Category Archives: Repeater

The 2 Meter Band: Much More Than FM

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Way back in the Wayback machine, when I was working on getting my Technician license (in the 20th century), I recall looking at the frequency bands available to Techs. Technicians had operating privileges for everything above 50 MHz, which looked like a lot of useful spectrum to me. The idea at the time was that Technicians were exploring the new frontier of amazingly high frequencies. Since then, the Technician license has morphed to be the entry level license.

ICOM has a good graphic that shows all of the ham bands and shows the common subbands for various modes. I snipped out the portion that covers the most popular VHF/UHF bands (below). Wow, look at all the stuff you can do! Note that the 2m band offers 4 MHz of spectrum, big enough to fit eleven 20 meter bands inside it. (Yeah, yeah, the propagation is a lot different.)Speaking of bandwidth, take a look at the 70 cm band, with 30 MHz of spectrum. (Not shown is the 23 cm band, which spans 60 MHz.) The higher you go in frequency, the more spectrum there is.

Most people think of the 2-meter band as just FM and repeaters, but it is much more than that. I copied the 2-meter band graphic and added my own notatation on the various uses of the band.

Much of the band is allocated to FM, which is consistent with the popularity of the mode. I didn’t mark all of the FM segments, so refer to the color coding to see them. But there is much more than FM simplex and repeaters. Down on the low end is the CW-only segment and EME activity (Earth-Moon-Earth or moonbounce). The “weak-signal” enthusiasts tend to use the SSB portion, with the SSB calling frequency of 144.200 MHz (Upper Sideband). You may also hear CW in the SSB subband because radio hams flip back and forth between the modes depending on propagation.  Meteor scatter is mostly done via the WSJT-X mode of MSK144 around 144.140 MHz. I forgot to include FT8 on the first posting but I have since added it in, around 144.174 MHz. FT8 is not that common on 2 meters but I have made a few contacts with it.

Automatic Packet Reported System (APRS) activity is on 144.390 MHz, using FM-based 1200-baud packet radios. Other packet radio usage is not shown but is usually around 145.01 MHz. The 2m band is very attractive for satellite use, with VHF propagation properties and manageable doppler shift for Low Earth Orbit (LEO) satellites. The downlink from the International Space Station (ISS) is usually 145.80 MHz.

Over time, I’ve used all of these 2m modes mentioned above, with the exception of EME. I am still working on that one and I hope to have a new 2m Yagi installed sometime this year that will enable it.

73 Bob K0NR

Go Ahead and Use Phonetics on 2m FM

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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).

Graphic courtesy of HamRadioSchool.com

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

Go Ahead and Call CQ on 2m FM

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The conventional wisdom in amateur radio is that we should not call CQ when using FM on the VHF and UHF bands, especially on repeaters. The reasoning for this is that during normal VHF/UHF FM operating, radio amateurs are tuned to a specific frequency and will easily hear a call on FM.

Compare this to the HF bands, where the other ham is generally tuning around to find someone to contact and stumbles onto your transmission. In that case, you want to make a long call (CQ CQ CQ Hello CQ This is Kilo Zero November Romeo calling CQ CQ CQ…) so people tuning the band will find you and tune you in. On VHF/UHF FM, the assumption is that the other hams have their radio set on the repeater or simplex channel being used and will immediately hear you. FM communications are often quite clear and noise free, which also helps. The normal calling method is to just say your callsign, perhaps accompanied with another word like “monitoring” or “listening.”  For example, I might say “KØNR monitoring.”

Question T2A09 in Technician exam pool reinforces this idea:

T2A09 (B)
What brief statement indicates that you are listening on a repeater and looking for a contact?
A. The words “Hello test” followed by your call sign
B. Your call sign
C. The repeater call sign followed by your call sign
D. The letters “QSY” followed by your call sign

Gary/KN4AQ wrote this tongue-in-cheek article HamRadioNow: Do NOT Call CQ on Repeaters which says that calling CQ on a quiet repeater works well because it is likely that someone will come on and tell you not to call CQ. Gary wrote:

So I trot out my standard advice: make some noise. I even recommend calling CQ, because that’s almost guaranteed to get someone to respond, if only to tell you that you’re not supposed to call CQ on repeaters.

There is also an interesting thread on the topic on reddit: 2 meter calling frequency.

