TK-862G Transmissions Not Going Through

[kenwoodgeek]

So, to make a long story short, yesterday on the school bus ride home my bus driver gave me permission to speak to her from my radio today since she had a charter. The plan was for her to call me at 7:30 this morning.

I had my radio on all ready to go. Her transmission came through as clear as can be, as she asked me if I had my ears on. I pressed the transmit button, and the DTMF tones I just programmed into it sounded, and I replied. I waited a few seconds with no reply, so I tried again, no reply. At this point it was obvious she couldn't hear me for whatever reason. Knowing there were several other drivers out today, I did a standard radio check as well to see if anyone could hear me, and no reply at all.

So, I took my radio outside, plugged it all in, and put the antenna on the roof of our car hoping to get my signal out, still no luck. I came back in and reprogrammed the radio. I removed the DTMF tones and also tried adding the DPL tones I obtained from the database, but still nothing. Really disappointing. Here's a video of me trying to contact her, if it helps at all:

https://www.youtube.com/watch?v=Dg5vwcM-Z6A

So, here's what I know about the company's radios. They operate on 461.8875 MHz, and they are mostly Kenwood TK-8180s and NX-800s. I do not believe the system is trunked, but I can't 100% verify that. Does anyone know how I can fix this? Is it a compatibility issue between the 862 and the 8180s?

Thanks in advance!

 

[kenwoodgeek]

I have an update to share. Hopefully someone out there will be able to help.

I talked to my bus driver this afternoon, and we talked about Saturday. I told her that I had heard her call me, but she didn't reply. She told me that after she called me, she thinks she might have possibly heard me calling her, and if she did it was very quiet, which makes me think of a new possibility.

I'm wondering if my TK-862G is not transmitting loud enough. I've heard this before on at least one of the company's radios, but I didn't think it would be a problem with my radio. The transmission came through loud and clear on my scanner, but I'm not sure if it's the same story with the bus radio.

If anyone has any information to offer, please do. My driver says she's going out on another activity charter one of these days in the evening, so we can try again. This time I want to have the radio working, so I'm going to mess around with the programming and do some tests and see if I can track down the problem. In the meantime, though, as I said, any help, advice, or suggestions would be greatly appreciated!

 

[cmdrwill]

I suspect you did not have your radio programed correctly. The bus driver's radio is on a repeater.

 

[kenwoodgeek]

Okay, I see. How would I go about getting on the repeater? Would it be a different frequency?

 

[mmckenna]

NX-800's are UHF analog and NXDN digital.
TK-8180's are UHF analog only.
Both will do LTR (Logic Trunked Radio).

I suspect since you can clearly hear her that it isn't LTR, but just plain old conventional analog.
I'd suspect that the QT/DQT setting is wrong.
or,
They are using a repeater and your radio is set to simplex.

It sounds like there is a repeater hang time at the end of her transmission.
You'd need to make sure you are TXing on the repeater input and RXing on the repeater output.
You also need to be sure you are using the right tones.

Should be an easy fix if you can get the right info.

Also:
Be cautious. I'm not being "radio police" here, just making sure you understand. If you are transmitting, you require either a license from the country you live in, or you need written Memorandum of Understanding with the person/agency that does hold the license. Transmitting without a license can get you in some trouble, but I doubt it'll be an issue unless someone complains.

Good luck on getting this sorted out. I'm happy to see younger people experimenting in radio. It can lead to a life long career.

 

[mmckenna]

Okay, I see. How would I go about getting on the repeater? Would it be a different frequency?

Yes. The repeater will have an input frequency and an output frequency. It sounds like you are already receiving on the repeater output frequency.
On UHF, it's very common to find that the repeater input frequency is up exactly 5 megahertz.
Try programming your radio so you transmit on whatever the RX frequency is + 5MHz. You'll also need to make sure you are transmitting the correct PL or DPL tone to trigger the repeater.

Added in edit:
I see in your original post where you said they are on 461.8875MHz. Use that for your receive frequency. Set your transmit frequency to 466.8875MHz.

