Archive for category VHF
This certificate for the CQ Worldwide VHF Contest arrived in the mail today, 1st Place Single Operator All Band for Colorado. Most of these contest awards take so long to arrive, I have usually forgotten all about the contest by the time they show up in the mail.
Last year, I had a pretty good run at it with an excellent 50 MHz sporadic-e opening on Saturday that ran up the QSO and grid totals. See my previous report on the contest here.
73, Bob K0NR
“The Wilderness Protocol” (ref. June 1996 QST, page 85), recommends that stations (fixed, portable or mobile) monitor the primary (and secondary if possible) frequency(s) every three hours starting at 7 AM local time, for five minutes (7:00-7:05 AM, 10:00-10:05 AM, etc.) Additionally, stations that have sufficient power resources should monitor for five minutes starting at the top of every hour, or even continuously.” The primary frequency is the National Simplex Calling Frequency…146.52 MHz. The secondary frequencies are 446.0, 223.5, 52.525 and 1294.5 MHz.
Here in Colorado, the summer months mean that many people head for the mountains. Mobile phone coverage has improved in many parts of the high country but is still not reliable in all areas. Amateur radio VHF/UHF repeater coverage is extensive but also does not cover the entire state.
The Wilderness Protocol is a good idea but is overly complex for practical use. Here’s my proposal to make it much simpler for practical backcountry use:
Principle #1: Don’t ever rely on a radio or mobile phone to get you out of trouble in the backcountry. Your primary strategy must be self-sufficiency. Avoid trouble. Be prepared for the unexpected.
Principle #2: Know what repeaters are available in your area. We have many wide coverage repeaters available but you need to know the frequency, offset and CTCSS tone (if any). The Colorado Connection is a linked repeater system that covers many remote parts of the state.
Principle #3: In remote areas, monitor 146.52 MHz as much as possible. This applies to backcountry travelers, mobile stations and fixed stations.
I’ve been making it a habit to monitor 146.52 MHz in the backcountry. I often come across hikers, campers, fisherman, 4WD enthusiasts, SOTA stations, mobile operators and others monitoring that frequency. It is fun to chat with other radio amateurs having fun in the mountains.
Just my opinion.
73, Bob K0NR
Note: This is a repost of an older article with minor edits.
When I purchased my 2003 Ford Escape, I decided to install multiple ham radios and a bunch of antennas. Mostly I use a Yaesu FT-8900 FM transceiver for operating on the 2-Meter and 70-cm ham bands. A while back, I started getting reports that I had alternator whine on my transmit audio. I was perplexed because I thought I had done a pretty darn good job of installing the radio, including connecting heavy 12V power cables directly to the battery. (See K0BG’s web page for more information on battery connections.) I really wasn’t sure if this was a day one problem (and no one ever told me about the crummy audio) or something that had just started. My first course of action was to ignore it and see if it goes away. This strategy failed miserably as my FCC-licensed spouse continued to report that I was “whining”. Finally, I decided to put my alleged knowledge of electricity to work. I got out my trusty oscilloscope and took a look at the voltage near the transceiver. There was about 800 mV of ripple on the DC voltage, as shown below.
The frequency of the ripple was in the audio range, consistent with alternator whine. The frequency of the ripple increased when I rev’d the car engine, so it was clearly coming from the alternator. I was surprised to find that the size of the ripple did not depend much on whether I was transmitting or not. The transmit current is much higher than the receive current, so I expected the ripple to be worse on transmit.
Then I decided to measure the ripple voltage right at the battery, which is shown below. The peak-to-peak ripple is smaller (about 400 mV) than at the radio but still present. I expected the the voltage to be mostly clean right at the battery.
I pondered what to do next. One approach would be to install a filter to eliminate the ripple. However, filtering out a few hundred Hz signal while maintaining a low voltage drop on the 12V power feed is not trivial. More importantly, I had the sense that the Escape’s electrical system was just not operating properly. I decided to take it to my local mechanic, who tested the alternator and determined that a diode had failed. He replaced the alternator for me and the whine is now gone.
I did measure the 12 volt supply with the new alternator installed and the radio transmitting. I was surprised to find that there is still some ripple, a bit less than 200 mV (shown below). Apparently, this is not enough to disturb the FT-8900 signal.
So that’s the story about my alternator whine.
My spouse says “I still whine sometimes” but it has nothing to do with my ham transceiver.