Scanning and Multitasking

Some important things have changed in our use of VHF/UHF FM over past decades.  The most important shift is dispersion of activity: while the number of VHF/UHF channels has increased, the total amount of VHF/UHF radio activity has declined. This means that we have tons of channels available that are mostly quiet. Tune the bands above 50 MHz and you’ll hear a lot of dead air. In response to this, some hams routinely scan multiple repeater and simplex frequencies. While getting ready for Summits On The Air (SOTA) activity, I’ve had hams ask me to make a long call on 146.52 MHz so they can be sure to pick me up on scan.  

Another factor that comes into play is the multitasking nature of our society. Hams don’t generally sit in front of a 2m radio waiting for activity to occur. More commonly, they are doing something else and listening to the FM rig in the background. VHF FM is the Utility Mode, always available but not necessarily the top priority. A short call (“KØNR listening”) on the frequency can easily be missed.

Recommendations

My conclusion is that the Old School “KØNR Monitoring” style of making a call on VHF is no longer sufficient. First off, it sends the message of “I am here if you want to talk to me.” If that’s your intent, fine. However, if you really want to make a contact, being more explicit and a bit assertive usually helps. Follow Gary’s advice and make some noise.

For example, during a SOTA activation I’ll usually call on 146.52 MHz with a bit of a sales pitch.  Something like: “CQ CQ 2 meters, this is Kilo Zero November Romeo on Pikes Peak, Summits On The Air, anyone around?” This is way more effective than “KØNR Monitoring.”  I might also include the frequency that I am calling on, to help out those Scanning Hams. Something like “CQ CQ 146.52, this is KØNR on Pikes Peak, Summits On The Air.”  Note that these calls are still pretty much short and to the point, only taking about 15 seconds. This is a lot shorter than the typical HF CQ.

If I am driving through another town and want to make contact on the local repeater, I will adjust my approach accordingly. For example, on a relatively quiet repeater, I might say “CQ, anyone around this morning? KØNR mobile I-25 Denver.” Or if I have a specific need, I’ll go ahead and ask for it. “This is KØNR looking for a signal report.”

Keep in mind that VHF/UHF operating tends to be local in nature, so it makes sense to adapt your approach to both local practice and the specific situation.

  • It’s OK to call CQ on VHF FM, make some noise on the frequency.
  • Give other operators a reason to contact you.
  • Don’t make your CQ too long, maybe 15 to 20 seconds.
  • The callsign/listening approach is fine too.

Those are my thoughts. What do you think?

73 Bob K0NR

FOT: Frequency, Offset and Tone

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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

DMR Hotspot from SharkRF

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Amateur adoption of Digital Mobile Radio (DMR) continues to increase, with a number of new innovations playing out. It was way back in 2012 when I wrote this article about DMR for CQ VHF Magazine: TRBO Hits the Amateur Bands. 

A few years ago, I picked up some used MOTOTRBO gear to use on our local DMR repeater system (MOTOTRBO is Motorola’s version of DMR). Here in Colorado, the Rocky Mountain Ham Radio group has been instrumental in establishing a great network of DMR repeaters, a real asset for Colorado radio amateurs. See Rocky Mountain Ham Radio TRBO/DMR Network.  Worldwide, the DMR-MARC organization has created a robust network of MOTOTRBO repeaters in over 60 countries.

A more recent development is the establishment of the BrandMeister Network, which promotes more of a homebrew approach to DMR. This evening, the BrandMeister dashboard shows 634 industrial repeaters (commercial equipment), 263 homebrew repeaters and over 1300 hotspots of various types.  A variety of DMR hotspots are available, including the DV4mini. I’m not going try to list all of the hotspots available as I’m sure I’ll miss something.  The SharkRF openSPOT caught my attention because of this excellent review by John ‘Miklor’ K3NXU. Because of its popularity, the openSPOT is on backorder (price: 182.5 Euro).

This HamRadioConcepts video walks through the setup and basic operation.

I thought the openSPOT would be a good widget to have around the shack. It is a standalone hotspot, so I don’t have to dedicate a computer to it. Also, it is very turnkey…no assembly required…but some configuration to work out. Its user interface is a web page that you access via your local network…nicely done. I got it working in less than one hour and have been fiddling around with it ever since.

