Sometimes radio amateurs suggest that phonetics are not needed on VHF FM.  (See examples here and here.) Sometimes it even sounds like it’s a bad thing to use phonetics on FM.  It is inefficient and slows things down. I can see the logic behind this because with decent signal strength, demodulated FM audio is usually quite clear and easy to understand.

Here’s what I wrote in my VHF FM Operating Guide, also downplaying the need for phonetics:

The use of phonetics is not usually required due to the clear audio normally associated with frequency modulation. Still, sometimes it is difficult to tell the difference between similar sounding letters such as “P” and “B”. Under such conditions, use the standard ITU phonetics to maintain clarity. Many nets specifically request the use of standard phonetics to make it easier on the net control station.

The FCC Technician exam gives the topic of phonetics a light touch with just these two questions:

T1A03 (D)
What are the FCC rules regarding the use of a phonetic alphabet for station identification in the Amateur Radio Service?

A. It is required when transmitting emergency messages
B. It is prohibited
C. It is required when in contact with foreign stations
D. It is encouraged

And this one:

T2C03 (C)
What should be done when using voice modes to ensure that voice messages containing unusual words are received correctly?

A. Send the words by voice and Morse code
B. Speak very loudly into the microphone
C. Spell the words using a standard phonetic alphabet
D. All of these choices are correct

Use Phonetics

In practical radio operating, there are a number of things that can degrade communication, usually by creating noise sources that compete with the voice modulation. Most of these are a factor even if the RF signal is strong:

• A noisy environment at the receiving end (e.g., background noise such as road noise in an automobile)
• A noisy environment at the transmitter (e.g., background noise such as wind noise outdoors)
• Poor frequency response of the overall system (e.g., high frequencies may be lost in the transmitter, receiver or repeater, making it more difficult to understand the voice communication).
• Hearing impairment of the person receiving the audio (I’ve heard that we are all getting older)
• Difficulty understanding the person speaking (poor enunciation, unfamiliar dialect or accent, etc.)

So I say go ahead and use phonetics on VHF FM, especially for critical information such as your call sign. FM communication is not always clear and easy to understand. It suffers from the same signal-to-noise problems as other voice modes. (Perhaps not as bad as SSB on HF, but it’s still a factor.) In most cases, you’ll want to stick with the standard ITU phonetic alphabet (also known as the NATO alphabet).

Many nets request that you use ITU phonetics when you check in. Imagine being the Net Control Station for a net and having everyone making up their own phonetics. You would have call signs coming at you with all kinds of random words associated with them.  It is much better to have consistency. However, there are times when you might want to use alternative phonetics. See the HamRadioSchool.com article: Phonetic Alphabets for more insight on that.

73, Bob
Kilo Zero November Romeo

One question we often hear from new hams (and maybe some not-so-new hams) is “why can’t I get into the repeater?” They get their hands on a new radio, set it up to use one of the local repeaters and it’s not working. Now what?

There can be a whole bunch of reasons why you can’t get into a repeater so it is difficult to come up with a quick fix for all situations. However, in this article we’ll talk about some basic troubleshooting steps to help diagnose the problem. For this article, I am assuming that your first rig is a handheld vhf/uhf transceiver but the general approach will work with mobile or base transceivers, too.

FOT

Many times the problem is due to not having the transceiver programmed correctly. The key things we have to pay attention to are: Frequency, Offset and Tone (FOT). To access a repeater you need to have its Frequency entered into your radio, have its transmit Offset set correctly and have the right CTCSS Tone turned on. You might not need to check all of these things in that exact order but it is a good way to approach the problem. Using the programming software (and suitable cable) for your radio can be a big help.

Frequency –First you need to program in the frequency of the repeater you want to access. The actual key strokes or knob turns will depend on the particular model of radio so consult your operating manual. The frequency you enter is the repeater transmit frequency which will be your receive frequency. Repeaters are always referred to by their transmit frequency, which can be found in an online or printed repeater directory.

Offset – Next, we need to make sure the proper transmit offset is programmed into the radio. This is the difference in frequency between the repeater transmit frequency and its receive frequency. Your transceiver will automatically shift your frequency when you transmit, if you have the right offset programmed. In most parts of the US, the standard offset is 600 kHz on the 2m band and 5 MHz on the 70cm band, and can be either in the positive (+) or negative (-) direction. Your repeater directory will list the offset and direction. Most radios will default to the standard offset but you may have to select + or – offset. Usually a + or – symbol will appear in the display to indicate the offset selected.