– 73, Bob K0NR
Spring is finally coming to the Colorado high country so it was time for a SOTA (Summits on the Air) activation. I don’t know which idea comes first: let’s go hiking or let’s play SOTA. I suppose it doesn’t really matter.
I’ve had my eyes on activating Aspen Ridge, which is near our family cabin but I wasn’t sure if the road was open. It turned out to be an easy Jeep ride down Forest Service Road 185 to get close to the summit. Then a half mile hike around and over the occasional snow patch got Joyce K0JJW and me to the summit.
My portable station was a Yaesu FT-60 handheld and a couple of antennas. Shown above is my dualband Arrow II antenna with only the 2 Meter elements installed, resulting in a 3-element Yagi antenna. My other antenna is an omni-directional MFJ-1714 1/2-wave whip antenna, which is a little easier to handle for general use. Often that is the only antenna I bring along but this time I decided to add a few more dB of signal by using the Yagi. I also take along a Yaesu VX-8GR that pings my location on APRS (www.aprs.fi/k0nr-7).
After a few calls on 146.52 MHz FM, I worked KC8I in Woodland Park. A few minutes later, I caught Steve WG0AT operating from another SOTA peak (Mt Herman, W0/FR-063) for the QRP To The Field contest. A little later, I worked Ted N0ZPX who was fishing at Antero Reservoir, then N0VXE mobile near Salida and Ron N0MQJ in Ranch of the Rockies.
This photo shows the beautiful Collegiate Peaks in the background, with plenty of snow still showing. Needless to say, it is a gorgeous view from Aspen Ridge!
73, Bob K0NR
In the Winter 2013 issue of CQ VHF magazine, I wrote about some of the VHF/UHF handheld radios available from China. In that article, I reported on the measured performance of a few of the Wouxun and Baofeng transceivers. One of the Baofeng UV-5R radios that I tested showed harmonic distortion that was a bit high on the 2 Meter band, around -40 dBc.
I recently got my hands on a Baofeng UV-5RA, which is a newer version of the same radio (firmware BFB297), so I wanted to check its performance. Like the two UV-5R models I checked, the power output, transmit frequency and receiver sensitivity were all quite solid on both bands. I was more interested in the harmonic distortion present in the transmit signal.
On the 2 Meter band, the 2nd harmonic measured -48.4 dB relative to the fundamental which is pretty good. Similar to the other radios I measured, the performance in the 70 cm band is a lot better (-56.1 dB).
This radio has significantly better harmonic distortion than the older UV-5R radio. Of course, this is just a single sample, so performance of other radios may be different.
73, Bob K0NR
From 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
A few weeks ago, I was at my day job working diligently on something. I popped up the SotaWatch web site to see of anyone was out activating SOTA summits. Sure enough, Steve (AKA Goathiker, AKA WG0AT) was headed up Mt Herman for the day. (I have recently declared Mt Herman to be the Most Radioactive Summit in Colorado…at least for amateur radio.)
When I had a few minutes break, I went out to my amateur-radio equipped SUV in the parking lot to call Steve on 146.52 MHz. Steve came back to my call and we made a quick contact and he was in the log. Even though he was an easy line-of-sight path away, I had trouble copying him. Opening the squelch revealed that I had a large noisy signal sitting on 146.52 MHz. I didn’t think too much of it and assumed it was coming from the vast array of electronic equipment inside the building.
As I left work that day, I tuned to 146.52 MHz to see how quickly the interference disappeared as I drove away. I was surprised to find that the interference did not go away, it was covering a wide area. On my commute home, the noise was remarkably constant. This interference seems to follow me everywhere! Eventually, it sunk in that the interference was coming from my own vehicle. Huh, I didn’t have that problem before.
When I arrived home, I turned off the ignition and the noise was still there. I started disconnecting everything in sight, trying to make the noise disappear. Finally, I unplugged the cute little USB charger/adapter that was inserted into the cigarette lighter socket. Bingo, the interference disappeared. It seems that this little adapter has a switching circuit in it that is generating a large amount of hash. I have not investigated it fully, but it trashes out a substantial portion of the 2 Meter ham band.
It used to be my favorite adapter. Buyer beware.