Hotspots are a funny item. They have very limited RF range, so their main purpose is to provide local RF access into the network (just like your Wi-Fi hotspot). One role they play is to provide fill-in coverage when no repeater is available. Another role they fill is being a personal device that can be connected to your favorite reflector or talk group.

I should point out that the openSPOT also operates as a D-STAR and Yaesu Fusion (YSF) hotspot. You just change the configuration of the modem and it starts speaking the selected modulation. More surprising is that I was able to use a YSF handheld radio to talk to the openSPOT which routed me to a DMR talkgroup. Yes, a Yaesu YSF radio talking on DMR.

The first thing I noticed when listening to some of the more active talk groups is that it seems like every person getting on the system said “I just got this Tytera MD-380 radio and you are my first DMR contact.” OK, sometimes it was a Connect Systems or Motorola radio but the MD-380 at around $100 is having a big impact. I picked up an MD-380 and while its not quite as nice as my Motorola, I really do like the radio. (Note that there are other low cost DMR radios that have serious technical issues.) There will be other radios on the market…the technology will keep improving and improved models will hit the market. Right now, everyone is wondering who will create a good dualband 2m / 70cm transceiver for DMR.

I see some very strong technology and market trends in play here that are going to impact the ham radio world. First off, DMR is a true industry standard (ETSI),  well designed and documented. Second, we are seeing multiple radio vendors offering competitive, low cost transceivers. Third, there is high quality commercial repeater gear available from land mobile providers such as Motorola and Hytera. But there’s one more thing that really tops this off: the number of ham-built products emerging that are focused on DMR. This is classic ham radio adaptation and innovation that leverages commercial gear for ham radio use.

Stay tuned…this is going to be interesting!

73, Bob K0NR

The Cacophony of Digital Voice Continues (Part 2)

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Digital transmissionThis post is a continuation of The Cacophony of Digital Voice Continues (Part 1), so you probably should read that one first.

All of the popular amateur digital voice (DV) systems (D-STAR, DMR and YSF) use the AMBE vocoder (voice codec) technology. This technology was developed by Digital Voice Systems, Inc. and is proprietary technology covered by various patents. The use of proprietary technology on the ham bands causes some folks to get worked up about it, especially proponents of an open source world. See my blog posting: Digital Voice at Pacificon and this presentation by Bruce Parens K6BP: AMBE Exposed. Codec2 is an alternative open voice codec developed by David Rowe, VK5DGR. David is doing some excellent work in this space, which has already produced an open codec that is being used on the ham bands. FreeDV is an umbrella term for this open codec work. Here’s a recent video of a presentation on FreeDV by VK5DGR.

It will be interesting to see if and how Codec2 gets adopted in a DV world already dominated by AMBE. After all, a new codec is another contributor to the digital cacophony. On the HF bands, it is easier to adopt a new mode if it can be implemented via a soundcard interface (which FreeDV can do). Any two hams can load up the right software and start having a QSO. The same is true for weak-signal VHF/UHF via simplex. (Note that Flexradio also supports FreeDV, showing how Software Defined Radio (SDR) has an advantage with adopting new technology.)  VHF/UHF repeaters are trickier because you must have a solution for both the infrastructure (repeaters and networks) as well as the user radios.

The vast majority of digital repeaters support just one digital format. For example, a D-STAR repeater does not usually repeat DMR or YSF transmissions. Interestingly, DMR and YSF repeaters often support analog FM via mixed mode operation for backward compatibility. It is definitely possible to support multiple digital formats in one repeater, but the question is will large numbers of repeater owners/operators choose to do that? With existing DV systems, the networking of repeaters is unique to each format which represents another barrier to interchangeability. In particular, most of the DMR infrastructure in the US is MOTOTRBO, which won’t ever support D-STAR or YSF.

In the case of a new vocoder, we can think of that as just a new format of bits being transported by the existing DV protocol. DMR, for example, does not actually specify a particular vocoder, it’s just that the manufacturers developing DMR equipment have chosen to use AMBE technology. So from a technical viewpoint, it is easy to imagine dropping in a new vocoder into the user radio and having it work with other identical radios. Of course, these radios would be incompatible with the existing installed base. Or would they? Perhaps we’d have a backwards compatibility mode that supports communication with the older radios. This is another example of putting more flexibility into the user radio to compensate for DV incompatibilities.

