your money.

 

Yup. I mentioned the mobilelinkd device. That plugs right into your radio. Then you can connect to it via Bluetooth. There are aprs apps, like the one showed on my tablet. I can message through it, scroll through an area map of hams, or just pull up a data list.

And ask away. That's what everyone is here for.


I have a dual watch radio. So all it does is cut my simplex tx for a split second to send packet data and I can keep talking. I just let the group know ahead of time that it may happen

 

You are perhaps mixing up how things work. All of the typical dual band, dual VFO radios can essentially function as two radios in the same box. That means on one side you can receive and transmit while the other side scans or listens to another station. If you hear traffic on the secondary side you can switch over and transmit without losing the ability to still hear the side you just left.

Some radios go above that and can switch for you when the secondary side needs it. That's when the APRS TNC wants to send a beacon. That is something the FT-8800/FT-8900 can NOT do. It will only transmit on the side you have selected and if the external push-to-talk is activated it will on the channel you select to be main, which results in the voice side getting an earful of modem noise. The TM-V71 when you connect it to Mobilinkd (or any other TNC) will momentarily switch sides to do the APRS stuff and then return you to the other side. There's a menu item that lets you define one side as "data" and so when PTT is active it knows to switch sides. The TM-D710 and FTM-400 do this for you as well for their internal APRS functions.

It's not actually the radio that needs GPS data but the TNC, which means Terminal Node Controller. It's the brains for doing packet radio, e.g. APRS. It needs the location to use, which can be GPS or a value you punch in. The radios themselves don't know anything about packets and GPS. If you have a standalone TNC you can use pretty much any radio for APRS. Cheap handhelds, any mobile, etc.

What you need to ask is "Can a phone be the GPS source for the TNC?" The answer is "maybe." The TNCs in the TM-D710 and FTM-400 can use external GPS sources coming in as NMEA data. That can be such things as a Garmin GPS handheld or puck. Phones don't usually have a way to output location data to a serial port correctly, so you'd need to use APRSdroid and a Mobilinkd, which do know how to do that. The location data is available to apps, which can do some limited things with it. So if you go that way you're better off spending less on the TM-V71 since you'd be bypassing the internal TNC and APRS functions in a TM-D710 for the most part.

I don't know if the IC-2730 can switch transmit sides when an external TNC request it. If it can then APRS on it will be straightforward like the TM-V71. If not then it would be like a FT-8800/FT-8900. Those radios can listen to APRS but you can't let them transmit in the background because they don't know anything about data use.

 

Forgot to mention that APRSdroid and Mobilinkd isn't the only way to do APRS with a phone or tablet. You can tinker and use different programs (using a Windows tablet maybe with APRSISCE/32 for example), keying circuits, VOX and audio signals in & out or a different TNC with a cable to the radio to do APRS with a phone/tablet in other ways. But APRSdroid + Mobilinkd is definitely the easiest.

 

@DaveInDenver I'm going going to have to pick your brain someday about messaging long distance through APRS RF to digipeater to RF. I hit a wall / need to learn more.

 

Yup.

Just said that stuff since ham radio is all about experimenting so the easiest way isn't always the most satisfying. I like to encourage the geekiness in new hams since that's really what it's about. Doesn't have to be of course. But sometimes the challenge of doing something differently is enough by itself.

 

THANK YOU!

This has been super-helpful. I will take all of this into consideration. I don't really want APRS right now, but I'm just thinking of the long list of stuff that is available via ham, I could see myself getting into this next. So if a radio could do it (with help from APRSdroid, etc.) that could tip me over the scale and make me willing to drop the extra few dollars.

So next question: Does anyone know if the IC-2730 can switch transmit sides when an external TNC requests it? I'll be googl'ing... EDIT: No it can't

 

Btw you can use APRS with internet on your phone too for the time being. Via APRS.fi or any of the apps

I use aprsdroid.

 

TM-V71a in my rig too. Looked at various radios and found this one to be full 50W on both 2m & 70cm as well as the ability to run APRS with external devices. Was just under 350 from Ham Radio Outlet delivered to my door.

 

When talking about APRS, you can't forget about the Kenwood d-72a or 74. They are pricey, but the have built in GPS and TNC in a handheld. I was using a d72a with Avmap GPS screen for all my APRS needs. It was awesome, until my Avmap bricked (which was right about the time that Avmap closed all its North American offices) which meant that mine was returned to me un-repaired. I still use my d72a for APRS, I just haven't gotten something for displaying an actual map. I figure a cheap android tablet is in my future. Since the 74 came out, the 72a can be found for a little cheaper, but still not "cheap".

Also, the fact it is a handheld is huge. you can take it hiking, but a APRS beacon you your dog, and be able to track him if needed.

Check out Don Arnold's (W6GPS) channel on youtube. He was the spokesman for AVMAP's APRS unit and is now the spokesman for Kenwood and all things d74. Also does videos on using the raspberryPi for APRS.

 

Good point. APRS has a function called APRS-IS, which is APRS-Internet Service.

http://aprs-is.net

The first thing to know is APRS has repeaters like voice. They work slightly different but the principle is the same, a station talks into the repeater and it re-transmits your signal so that other stations hear it. This is called a digital repeater or we shorten it to digipeater. The biggest difference compared to voice repeaters is you don't have to do anything special with your station for the digipeater to work. It uses the same frequency as the simplex APRS and in fact simplex and repeater traffic can co-exist simultaneously. There is a limit to how many stations can be active in any one place at a time because of all the information flying around, but it's dozens easily, so practically you don't have to worry about it most of the time.

Since each transmission is a short couple of seconds it leaves a lot of empty time to allow other stations to interleave their packets. When a digipeater hears you it reads the packet routing and will act on it. If it reads that the packet needs to be sent back out, it will transmit it on the air with appended routing instructions, if it needs to go to another Internet source (like the APRS gateways to email or SMS) it will send it there or it may do nothing since it reached it's final destination at the repeater.

APRS-IS is a network that allows digipeaters that also have Internet access to talk to each other over very wide areas (globally really). Any Internet application can link to the network and when you run APRS.fi (which is a website that is an interface to APRS-IS) on your phone it probably will be using the wifi or cell phone data directly on the Internet rather than using the RF side with a TNC and radio.

Also realize that most of the time APRSdroid (which knows how to do both Internet and RF) or anything else (Xastir, APRSISCE/32, etc) is probably downloading maps from the Internet. It's important to realize this because when you leave pavement and towns and lose your cell signal you'll need to have cached maps and a RF link configured for APRS to still work. APRS will work no matter if you have Internet or repeaters but without them it's the two radios talking directly to each other and put dots on a blank map.

 

This is very helpful (if a little over my head) can you link me to somewhere that explains APRS so I can use that instead of clogging up this thread (and your time)?

 

You are not clogging anything IMO.

ETA: I'll fess up to probably data dumping more than you're asking but I'm not sure there's an APRS thread to move this discussion to.

The clearinghouse for APRS is of course: http://www.aprs.org

 

AprsDroid offline maps for added refference

https://aprsdroid.org/osm/

 

If you have time, this video explains some APRS things
https://youtu.be/T7hot6_K6e4

 

Thanks for looking that up!
I assumed that it had data port and mode just like v71