73, Bob K0NR
The Committee to Preserve Golf November Tango is pleased to announce the availability of the new GNT Polo Shirt. The origins of the GNT frequency traces back to the incident when three ham radio operators found themselves stranded on the shore of Lake Michigan, calling out in desperation for Gin and Tonic. You may recall the unfortunate circumstances that caused confusion about the correct Golf November Tango calling frequency.
Fortunately, this has all been cleared up and The Committee has authorized the sale of the Golf November Tango shirt, with the official GNT frequency embroidered on it. (It seems that the group is really bad at documenting things, so they figured that if they all had a shirt with the frequency written on it, it could only help. See the logo shown to the left.)
These awesome polo shirts are available online in both mens and womens sizes at the Ham Radio Techwear store. The committee apologizes that these shirts are a little late for Christmas presents, but there is always next year.
Remember, when all else fails, make a call on the GNT Frequency.
73, Bob K0NR
Last week, I had lunch with an old friend, Bdale Garbee (KB0G). Bdale and I had both worked at HP for a number of years and we have been involved in some common ham radio clubs and activities. I followed the test and measurement path with Agilent Technologies when that company was formed, while Bdale stayed with the HP computer business. He is a recognized industry expert in Unix, Linux and all things open source. It is always cool to catch up with him and find out what he has been doing. He recently took early retirement from HP…I am not sure what “retirement” means for Bdale but its not playing shuffleboard at the retirement home!
Coincidentally, a few days later, I came across this video from HamRadioNow of Bdale talking at the ARRL/TAPR Digital Communications Conference. In this talk, Bdale discusses the general theme of making stuff and the satisfaction that is derived from that activity. It is about an hour long so grab a cup of your favorite beverage and take a seat.
By the way, check out the other HamRadioNow videos, especially the videos of the DCC technical talks. Good stuff!
73, Bob K0NR
One of the more popular articles on my web site is Choose Your 2M Frequency Wisely, which explains the 2 Meter (144 MHz) band plan. VHF and UHF band plans are mostly local in nature and there is no one band plan that works across the US or North America. So that article is written specifically for the band plan in my own state of Colorado.
I recently wrote a new Shack Talk article for HamRadioSchool.com that covers the same topic in a more general way for North America. I called this article What Frequency Do I Use on 2 Meters? Please check it out!
- 73, Bob K0NR
As I prepare for the ARRL January VHF Contest, I loaded the latest version of VHF LOG, a software program by Dave W3KM. I have used this free program for many years and it just rolled over to version 4.0 to support Windows 8.
VHF LOG is easy to use while covering the basic contest logging requirements for the usual VHF contests (ARRL January/June/September, CQ Worldwide VHF, etc.). It includes a “Post Contest” mode, which is handy for entering a paper log into your computer for electronic submission.
VHF LOG runs on Windows operating systems, 98SE thru Win8. Check it out.
73, Bob K0NR
Some time ago, I qualified for 50 MHz VUCC from another location (rare grid DM67, operating portable). Lately, I have been racking up grids on 6 Meters from my cabin in DM78. Since a VUCC award is good for a set of locations that are within 200 km of each other, these new contacts count as a separate VUCC award entry.
After the ARRL Logbook of the World (LoTW) added VUCC to the list of supported awards, I started watching my grid count climb. When the grid count hit 200, I decided it was time to apply for VUCC from the new location.
There are a lot of things about LoTW that are a pain but getting this award was easy. A few clicks on the LoTW web page and I submitted an application for 50 MHz VUCC using 203 grids. The fees were significant: $46.45. This breaks out as $12 for the award fee, $1 for endorsement sticker (indicates 200 contacts), $3 for an LoTW application fee and $30.45 for confirming the 203 grids (15 cents per grid). This might seem steep until you compare it to the mailing and other costs of getting 200 confirmed QSL cards. Assuming a 100% response rate and an SASE for each confirmation, it costs more than $1 per confirmed grid or >$200. With a lower response rate, the costs are even higher. And this ignores the time it takes to organize and send out the cards.
I happily paid the fee using my VISA Credit Card and the VUCC certificate arrived in my mailbox a week or so later. This is awesome!
73, Bob K0NR
I happened upon this posting from Hans PD0AC about the Baofeng UV-B5 handheld transceiver. Hans has written a number of useful reviews on the El Cheapo Radios from China, so when he wrote “The Baofeng UV-B5 is close to perfect”, it caught my attention. I have a couple of the other radios from China that I blogged about here and here.