One objection to AMBE is the cost of the technology, especially when compared to free. When D-STAR radios first started using AMBE codec chips, the chip cost was rumored to be $25 to $50, but I don’t have a solid source on that. Now, I see that Tytera is selling a DMR handheld at around $100, including AMBE technology inside, so the codec can’t be very expensive. If a free codec starts to be a credible threat, it will put additional pricing pressure on the AMBE solution.

A potential advantage of Codec2 is superior performance at very low signal-to-noise ratio. We’ve all experienced the not-too-graceful breakup of existing DV transmissions when signals get weak. Some of the Codec2 implementations have shown significant improvement over AMBE at low signal levels.

Conclusions

Repeating a key conclusion from Part 1:

  • For the foreseeable future, we will have D-STAR, DMR and YSF technologies being used in amateur radio. I don’t see one of them dominating or any of them disappearing any time soon.

Adding in these conclusions for Part 2:

  • Codec2 will struggle to displace the proprietary AMBE vocoder, which is well-established and works. The open source folks will promote codec2 but it will take more than that to get it into widespread use. Perhaps superior performance at low signal levels will make the difference.
  • Repeater owner/operators will continue to deploy single-DV-format repeaters. This will make multiformat radios such as the DV4mobile be very attractive. In other words, we will deal with the digital cacophony by having more flexible user radios. This will come at a higher price initially but should drop over time.

Repeating this one from Part 1:

  • A wild card here is DMR. It benefits from being a commercial land mobile standard, so high quality infrastructure equipment is available (both new and used gear). And DMR is being embraced by both land mobile providers (i.e., Motorola, Hytera) and suppliers of low cost radios (i.e., Tytera, Connect Systems). This combination may prove to be very powerful.

Well, those are my thoughts on the topic. I wish the DV world was less fragmented but I don’t see that changing any time soon. What do you think is going to happen?

73, Bob KØNR

Rehab for the KØNR Repeater

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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.

k0nr-repeater3When 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

Digital Voice Balkanization

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Digital transmissionWouldn’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

Hey, My Yaesu Beeps When I Transmit!

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FT-8800R_thumbI 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

 

This Spewed Out of the Internet #25

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0511-0701-3118-0930Here’s another update of interesting important stuff spewing forth from the internet.

I put my two presentations from HamCon Colorado out on the web:  Practical Amateur Radio Measurements and Mountaintop VHF in the Colorado High Country . Also, check out Kelly N0VD’s blog posting on the event.

Having trouble finding a repeater to use on VHF? Check out my Shack Talk article on HamRadioSchool.com

KB5WIA provides some good tips on EME operating.

Hans PD0AC addresses the question: What’s the Best Chinese Dual-band HT? For best price/performance, he selected Baofeng UV-B5/UV-B6 (and I agree).

The Noise Blankers continue to publish their Ham Hijinks. Remember: Do Not Take These Guys Seriously. Seriously. Do not do this. Seriously.

There’s lots of great ham radio events coming up this summer. This weekend is the CQ Worldwide VHF Contest, the only “true VHF contest” out there since only the 50 MHz and 144 MHz bands are used. Then there’s the Colorado 14er Event, which includes Summits On The Air (SOTA) activations, on August 4th. (Don’t forget to check out the great new Colorado 14er Shirts!)  The Colorado QSO Party is another great operating event, on August 31st.

Remember: There is no such thing as ground.

Think about it: an infinitely large electrical node with zero impedance able to sink an infinite current. Not likely.

73, Bob K0NR

FCC Grants Waiver on TDMA

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fcc-1From the That Took A Long Time department, the FCC granted a waiver requested by the ARRL that clarifies the rules concerning the use of TDMA (i.e., MOTOTRBO or DMR) on the ham bands. I posted on this topic way back in March 2011, so refer to that article for the background. Update: ARRL article posted here.

I was surprised to find that the FCC quoted my comments that I filed on this proceeding:

Some commenters state the proposed rule change “removes an ambiguity in Part 97 concerning the use of single slot TDMA technology” and it “enable[s] and encourage[s] the adoption of spectrally efficient narrowband technology.”  Comments of Robert Witte at 1.