As an example, my repeater is on 447.725 MHz with a – 5 MHz offset. So you would enter 447.725 MHz into your radio, make sure the offset is set to 5 MHz and select – as the offset direction. You can verify that your radio is programmed correctly if you see 447.725 MHz displayed during receive, which should change to 442.725 MHz when you push the transmit button.

Tone – For most repeaters, you will need to transmit a CTCSS tone to access the repeater. (CTCSS is Continuous Tone Coded Squelch System.) Repeaters with carrier access do not require a tone, so you can skip this step. This is normally a two-step process: set the tone frequency and then enable the tone. Sometimes this is done with one selection (with “Off” being an option for the tone frequency). Some radios have separate settings for the transmit tone and receive tone. For now, just leave the receive tone off, since it can be a source of confusion. The tone that you need to set is your transmit tone. Most radios display a “T” somewhere on the display when the tone is enabled. Again, check your operating manual.

Kerchunk

At this point, you should be ready to try accessing the repeater. After listening on frequency for a minute, transmit and identify using your callsign. On most repeaters, you will hear a short transmission coming back from the repeater along with a courtesy beep. A courtesy beep is just a short audio tone or tone sequence that occurs after someone finishes transmitting. If you hear the beep, then you accessed the repeater. Congratulations! Go ahead and make a call and see if someone will come back to you.

Troubleshooting

What if you don’t hear the repeater coming back to you? Then we need to go into troubleshooting mode. If the radio is new, you might wonder if it is even working properly. The quality level of today’s equipment is quite good, so most likely your radio is just fine. Still, you may want to check it out.

First, you can check to make sure your radio is receiving properly. In the US, a good way to do this is to tune into your local NOAA weather transmitter.These transmitters are on the air continuously, operating on 162.400, 162.425, 162.450, 162.475, 162.500, 162.525 or 162.550 MHz. These frequencies are outside of the 2m ham band but most ham transceivers are able to listen to these frequencies. You’ll want to set this frequency as simply as possible…use the keypad or VFO mode to enter it directly. In most cases, you can just try the short list of frequencies until you hear the transmitter in your area.

Next, you might want to know that your radio is able to transmit a signal. The best way to do this is find a local ham nearby that can run a simplex check with you. By nearby, I mean within 5 miles or so, because we want someone so close that there is no question about whether they should be able to contact us. Program your radio to a 2m simplex frequency such as 146.52 MHz (the National 2m FM Simplex Frequency). For this test, we do NOT want the transmit offset turned on…the radio needs to be set to simplex. You can double check this by looking at the display when transmitting—it should show 146.52 MHz (transmit frequency is the same as the receive frequency). For this test, we don’t care about the transmit tone…it can be on or off. Have the other ham give you a call and see if you can contact him. If you happen to have a second transceiver, you can try this test yourself – just see if each radio can hear the other one. One warning: do this on a simplex frequency. Trying to go through a repeater can really confuse things because you may not have the offset and tone set properly. Even more confusing is that one radio can “desense” the other radio, which means that the other radio’s receiver will be overloaded and not able to receive the repeater’s signal. Using simplex keeps things simple.

The final thing to check is whether your signal is able to reach the repeater. Well, that is a bit of a challenge! For starters, are you sure you are within range of the repeater? Have you ever heard a signal from this repeater, and was it full scale on your S meter? You may want to ask local hams about whether you should be able to hit the repeater from your location with the radio you are using. For that matter, you might want to check if the repeater is actually on the air – they do go down from time to time.

This brings us to an important point about the use of handheld transceivers. They are really, really handy. How else can you carry a complete ham radio station in your hand? Well, the tradeoff is that an HT operates with relatively low power (5 watts or less) and has a compromised antenna. (The standard rubber duck antenna on an HT is a very convenient crummy antenna.) You may need to add some extra umph to your signal by improving the antenna. Some good dualband choices are a longer whip such as the RH 770 antenna or a magnetic-mount mobile antenna placed on a vehicle or on other metal object.

