Your Questions Answered, June 2019

The summer months are upon us, so that means more outdoor operations activities. I know I have a busy month ahead so I’m planning some fun videos over the next few weeks, stay tune to the end to hear more about them. but first, let’s get into your questions.

APRS is a pretty hot topic on my channel, and I’m planning more videos on the subject, but first, here’s a couple of follow up questions from my recent Advanced APRS features of the Yaesu FTM-400

Starting our with a comment from Bret, he says.

Great video!  Keep up the good work!  Is there an emergency beacon that can be turned on?  I just purchased a 400 to take to the mountains to use in the trials.  I want to learn how to broadcast my position if we find someone who needs emergency help.  Thanks!  Bret C / AC0AE

There is a method to send an APRS position tagged as an emergency packet which will then trip alarms on people’s home stations, but those messages are often ignored due to either misconfiguration of the user radio, or a lack of monitoring for those messages. I think if you are part of an emergency situation, I’d 1) beacon from your fixed location and change your status text indicating an emergency 2) call out on APRS channel via voice alert for nearby stations to respond and 3) try to establish contact on a local repeater.

Next, Sean asks

I am stuck on A band and B band when it comes to the APRS frequency as well as programming frequencies in to A and B band.  Does this mean I can program the A-band with VHF freqs both analog and digital even though A band is for the UHF side?  Please get me straight on this issue I am having.   I guess it’s up to the owner of the radio on how they program the APRS frequency.  Thanks 🙂  73s de WB4UR 🙂

Most people use the B band for APRS and the A band for everything else. The FTM400 has only one digital vocoder, so you need to use the A band for any system Fusion operation and the B band is analog only. There are as many different ways to set up your radio as the day is long, but the way I have my radio channels set up is that the A Band has all my 2 meter and 70cm repeaters that I commonly use and some simplex channels. The B band is the APRS channel as channel one, more 70 cm and infrequently used repeaters, and a full list of simplex frequencies.  I hope this helps.

Next up, 66  echos a common question I receive:

Voice alert would have been a good one to go over.

I’ve had quite a few requests about this feature, so I’ll talk about it a bit. The voice alert allows you to call out on the APRS channel and any capable receiving station will break your audio through the speaker. The purpose of voice alert is that when you see another nearby station pop up on your screen, you can make a quick voice call to them and then change to another frequency. The way the alert works is that you set your radio to transmit a 100 Hz subaudible tone with the transmission. This is used as filter as digipeaters won’t retransmit a transmission with a subaudbile tone, and the radio will filter out the packets without the tone, so you won’t hear the background noise on the APRS channel.

To set the voice alert, go to the APRS menu and select option 32, Voice Alert. Change the alert mode from Normal, which actually means Off, to Tone SQL. Then leave the tone squelch value set to 100 hz. Then when you receive a voice alert message, the radio will beep and pass the audio. You can carry on a quick conversation on the APRS channel to coordinate a frequency change for a longer voice conversation. Please note that this function does use resources on the APRS channel, so please keep those voice conversations short, short enough to move to another frequency.

Speaking of APRS, I received this question from Brian about SMSGTE

Do you have to register with SMS gte or can you do this without registering with them? I might be confusing my own myself

No registration is necessary to use the service. All you do is send a message to SMSGTE and it works automatically. You can register to create an alias, but that isn’t necessary.

I did get a couple of comments about SMSGTE not working properly for a few people. They’d be able to send messages just fine, but couldn’t receive any acknowledgement. This has to do in part with one way I-Gates. Some hams will set up on APRS I-Gate that only listens to the APRS channel and feeds the packets to the APRS internet stream. But it won’t take packets from the stream and transmit them over the airwaves. This halfway approach may be convenient as you can use an old scanner or an SDR dongle as your igate receiver, but it also cripples the utility of the APRS mode. With two properly configured Igates, I could send a message over the air to another station hundreds of miles away, it would travel over RF, to the data stream, and back to RF to the receiving party. With a one way I-Gate, the receiving party may never get the message. So if you are thinking of putting up an igate in your area, please make it a two way I-Gate. I’m planning a video on Igates in the near future, so please watch for that.

I did get a couple questions about the recent Chameleon EMCOMM III base antenna review. David writes:

Interesting but it would have helped my understanding to have a drawing of where this antenna went to and height at both ends and direction of the wire.  Did you use a tuner in this situation?

I probably should have included a diagram of the installation as it can be a little difficult to discern in the video how the antenna is deployed. We went for an inverted L style installation, with the majority of the wire being horizontal and about 30 feet off the ground. The counterpoise was about 52 feet long and it just ran alongside the foundation of the building.

We did use a tuner as the SWR was between 1.5:1 and 3:1 depending on the band and frequency. Almost all end fed antennas do require a tuner of some sort. Most end feds will tune fine if your rig has a built in auto tuner, so you may not need an external tuner with this antenna. Our initial thoughts in using the Heathkit was that since it has tube finals, it would be more forgiving. But we switched to the Icom and it doesn’t have a built-in tuner, we used an external tuner.

That’s it for this month’s questions, please keep them coming. As for topics this month, ARRL Field Day is approaching, and I’ll be active with our local club’s Field Day event. You can look forward to a video on that. I also have a couple of product reviews coming up, including the mystery item that is in this box. It’s summer so you can expect that I will spend a lot less time in the shack and more outdoors.