OK, fine, it was buried in the footnotes but I appreciate the mention. I can now die in peace knowing that my name is in the FCC record and not associated with a rules violation 🙂

Thanks to Jeff K0RM, for pointing this out.

73, Bob K0NR

Proper Kerchunking

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Recently, on one of the email reflectors associated with repeater owners, someone asked how to deal with kerchunkers on the repeater. The term kerchunk means to key up the repeater to see if it is there. It just takes a quick push of the Push-to-Talk (PTT) button on the transceiver to bring up most repeaters, resulting in a kerchunk sound.

It seems that this repeater owner had someone that was kerchunking his repeater on a regular basis and it was making him looney. This led to the usual discussion of whether kerchunking is acceptable, legal or  moral and whether it should or should not be considered a capital offense.

Clearly, some radio amateurs have not been schooled in the proper way to kerchunk a repeater. The proper method for kerchunking is to key the transmitter and say your callsign, followed by the word “kerchunking”. This simultaneously identifies your station and indicates the purpose of your transmission.

To make the practice of repeater kerchunking even more efficient, I am proposing the adoption of these new Q signals:

QKC: I am kerchunking the repeater

QKC?: Are you kerchunking the repeater?

Thank you for your attention to this important topic concerning good amateur practice.

73, Bob K0NR

Seventy Three

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Like many technical activities, amateur radio has its own set of jargon and protocols used both on and off the airwaves. As part of our Technician license course, we cover basic jargon but also encourage the use of plain language. A new Technician recently asked about the use of the term “73” on the local FM repeater, so I am posting this short piece.

Much of amateur radio history and practice is rooted in Morse Code, which traces back to the electrical telegraph. Two shorthand codes you’ll hear on both voice and Morse Code communications are:

73 means Best Regards

88 means Love and Kisses (sometimes Hugs and Kisses)

These codes originated with telegraph operating and are listed in the Western Union 92 Code, a set of numerical shorthand codes. On voice (phone) transmissions, you often hear something like this:

“Great to talk to you, Joe. Thanks and Seventy Three. This is K0NR, clear.”

Since 73 is often used at the end of a radio contact, it almost takes on the meaning of “best regards and goodbye.” “Eighty Eight” is used in a similar manner but is heard much less frequently on the ham bands.

Sometimes you’ll hear 73 expressed as “Seven Three”, which corresponds to how the Morse characters were sent. It is incorrect to say “Seventy-Three’s” since this would literally mean “Best Regards’s”. Of course, most of us have made this error from time to time, very similar to grammatical errors in the English language. (“Somes time we forget to talk good.”)

QRP operators often use 72 instead of 73 because low power operating is all about getting by with less. See W2LJ’s blog.

And I normally use 73 at the end of most ham radio related email messages.

73, Bob K0NR

TechDay 2012 – Your Start in Amateur Radio

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Come join us on Saturday, September 15th, 2012 (9:00 AM to 2:00 PM) at the Tri-Lakes Monument Fire Administration Complex at 166 Second St. in beautiful Monument, CO for a half day workshop aimed primarily at the new Technician Licensees to help them get started in ham radio. While you’re here you’ll learn what it takes to be a ham radio operator, brush up on your DXing skills, test  your own ham radio equipment, check out some sweet mobile radio installations, and ask an Elmer “What’s so cool about 10 meters?”

Getting started in ham radio has never been so much fun!

Presentations

9:30 am – Youth DXpedition to Costa Rica
by Anna Veal WØANT

10:30 am – Mountaintop Operating
by Steve Galchutt WGØAT

11:30 am – Home Station Setup
by Anna Veal WØANT

12:30 pm – Getting On the Air
by Brandon Hippe KDØPWF

1:30 pm – Radio Equipment 101
by Shel KFØUR

* Each presentation is approximately 15 minutes with 5 minutes of Q&A at the end.  Events subject to change

Booths – Open 9AM to 2PM

Get Your Radio Programmed with Local Repeater Freqs by RT Systems
hosted by Kyle Hippe KYØHIP & Cole Turner WØCOL

Check Your Radio Performance
hosted by Bob Witte KØNR

See an HF Station
hosted by Dan Scott WØRO & Stu Turner WØSTU

Ask Any Question – The Elmer Booth
hosted by Paul Swanson AAØK & Shel KFØUR

Understand Mobile Installations
hosted by James Bucknall KDØMFO & Ethan Bucknall KDØMFP

Getting Your Ham Radio License
hosted by Brandon Hippe KDØPWF & Eric Hippe NØHIP

Ham Radio & Public Service
hosted by Randy Meadows KNØTPC

Sponsors

Tech Day 2012 is proudly sponsored by the WØTLM Amateur Radio Club and the  Pikes  Peak Radio Amateur Association.