 

[mmckenna]

Oh, and make sure you have your channel set to Narrow. The radio you have is capable of wide band and narrow band emissions. Wide band is no longer permitted by the FCC on most commercial frequencies in the VHF High and UHF bands. The radios in the busses should all be set to narrow band. While transmitting wide might work, it'll likely sound like crap on their radios.

 

[kenwoodgeek]

Thank you so much for those replies.

First, thank you for the warning. I knew you needed a license to have your own frequency, for ham, and for GMRS, but I didn't know I would need that for talking on a frequency that's alright licensed out because I had permission, but I don't think it will be an issue, since there's pretty much no one else on when my driver lets me, and the company is very friendly to let me talk on their radios, but like I said, thank you for the warning. I am, however, looking to get my ham license sometime soon here.

What you are saying makes sense, and now after reading all that information you gave me, I can see I already have something wrong. I did have the channel set to wide transmitting, so I will be sure to set that to narrow. That may have been why my driver said she thought she heard me, but it was very very quiet. I will also add the tone that I obtained from the database and try raising the transmit frequency 5 MHz.

I have one question, though. When I listen to the buses on the scanner, I hear everyone talking on the 461.8875. If I was to transmit on 466.8875, does that get sent to the repeater and get converted into 461.8875?

Thanks!

 

[mmckenna]

Thank you so much for those replies.

First, thank you for the warning. I knew you needed a license to have your own frequency, for ham, and for GMRS, but I didn't know I would need that for talking on a frequency that's alright licensed out because I had permission, but I don't think it will be an issue, since there's pretty much no one else on when my driver lets me, and the company is very friendly to let me talk on their radios, but like I said, thank you for the warning. I am, however, looking to get my ham license sometime soon here.

Not a problem. A ham license won't cover you here, it's only good on the ham frequencies. If you got the OK from the bus folks, you're probably not going to have any issues. The FCC licensing rules can be confusing and hard to understand.
Thanks for taking that part of the message as it was intended, just a friendly reminder. I'd encourage you to get your amateur license. It's a great way to learn and really opens up a lot of opportunities. I've been licensed since the early 1990's, and the experience I gained led me into telecommunications and a life long career.

What you are saying makes sense, and now after reading all that information you gave me, I can see I already have something wrong. I did have the channel set to wide transmitting, so I will be sure to set that to narrow. That may have been why my driver said she thought she heard me, but it was very very quiet. I will also add the tone that I obtained from the database and try raising the transmit frequency 5 MHz.

The wide/narrow thing would make you sound really loud to a narrow banded radio, so unlikely that's the cause, but it's good to set it right.
The FCC forced most commercial radio users in the VHF High and UHF bands to go to narrow bandwidth as of January 01, 2013.
The database is probably a good source of information. If you accessed the FCC database and pulled up their license, it'll usually show you what frequencies they are licensed for, but won't tell you what tones they use.

I have one question, though. When I listen to the buses on the scanner, I hear everyone talking on the 461.8875. If I was to transmit on 466.8875, does that get sent to the repeater and get converted into 461.8875?

Thanks!

Exactly. The repeater receives on one frequency and retransmits the audio simultaneously on a second frequency. This offset is used because if it was trying to receive and transmit at the same time on the same frequency, it wouldn't be able to hear anything. Offsetting the frequencies allow the receiver to still hear the mobiles and retransmit the signal at a much higher power.

 

[kenwoodgeek]

Yes, ham radio seems like a fun hobby to me. I'd like to get my technician license as soon as possible, but I heard you have to buy a lot of materials for the class. Still, I'm up for it. I always hear recorded messages play over my local amateur repeaters explaining about upcoming meetings in my town that are open to the public, so maybe I'll have to go to one of those sometime.

Thank you for that information as well. I actually just used the RadioReference database and pulled up the school bus frequencies in my county. I was able to conclude that the frequency uses a 051 DPL tone. After that, I changed the transmit to 5 MHz up like you said.

Since no one is there at night, I did two quick transmit tests. I held the transmit button on the radio for about two seconds, and then released it. After I released it, the LED went to green for about a second with a little noise, just how my driver's TK-8180 responds, and then it went out, so I assume I successfully hit the repeater.