Summary

In this article, I’ve tried to provide some assistance in figuring out why you aren’t hitting the repeater. The most common problem for newly acquired radios is getting them programmed (remember FOT: Frequency Offset and Tone). Once you have that right, it is usually just making sure that you have enough signal to make it to the repeater.

73, Bob K0NR

Note: this article is adapted from Hey, Why Can’t I Access the Repeater? on hamradioschool.com

My UHF repeater has been operating on 447.725 MHz here in Monument for a couple of decades now. It started out as a classic “pet repeater” project and has been operating from my basement all this time. Over time it has picked up additional users and has turned into the de facto hangout for our local radio club.

The repeater system has gone through a number of revisions over the years, including the RF transmitter and receiver. I wanted to retire the pair of Motorola Mitrek mobile radios I have been using when they started to exhibit a few lose connections. Really though, I thought it was time for some synthesized, modern RF gear in a compact package.

When Yaesu offered an attractive price on their DR-1X Fusion repeater, I jumped at the chance. Initially, I put it on the air in mixed analog-digital mode with the repeater automatically switching modes to handle either analog FM or C4FM digital. I used the internal controller of the DR-1X which is quite simple and has limited functionality. (The SCOM 7K controller got put on the shelf for a while.) The DR-1X supports using an external controller but implementing the mixed analog-digital mode is…well…challenging. (Various people have figured out ways to do it with modifications to the DR-1X or using additional hardware.)  After 10 months of operation, I decided to reinstall the full-featured SCOM 7K controller, enabling quite a few features including a 2m remote base, synthesized speech, automatic scheduling and weather alerts. This does mean giving up the C4FM mode but usage was minimal anyway.

The SCOM 7K repeater controller has been in service for decades, handling multiple receivers and transmitters, very configurable with programmable macros. SCOM has long since moved on to a newer, improved model but my 7K just keeps on ticking. The 7K has the voice synthesis and autopatch options installed, so, yes the repeater has an autopatch (not that anyone cares). A Yaesu FT-7800R is used as a 2m remote base and the duplexer is a classic Decibel Products. Not shown in the photo is a Bearcat WX100 weather receiver that is used to transmit weather information when an alert occurs in our area.

I’ve documented the wiring diagram and configuration used here: k0nr-repeater-construction-notes

This was a good opportunity to clean up some of the cabling and physical mounting that had degraded over time. (A kluge here, a kluge there and entropy takes over.) I am happy with the result.

73, Bob K0NR

Wouldn’t it be cool if we had one digital communications format for the VHF/UHF amateur bands with all equipment manufacturers offering compatible products? The basic modulation and transport protocol would be standard with manufacturers and experimenters  able to innovate on top of that basic capability. There would be plenty of room to compete based on special features but all radios would interoperate at a basic level. You know, kind of like analog FM.

Yeah, we don’t have that. 🙁

73, Bob K0NR

Graphic: Adapted from HamRadioSchool.com

I own a variety of Yaesu ham radio transceivers and like them a lot. Except for that one little annoying feature that the FM rigs have: WIRES.

About once every two weeks, one of the local radio hams gets on the repeater with a DTMF beep at the start of every transmission. We’ve come to expect it now, so the first question to the ham is “are you by chance using a Yaesu radio?” They always say “yes” and then we talk them through the process of turning off the WIRES “feature.”

The WIRES function sends a DTMF signal at the start of every transmission for use with Yaesu’s version of internet repeater linking (which is not used much in the US).  The problem is that it is very easy to bump the wrong button on your radio and accidently get it into this mode. This means that this is mostly a nuisance feature in the US.

I recently came across a way to disable this feature on your Yaesu radio so that it won’t sent the DTMF tone even if you activate it by accident. Basically, you set the WIRES tone to be empty, so nothing is transmitted if you accidentally turn on WIRES. I did not come up with this clever hack…in fact, I am not sure who put this together. (If you do, let me know and I’ll give them credit.) Take a look at this pdf file and follow the instructions to de-WIRES your radio: Turn Off Wires

73, Bob K0NR

A few weeks back, I was wasting time doing important research on the internetz when I came across the Baofeng UV-5R Dualband Handheld Transceiver.  This radio seemed to have a boat load of features but the sale price was $65. So I am thinking to myself, just how good is a $65 radio?