Get the one page flyer in pdf format here.

Direct any questions to Bob KØNR

The World’s First Disposable HT

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Baofeng UV-5RA 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

Don’t Get Stuck On 2 Meters

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When I first got started in amateur radio (many years ago), one of the engineers that I was working with at a summer job told me “Don’t get stuck on 2 Meter FM”. At the time I was a college student and felt lucky enough to have 1) found time to pass my Novice exam, including Morse Code test, 2) found time to travel 150 miles to the regional FCC office and pass my Technician exam, and 3) scraped up enough money to buy a basic 2 Meter FM mobile rig. I was in Technician ham heaven, playing around on 2 Meter FM, both simplex and repeaters. Oh, and we had this cool thing called autopatch that let you make actual phone calls from your car. I really wasn’t worried about getting “stuck on two”.

Even though my discussions with this Old Fart Experienced Radio Amateur revealed that he didn’t see 2 Meter FM as Real Ham Radio, I could see that he had a point. Two meter FM is only small part of the ham radio universe and it would be easy to just hang out there and miss out on a lot of other things. I was reminded of this recently by K3NG’s post: Things I Wish I Knew When I Was A Young Radio Artisan. I agree with most of his comments with the exception of this one:

Don’t get your start on 2 meter repeaters.

This took me back to the comments from the Experienced Radio Amateur from years ago. I get the point — starting out on 2 Meter FM and Repeaters can give you a limited view of ham radio — but I see it as the perfect platform for getting started. Here’s what is working in my area with new Techs: get them started with a dualband FM rig (usually an HT) so they have some on-the-air success. This also puts them in touch with the local ham community, where we not-so-subtlely expose them to other bands, modes and activities. They hear the other guys talking on the repeater about working DX on 10 Meters and start thinking about how to pursue that as a Tech. From there, it just expands out to all kinds of bands and modes.

Just for the record, I guess I did follow the advice of the Experienced Radio Amateur and managed to not “get stuck on two” (i.e., I’ve worked all of the bands from 80M to 10 GHz, earning WAS, WAC, DXCC and VUCC.)

73, Bob K0NR

The Incomplete List of Ham Radio iPhone Apps

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It was time to upgrade my Verizon Wireless phone, so I decided to move to a smartphone. After pondering whether to go with Android or Apple, I finally settled on the iPhone 4. I still miss the The Real Keyboard on my old LG EnV3, as it is nearly impossible to type on a shrunken touchscreen. But then there’s those apps…

I have been trying out some of the ham radio related applications on the iPhone, so I thought I’d report out what I have found.

Here are a few utilities that I found. These apps doing something relatively simple:

CallBook (Author: Dog Park Software, Cost: $1.99) Simple ham radio callbook lookup that accesses the WM7D database (or QRZ and Ham Call databases if you are a subscriber).

Maidenhead Converter (Author: Donald Hays, Cost: Free) Handy app that displays your grid locator, uses maps and does lat/lon to grid locator conversions.

Q Codes Reference (Author: fiddlemeragged, Cost: Free) This app displays the definition of the common Q Signals (QRZ, QSL, QTH, …)

UTC Time (Author: Michael Wells, Cost: Free) A simple app that displays UTC time and local time.

Sunspot (Author: Jeff Smith, Cost: Free) A simple app that displays solar data from WWV.

Ham I Am (Author: Storke Brothers, Cost: Free) A handy app that covers some basic amateur radio reference material (Phonetic alphabet, Q Signals, Ham Jargon, Morse Code, RST System, etc.) Although I find the name to be silly, I like the app!

There are a few repeater directory apps out there:

QSL.FM Mobile (Author: Robert Abraham, Cost: $2.99) Geolocation repeater directory and call sign lookup.

iHAM Repeater Database (Author: Garry Gerossie, Cost: $4.99) Geolocation repeater directory. This seems to work a lot better than the QSL.FM app.

