Archive for category VHF
The New VHF Contest Categories
The results are in from the 2013 ARRL January VHF Contest, which includes the new Single Operator 3 Band and Single Operator FM Only entry categories.
There were 77 entries in the SO3B category, with Rich KV2R having the high score: 6368 pts. Breaking his contacts out by band reveals 50MHz:92 QSOs/18 Grids; 144MHz:83 QSOs/12 Grids; 432MHz:12 QSOs/2 Grids. I operated in the same category but with a lower score: 1311, broken out by band this way: 50MHz:27/12; 144MHz:24/8; 432MHz:3/3. As I recall, 50 MHz propagation was not really that great, which is going to be the major swing factor for scores in the SO3B category. Scanning through the top SO3B entries reveals a relatively consistent pattern of 50 MHz having the highest number of QSOs, with 144 MHz in the same ballpark and 432 MHz significantly lower in count.
There were only 23 entries in the SOFM category, which is probably not a big surprise. While there are pockets of FM activity during VHF contests, historically the fun mode has not been used that much for contesting. The whole idea behind SOFM is to open up contesting to the FM operator. It remains to be seen how effective this will be but if it does catch on, it will take some time to build momentum. Ev W2EV had the high score of 1080 in the FM category, broken out by band here: 50MHz:19 QSOs/4 Grids; 144MHz:27 QSOs/4 Grids; 222MHz:5 QSOs/4 Grids; 432MHz:8 QSOs/3 Grids. W2EV’s score shows just a few grids per band, indicating shorter distance contacts overall. With only 4 grids on 50 MHz, he probably did not benefit from sporadic-e propagation on that band. The second place entry was from Erich KC9CUK who only worked the 2 Meter band, producing a score of 441 with 63 QSOs and 7 grids. The remaining entries had less than 30 QSOs. Almost everyone had contacts on 144 MHz but the usage of the other bands varied significantly.
I have always been most interested in operating 50 MHz and 144 MHz, sometimes adding in 222 MHz and 432 MHz, so I find SO3B a nice addition to the contest. In this category, I get to operate my favorite bands but my score does not get compared with the guys that have built stations that do 50 MHz through light. I suspect there are plenty of other VHF contesters in this same boat.
I find the FM category very interesting, as I have always tried to encourage FM operating during the contests. Clearly, FM is less effective than SSB and CW, particularly when the signals are weak. I don’t know whether this category will attract new operators or not to VHF contests. FM operation needs to hit critical mass because activity generates activity. That is, if you are the only FM contester in your area, its going to be frustrating. Of course, it will help if the established SSB stations make it a point to also work FM.
Oh, one more thing… we still need to get rid of the rule that says no contacts on 146.52 MHz. This rule is counterproductive. Every time I talk with an FM op about “getting on during the contest” they say “OK, so I should just call on five two, right?” I have to explain that calling on the calling frequency is not allowed during the contest (uh, that’s only for FM, you see) and their minds start to wander to topics that make more logical sense.
73, Bob K0NR
K0NR June VHF Contest
My June VHF Contest operation was at the cabin DM78av, operating in the new 3-band single-op category this year. Usually, I have been a two-band guy just focusing on 2M and 6M. I drug along my 432 MHz antenna and drove it with 50W from my FT-847, picking up a few more QSOs that way.
My score is down from the previous two years, which I think relates to the 50 MHz propagation. I subscribe to the theory that any June contest that has any sporadic-e is a success, so I am not going to complain. However, it did seem like I spend more time digging weak signals out of the noise on 6 Meters this year. It was often just barely open and the QSO rate was slow.
Best DX was XE2WK in EL03 on 50 MHz.
73, Bob K0NR
2013 ARRL June QSO Party K0NR DM78
Band QSOs X pt = QSO pts. X Grids = Points --------------------------------------------------------------- 50 320 1 320 112 35840 144 34 1 34 11 374 432 13 2 26 6 156 --------------------------------------------------------------- TOTALS 367 380 129 49020
Claimed score = 49020
CQ WW VHF Contest Certificate
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
A Simple Wilderness Protocol: 146.52 MHz
“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.
The Mysterious Case of Alternator Noise
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
SOTA Activation: Aspen Ridge (W0/SP-084)
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
Checking Out A Baofeng UV-5RA
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
FCC Grants Waiver on TDMA
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
This Interference Seems to Follow Me Everywhere
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
GNT Shirts Now Available
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
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