One question I have, though, is why didn't my Uniden scanner pick it up the second time? The first time I transmitted, the scanner made some static noise after I released the transmit button, but the second time, the scanner did absolutely nothing.

One more question, is it still possible to use the DTMF tones on this kind of operation? I'd like to keep them on, but that's just a personal preference.

 

[mmckenna]

Yes, ham radio seems like a fun hobby to me. I'd like to get my technician license as soon as possible, but I heard you have to buy a lot of materials for the class. Still, I'm up for it. I always hear recorded messages play over my local amateur repeaters explaining about upcoming meetings in my town that are open to the public, so maybe I'll have to go to one of those sometime.

There are plenty of free study tests on the internet. Just fine one and start practicing. Check in with your local amateur radio club and talk to them. If they are any good, they'll quickly take you under their wing and start mentoring you. Usually ham clubs like to find new members. Shouldn't cost anything to study. The test is actually free, but the people who administer the tests are permitted to recover costs for postage, etc. Should only be a few bucks.

Thank you for that information as well. I actually just used the RadioReference database and pulled up the school bus frequencies in my county. I was able to conclude that the frequency uses a 051 DPL tone. After that, I changed the transmit to 5 MHz up like you said.

Since no one is there at night, I did two quick transmit tests. I held the transmit button on the radio for about two seconds, and then released it. After I released it, the LED went to green for about a second with a little noise, just how my driver's TK-8180 responds, and then it went out, so I assume I successfully hit the repeater.

That sounds right. When you key up the repeater it will retransmit your signal. When you stop transmitting the repeater says keyed up for a short period of time. This does two things, it lets you know you reached the repeater, and it keeps the system keyed up a bit so if someone responds quickly it helps reduce the system keying, unkeying, keying, etc. Used to be in the old days the relays that did this would fail, reducing constant cycling helped extend their lifespan. Now, that isn't necessary, but it's helpful to know you've reached the machine.

One question I have, though, is why didn't my Uniden scanner pick it up the second time? The first time I transmitted, the scanner made some static noise after I released the transmit button, but the second time, the scanner did absolutely nothing.

Could be a couple of reasons:
When you transmit in close proximity to another receiver, the transmit signal can completely overwhelm the receiver with RF energy. This is called "desense". Even though you were transmitting on 466MHz, and your scanner was listening on 461MHz, the overwhelming amount of RF energy will deafen the receiver. Fairly normal for this to happen. The way to reduce it is to separate the antennas as far as possible.
Could be that you are right on the fringe of coverage. The low signal from the repeater and the desense probably is wiping things out.

One more question, is it still possible to use the DTMF tones on this kind of operation? I'd like to keep them on, but that's just a personal preference.

That is really up to whoever runs the repeater. If the other radios use it, then it's probably safe, but there may be a specified number that individual buses have. Often the DTMF tones are used as a way to identify individual radios.
The risk is that some repeaters are controlled by DTMF tones. Sending the wrong ones could conceivably trigger the repeater to do something they don't want you to.
It's best to either leave them off, or find out exactly what digits you are permitted to send.

 

[mmckenna]

Yes, ham radio seems like a fun hobby to me. I'd like to get my technician license as soon as possible, but I heard you have to buy a lot of materials for the class. Still, I'm up for it. I always hear recorded messages play over my local amateur repeaters explaining about upcoming meetings in my town that are open to the public, so maybe I'll have to go to one of those sometime.

Here are some practice tests:
ARRL Exam Review for Ham Radio™

The first step is to get your Technician license. Master that first.

Here are the question pools:
Question Pools

It's important to not just memorize answers, but actually learn the subject. This is where your local amateur radio club can help you.

Some more info on getting your license:
Getting Licensed

Find a test near you:
Find an Amateur Radio License Class in Your Area

 

[kenwoodgeek]

Thank you for that advice and the links! I didn't know it was that cheap, and I will defiantly start looking into those and taking some practice tests.

That's very interesting how the system works, and that's what I've noticed through listening to the drivers talk. If they respond quick enough to each other, the LED on my radio stays lit without ending the transmission, which I think is very convenient.