I ordered one of the radios from 409shop for $53 including shipping from Hong Kong, and it arrived a few days ago. After playing with it a bit, I downloaded the free programming software and loaded up a few frequencies. The software was a huge improvement over the crapware that came with the UV-5R…it installed easily and seems to work just fine.
I did an initial performance check with my HP 8920A RF Test Set and found the performance to be quite good:
VHF - transmit frequency error ~50 Hz transmit power 4.4W fm deviation ~4.5 to 5 kHz receive sensitivity ~0.2 uV UHF - transmit frequency error ~170 Hz transmit power 4.4 W fm deviation ~4.5 to 5 kHz receive sensitivity ~0.2 uV
I’ve noticed poor harmonic distortion on a few Baofeng radios, so I checked that out. On VHF, the harmonics are about -55 dBc, which is good. I did not check UHF but typically these radios have had better harmonic performance on the UHF band. Hans PD0AC reported similar measured results.
On the air testing resulted in excellent signal reports in terms of audio quality. The received audio is also loud and clear. The user manual is acceptable….mostly clear English but it does have some difficult-to-understand sentences here and there. Like the other radios from China, you’re really going to want to use the programming software to set things up. After that, the controls are quite usable.
Note that, unlike some of the other radios from China, the UV-B5 is not certified for Part 90 use. At least not yet.
A Yahoo group has sprung up to discuss this radio and share information, so check that out.
My overall assessment is that Baofeng has cleaned up the issues with the UV-5R (and don’t forget, I really like that radio!). The UV-B5 is a sweet little radio that will make a splash when it hits the US market.
73, Bob K0NR
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
I have been writing the FM column for CQ VHF Magazine for a number of years. I really enjoy doing it and I think the magazine is great. This quarterly magazine has special feature articles on VHF (and higher bands) and includes regular columns on satellites, space, radio direction finding, beginners guide, FM/repeaters, antennas and propagation.
If you are interested in ham radio above 50 MHz, check out this publication. Take a look at the current issue here.
Right now, there is a special offer on subscriptions.
73, Bob K0NR
I received a comment on my previous post on The Android HT, pointing to this Android mobile phone plus UHF transceiver: Runbo X5. This is not quite what I described as the Android HT but this device is certainly interesting just the same.
Runbo X5 Android Phone with UHF Radio
Looking around on the web, I found this set of specifications. The frequency range for the “walkie-talky” function is listed as 400 to 470 MHz. The power output is not specified, but the UHF range is listed as 5 km. Some of the photos show a rubber duck antenna while others do not, so I suspect that the UHF antenna is removable.
Of course, the Android HT that I described was amateur radio only, no mobile phone capability included.
73, Bob K0NR
8 Dec 2012 Update: I just noticed that PD0AC highlighted a similar product on his blog, the OutFone BD-351-A83.
You may recall the story about the origination of the Golf November Tango frequency of 146.55 MHz. Unfortunately, we have discovered an oversight in the selection of this important frequency.
On the 2 Meter band in the US and Canada, we have two different channel spacings in use. Some regions use a 15-KHz channel spacing while other regions use 20-kHz channels. All regions do use 146.52 MHz as the FM calling frequency, but the other channels are spaced based on local practice. The 20-kHz spaced band plan has simplex frequencies that include 146.52, 146.54, 146.56 and 146.58 MHz. With a 15 kHz spacing, the resulting simplex frequencies include 146.52, 146.535, 146.550, 146.565 and 146.580 MHz. Clearly, the existing frequency of 146.55 MHz was only compatible with the 15-kHz band plan.
An investigation is underway to determine who actually chose this frequency, so the responsible party can be held responsible. Unfortunately, no one seems to remember how the frequency was actually chosen, so the investigation continues. In the mean time, The Committee to Preserve Golf November Tango met and decided to launch a fast-track project to establish a new GNT frequency. If at all possible, this frequency must be compatible with both types of band plans, so that a North American GNT frequency can be restored to its former glory, while fully conforming to local VHF band plans.
After an intensive 18 month investigation, the team was unable to find such a frequency. Even though they met weekly, usually while partaking of copious quantities of Gin and Tonic, they were unable to find a solution. It looked like the entire enterprise might be in jeopardy. But late one night, one of the committee members blurted out “hey, why don’t we just use 146.52 MHz since I already have it programmed into my radio?” By some quirk of fate, the other committee members thought he said “146.58 MHz”, which, in fact, does fit both band plans. The GNT frequency was quickly designated as 146.58 MHz and the meeting was adjourned.