The last time I went out to a nice restaurant, I blew through $65 pretty quickly so this was not going to be a large purchase. In fact, I realized that we now have HT’s priced low enough to be an impulse buy. As one of my ham buds told me, “filling up the gas tank of my truck costs more than this radio!”

So, of course, I soon broke down and ordered one and it showed up on my doorstep a few days later. I’ve been using it off and on for a few weeks now. I’ve also noticed that there is a real buzz on the interwebz about this little radio. There is usual Yahoo Group (baofeng_uv5r) and youtube videos.

Here’s the short story:

While not perfect, for $65, this radio is impressive.

Besides using the radio and receiving good signal reports, I did check the receive sensitivity, transmit power and frequency — all good. There are quite a few reviews out there, so take a look at articles by W0HC, PD0AC and OE1RFC. Also, there have been quite a few reports of quality problems with this radio…probably more defects than equipment from the more established ham equipment vendors. See the Yahoo Group discussion to understand this better.

Similar to other radios from China, this radio has a quirky user interface…not as easy to use as my Yaesu FT-60. This means that the programming software is a necessity to get the radio set up correctly, which is the major downfall of the rig. The free software program is crapware, with many people reporting a variety of problems with installation and operation. I did finally get it to work, but it was very frustrating.

I find myself grabbing this HT when I head out the door and leaving my other radios sitting in the desk charger. Someone pointed out to me that the low price of this radio makes it an easy choice — if it gets dropped, broken, lost or stolen, I am only out a tank of gas. While I am kidding about the “disposable radio” idea, the low cost does affect how I use it.

73, Bob K0NR

In a previous blog posting, I wrote about the construction of a portable VHF/UHF crossband repeater. I published the results of this project in my FM/Repeater column for the Fall 2008 issue of CQ VHF Magzine. I’ve adapted portions of the article to provide an update here.

To deal with the issues of identification and control, I decided to use a repeater controller to control two independent 2M/70 cm transceivers. Most repeater controllers are set up for conventional repeater control with a fixed receiver and fixed transmitter. What I needed was a controller that incorporated the concept of two independent transceivers that could be linked together, independently controlled and independently identified. The NRHC-6 Bridging Repeater Controller is designed to handle this specific case of connecting two transceivers. The block diagram of this crossband repeater system is shown in Figure 1.

I used a pair of FT-7800R transceivers which have a packet port on the rear panel that provides a convenient interface point for the repeater controller. This port has the required transmit audio, receive audio, PTT line and squelch line. The squelch line indicates the condition of the receive squelch, including the effects of CTCSS decode if enabled in the transceiver. (Not all transceivers behave this way… some only provide carrier squelch even if CTCSS decode is enabled.) Table 1 shows the signals available from the packet port and how they are used in the repeater interface.

Table 1. FT-7800R Packet Port

The NHRC-6 controller has a versatile feature set that requires some programming to make it work. It supports two radio ports which can be configured to handle two back-to-back simplex radios. The controller has DTMF control, which can be accessed from either radio port. The five saved setups are handy for storing away specific repeater configurations. Each radio port can have its own courtesy tone and CW identifier, along with the usual set of hang timer, ID timer, timeout timer, etc. The crossband repeater can be turned on and off remotely using DTMF on either band.

Figure 1 shows two separate antennas, one for 2 Meters and one for 70 cm. In most cases, I use one dualband antenna and a 2M/70 cm duplexer to allow the two radios to feed the antenna. I also keep the radios set at less than full power to minimize the heat dissipation problem.

This crossband repeater is housed in a portable case that has standard 19-inch rack hardware (Figure 2). The two transceivers are mounted to a 19-inch shelf using their normal mobile mounts. The NHRC-6 controller has its own 19-inch rack mountable chassis. The case has a front and rear panel covers that snap on, protecting the equipment during transit. The system runs off of 12 VDC. I did not include an AC power supply inside the case. Depending on the location, I simply connect the repeater to a 12 volt car battery or a compact AC switching power supply.

I’ve used this repeater as a standalone UHF repeater by adding a small mobile duplexer to provide transmit/receive isolation. Of course, in this case, the two transceivers both operate on the 440 MHz band with 5 MHz offset. I’ve also used it as a crossband repeater, usually to extend the range of a 2 Meter repeater.

– 73, Bob K0NR