And yeah, I figured the scanner was a bit too close, but I wasn't fully sure. I still have a desktop microphone, so I was sitting on the floor with the scanner close. I ordered a Kenwood KMC-27 handheld mike to replace the KMC-9C desktop mike that I have, so I'm excited to have a bit more freedom to move around when I talk, haha.

And that's good to know. Thanks for letting me know. The other buses don't use DTMF tones at all, which is why I wanted to use them kind of for identification purposes when I do have permission to transmit. Either way, I certainly don't want to mess up the repeater's operation, so I will stay away from those. I know my TK-862G has 2-tone, though, so maybe in the future I will program in a 1-second beep or something before I talk.

I will let you know when I try it this week to talk to my driver to tell you how it went. I'm signing off for the night, but thank you for all your advice today, you've been a huge help.

 

[mmckenna]

Glad I could help.
I had a lot of help when I was younger, loaned radios, scavenged parts, home built antennas, etc. I started off with a hand held scanner, Bearcat 100, one of the first hand held programmables. I think it held a total of 16 channels. After that I started messing around with an old CB. Talked to a friend about 1/2 a mile away in the afternoons. I started studying for my amateur license, then had to stop due to school work. After I graduated from high school, I got my first license. Scraped and saved and bought my first radio.

Now I've got a full time job in Telecommunications, 3 engineers/analysts that I manage, several radio systems I'm responsible for, a 911 dispatch center, 6000 line phone system, etc. And I owe it all to my parents buying me a scanner when I was about 14.

I think that TK-862 might be able to be programmed into the 70cm amateur band. That might allow you to listen in on some local repeaters. A good way to learn about amateur radio is to listen. When you get your license you can set it up to transmit.

 

[kenwoodgeek]

That's a very interesting story! I've pretty much been into radios since last year when I saw my bus driver talking on her's. I ended up getting a scanner for Christmas. Then, what do you know, my dad tells me to go grab some "junk" he saved from one of his buildings in a box in the back of his work van and it turns out to a Kenwood TK-862G complete with microphone, antenna, and everything! Not to mention I got two portable TK-3160's in the same box which we sold. I'm also interested in getting a CB here pretty soon. I've seen some pretty cheap ones on eBay.

It looks like you've got a huge responsibility there. That must be an interesting job.

And thanks for the advice on my radio. Unfortunately, all the 400 MHz range amateur repeaters in my area operate on frequencies ranging from 442-444 MHz, while my radio is only designed to get 450-490 MHz. Luckily though, it's close enough that, although the programming software gives me an error message, I can still pick up the amateur bands on it just fine!

 

[mmckenna]

And thanks for the advice on my radio. Unfortunately, all the 400 MHz range amateur repeaters in my area operate on frequencies ranging from 442-444 MHz, while my radio is only designed to get 450-490 MHz. Luckily though, it's close enough that, although the programming software gives me an error message, I can still pick up the amateur bands on it just fine!

Do some searching on TK-862 "out of band". A lot of these radios can be programmed outside the limits of what the programming software will allow if you know the correct tricks. I've did some quick searches and there are people that have put TK-862's on the amateur bands without any hardware modifications.
Might be worth a shot.
Or, save up some cash and get one of the cheap Chinese two way radios. They'll do what you need.

 

[mmckenna]

It looks like you've got a huge responsibility there. That must be an interesting job.

Yeah, it's a great job, but the people I work with really make the difference. Getting into a group of dedicated professionals that know how to do their job and don't take themselves too seriously makes the time fly by.

 

[kenwoodgeek]

I see. Yeah, I'm pretty confident that the radio will work great on amateur bands, but I will also do some research.

Like I said, thanks again for all the help. I figured out that the DTMF tones are alright to use on the frequency, and that's what I have it programmed to now, although I might take them off in the future.

Anyway, I made a little video for you showing how it works and stuff. The dispatcher said I could call in on Friday, so I did and got it on video.

https://www.youtube.com/watch?v=imbO98rKfeA

 

[mmckenna]

Nice. It's great that the dispatchers have been working with you on this.

Sounds like it's working well.