If you are an EchoLink user, then you’ll want this app:

EchoLink (Author: Synergenics, Cost: Free) The EchoLink app for the iPhone.

There are quite a few APRS apps out there. I have tried these:

iBCNU (Author: Luceon, Cost: $1.99) The first APRS app I was able to get running. It just turned on and worked. It integrates the aprs.fi mapping into the app, so it is easy to use. I recommend this one for most casual APRS users.

OpenAPRS (Author: Gregory Carter, Cost: $3.99) This APRS app integrates into the openaprs.net server. A bit more complicated to set up but looks to be more flexible, too. You might want to check out openaprs.net before buying this app.

PocketPacket (Author: Koomasi, Cost: $4.99) another APRS app. Seems to work fine but I find the previous 2 apps more useful. Note: This app can function as a packet modem connected to a transceiver (no internet required).

Ham Tracker (Author: Kram, Cost: $2.99) APRS app, works OK, uses external maps such as Google and aprs.fi. “Share” feature allows you to send an SMS or email with your location information.

Satellite tracking is another useful app for a smartphone:

ISS Lite (Author: Craig Vosburgh, Cost: Free) A free satellite tracking app for just the International Space Station

ProSat Satellite Tracker (Author: Craig Vosburgh, Cost: $9.99) This app is by the same author as ISS Lite, but is the full-featured “pro” version. Although it is a pricey compared to other apps, I recommend it.

Well, that’s what I have found so far. Any other suggestions?

– 73, Bob K0NR

This is an older posting, see my updated list here

Hacking Away at D-STAR Hardware

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dstarWe’ve been looking at optimizing the performance of the D-STAR repeater here in Monument (W0TLM, 446.8875 MHz), so I’ve been searching the web for information on what other groups have uncovered. Not surprisingly, there has been some creative reverse-engineering and re-engineering of the ICOM D-STAR repeaters.

Here’s a summary of some Good Stuff that I found:

1. NU5D paper on DSTAR Repeater Modifications & Interference Testing

2. A good overview of the ICOM D-STAR repeater block diagram and a few modifications to the ICOM repeaters on the dstar.ca web site

3. The N5EBW LED Board – a drop in board to add transmit/receive LEDs to the ICOM D-STAR repeaters

4. The Utah VHF Society D-STAR page — some of the best technical information and practical evaluation of D-STAR technology

5. A Look Inside D-STAR Modulation – an article I wrote for CQ VHF magazine that explains the vocoder and modulation scheme in D-STAR.

If you come across other D-STAR resources, please let me know.

73, Bob K0NR

Update on the Crossband Repeater Project

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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.

Figure 1. Repeater system block diagram
Figure 1. Repeater system block diagram

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

Pin

Label

Description

Repeater Interface

1

PKD (Data In)

Packet Data Input

Transmit Audio

2

GND

Signal Ground

Ground

3

PTT

Ground to Transmit

PTT

4

RX9600

9600 bps Packet Data Output

5

RX1200

1200 bps Packet Data Output

Receive Audio

6

PKS (SQL)

Squelch Control

CAS

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.

figure-5-crossband-repeater-system
Figure 2. The crossband repeater in a 19-inch rack mount case.

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

Portable VHF/UHF Repeater Project

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My latest ham radio project is assembling a portable repeater for VHF and UHF operation. The basic idea is to package two VHF/UHF transceivers and a repeater controller into a rack mount box that can be easily transported and powered from a 12 VDC source.

I chose the Yaesu FT-7800R for the transceivers since it covers the 2M and 70 cm bands and has a data/packet port for easy access to the required control signals. Specifically, the data port has transmit audio in, receive audio out, squelch signal and PTT (Push To Talk). The repeater controller used is the NHRC-6, which is designed for use as a bridging controller between two transceivers. Most repeater controllers are set up for a conventional repeater configuration, always receiving on one frequency and always transmitting on another. I plan to use the repeater in this mode (on the 70 cm band, with a small UHF duplexer) but also wanted to run the transceivers in a crossband repeat mode. The NHRC-6 handles this quite well, able to route audio in both directions between two transceivers and with identification support for both rigs.

I’ve got the system assembled and I am playing around with the configuration. More to follow, probably in a CQ VHF article.
73 Bob K0NR