So remember, when you are on the beach and in the need of liquid refreshment, make a distress call on the GNT frequency of 146.58 MHz.
73, Bob K0NR
I’ve been writing a few articles for the HamRadioSchool.com web site during the past few months. Most of these are aimed at newly licensed Technicians but other radio amateurs may find them useful.
- A Half-Wave Antenna for Your 2 Meter Handheld Radio
- VHF FM Station At Home
- Yes, Band Plans Do Matter
I also put together a quick reference chart for Technician License Bands and Modes.
Check out the other content available on HamRadioSchool.com.
73, Bob K0NR
My article on the Android HT generated some interesting comments and ideas. Thanks so much! One of the main themes in the feedback is to have the radio be “faceless”, with the user interface done on a mobile device (i.e., smartphone or tablet). The mobile device would communicate to the transceiver via Bluetooth (or maybe WiFi). This approach has the advantage of separating the radio hardware (which probably doesn’t need to change very often) from the compute/display hardware (which is on a faster-paced technology path). I went ahead and hacked together a concept photo of such a device (click the photo to enlarge it). This device could interface with any mobile device that has a Bluetooth interface, so it would be independent of OS on the mobile device (yes, you could use your iPhone).
Such an approach opens up a variety of use models. Imagine sticking the transceiver in your backpack and using an app on your smartphone to enjoy QSOs when hiking. Alternatively, the radio could hang on your belt. At home, the radio could be left in some convenient location, connected to an external antenna on the roof and operated from the mobile device. (Low power Bluetooth is said to have a range of about 10 Meters.) These are just a few thoughts…I am sure you can think of others.
I would expect the original Android HT concept to be easier to use for casual operation, due to the All-In-One Design with dedicated hardware volume control, channel select and PTT switch. I am assuming those functions would be implemented in software in the faceless implementation, which would likely be less convenient. Most mobile devices have their own GPS system included, so that would mean one less thing that has to be in the radio.
The other idea that surfaced in the feedback is using Software Defined Radio (SDR) technology to implement the transceiver. This would provide a higher degree of flexibility in generating and decoding signals, enabling additional areas of innovation. That is a great idea and will require a whole ‘nuther line of thinking.
73, Bob K0NR
I’ve been watching all of the innovative work going on in the smartphone and tablet arena and wondering how we could get more of that going in ham radio. To be sure, there are always radio amateurs developing creative technology. Some examples are adaptations of D-STAR, IRLP, improvements on APRS and sound card modulation modes. However, amateur radio is missing a standardized platform for handheld communications. Such a radio platform could open up lots of software innovation in this space.
What I have in mind is a dualband (2M/70cm) handheld transceiver that is built on top of the Android operating system. (Sorry Apple Fan Boys, iOS is a non-starter based on Apple’s walled garden philosophy.) This radio would have some of the hardware features we now take for granted in smartphones: GPS, WiFi, USB, maybe even a camera. I’d also include APRS hardware built-in, similar to the Yaesu VX-8GR or the Kenwood TH-D72A. I’ve hacked together a concept photo shown on the left of this post (click to enlarge). We would probably want to maintain some of the most important direct hardware controls such as PTT, volume and channel select. The rest of the user interface would be done via a touchscreen display, where the power of the Android OS comes into play.
While this hardware configuration is exciting, the real power comes from having a software developers kit (SDK) with a stable Application Programming Interface (API). This would unleash the creativity of all those software-oriented hams out there and a plethora of apps would emerge. There are plenty of ham radio apps available on the Apple and Android platforms…it’s just they are missing the radio as part of the package. An obvious area for innovation would initially be in APRS or maybe D-STAR. We could actually have the equivalent of SMS text messaging on ham radio, backed up via the WiFi connection. (Yeah, this kind of exists already but it is really cumbersome to use due to the
braindead menu-driven user interfaces of current radios.) Just think how easy programming the radio would be with a touchscreen approach.
This is the type of product development that requires significant investment, but the technology is readily available. I suppose a garage shop operation could get this done but one of the big radio manufacturers could easily pull this off. Maybe one of those upstarts from China might want to take this on. Whoever does it, just send me $5 per unit and I’ll be happy :-).
That’s my best idea for this morning. What do you think?
73, Bob K0NR