Digital Voice at Pacificon

Last weekend, I had the privilege of attending the Pacificon amateur radio convention in Santa Clara, something I have been trying to do for several years now. It is a great event, with good technical programs and a super venue.

The most interesting presentation I saw was the one on digital voice (DV) technology by Bruce Perens K6BP. The presentation was mostly about the digital voice known as FreeDV,  an open source approach to DV that uses the Codec 2 voice codec for digitally processing/compressing speech.

K6BP photo

Bruce Perens K6BP talking about FreeDV

I won’t cover all of the technical details here but you can follow the links above to go deeper on the topic. The initial FreeDV efforts are focused on the HF bands, using the sound card plus computer approach to implementing DV. This is a good approach since it is a relatively easy way to adopt this technology. (Compare this to VHF/UHF where you need to solve the repeater infrastructure problem to make progress.) FreeDV operates with a bandwidth of  1.25 kHz, narrower that the standard 3 kHz or so SSB signal. FreeDV also has the benefit of degrading gracefully as the  signal-to-noise ratio is decreased, with less of a digital dropoff that we see with D-STAR and other DV technologies.

Like many hams, Bruce pointed out the concerns and limitations of the proprietary AMBE chip used in D-STAR, DMR and now the new Yaesu DV system. I totally get this point and support the idea of a an open source codec. On the other hand, this work is coming more than a decade later than the creation of D-STAR. I like to refer to this phenomenon as “our ideas are better than their products.”

Bruce introduced Chris Testa KB2BMH to talk about the “HT of the Future”. This is a handheld transceiver implemented using Software Defined Radio (SDR) and inspirations from the world of smartphones. As Bruce said, “Why isn’t your HT as smart as your smart phone?” This is similar to the Android HT idea that I blogged about a while back. See Chris’s blog and this HamRadioNow video for more information.

Another presentation that I attended was about D-STAR with several speakers, including Robin AA4RC. The innovation continues to happen in the D-STAR world with a strong theme of using Raspberry Pi computers to create D-STAR hotspots and repeaters. Robin described the “DV Pi” being developed…a DVAP-like daughter board that plugs into a Raspberry Pi. Jim Moen K6JM talked about the many ways you can implement a D-STAR Hotspot. For more info on that see his D-STAR Hotspot page.

There’s much innovation happening in the area of Digital Voice. It got me thinking about it again so I dug out my ICOM D-STAR HT and put my DVAP back on the air.

73, Bob K0NR

A Classic SOTA Hike: Midland Hill (W0C/SP-117)

Today, Joyce K0JJW and I decided to hike Midland Hill (W0C/SP-117) near Buena Vista, CO (otherwise known as “BV”) and do a SOTA activation on VHF. I call this a “classic SOTA hike” because it is a real hike that requires some exertion, a well-maintained trail to the summit and some great views at the top. By my GPS, it was 2.4 miles one way, with 1600 feet elevation gain.

This hike starts at the trailhead on the east side of BV, where a footbridge crosses the Arkansas River. The SummitPost trail description is very helpful, so be sure to check it out. I checked quite a few topo maps of the area and most of them do not show the trails accurately. I found them more confusing that helpful. I’ve included my GPS track on the map below.

Midland Hill route

GPS track for Midland Hill

We started at the trailhead, immediately crossing the footbridge to the east side of the river. Then we followed the Midland Bike Trail which parallels the river. Very soon after the bridge, there is a trail leading off to the left (east) uphill that is tempting but we stayed on the main trail that parallels the river. At about 0.5 miles in, we crossed County Road 304 (38.843508 deg N, 106.112297 deg W) onto the clearly marked 6032 trail, which goes up to Midland Hill. Just follow the trail and do not turn onto 6032A trail as it goes off to the left.

If you are pressed for time, you can start the hike where 6032 intersects CR 304, but that only saves 0.5 miles. You’ll miss the bridge and great views of the Arkansas River.

Bob K0NR on the trail

Bob K0NR on the trail

Once we reached the summit, I set up on 146.52 MHz using my VX-8G connected to the 2M Arrow Yagi. Joyce stayed back outside of the activation zone, so I worked her as soon as I made the summit. Then Walt WZ0N came up on frequency and gave me a second contact.  I contacted a couple of mobile stations: Ryan KD7OHA on Highway 50 near Texas Creek and Bud NP2CT on Highway 285. Other contacts where with some of the local hams: N0OFQ near Nathrop, Jerry N0VXE and Skip W9GYA near Salida. Not bad for a Monday afternoon in the mountains. Thanks, guys, for the contacts!

Lately, some of the SOTA hikes I’ve done have involved bushwacking up the side of a steep hill to get to the summit. It was great to have a real trail this time. The 1600 vertical feet did get me huffing and puffing but that’s part of the experience. I highly recommend this summit!

73, Bob K0NR

How To Do a SOTA Activation On Pikes Peak

Perhaps this should be called The Slacker’s Guide to Activating Pikes Peak since I am going to describe the easy way to do a Summits On The Air (SOTA) activation on America’s Mountain. If you plan to hike up, you have my complete support but this post is not meant for you.

Pikes Peak 2

Pikes Peak (W0C/FR-004) is about 10 miles straight west of downtown Colorado Springs. See the Pikes Peak web site for useful tourist information. At an elevation of 14,115 feet, the mountain towers over Colorado Springs and the other front range cities. (You may see the elevation listed as 14,110 but it was revised upward in 2002 by the USGS.) This means that is has an excellent radio horizon to large populated areas. On VHF, it is common to work stations in Kansas, Nebraska, Wyoming and New Mexico. See VHF Distance From Pikes Peak  and Pikes Peak to Mt Sneffels. On HF, you’ll do even better.

Pikes Peak map

Access to the summit has three options: hike up, drive up via the Pikes Peak Highway or ride the Pikes Peak Cog Railway. Most people will probably choose the highway since the cog rail only gives you 30 to 40 minutes on the summit. (Normally, you return on the same train that takes you to the top. You can try to schedule two one-way trips but that is a challenge.)

The highway is at a well-marked exit off Highway 24, west of Colorado Springs. There is a “toll” to use the highway (~$12 per person, check the Pikes Peak Highway web site for the latest information and a $2 discount coupon.) The road is now paved all of the way to the top and is usually in good shape. The only caution on driving up is that some people get freaked out by sections of the road that have steep drop-offs without guard rails. It is very safe but I know some folks just can’t handle it. The main caution driving down is to use low gear and stay off your brakes. There are plenty of signs reminding you to do this and during the summer there is a brake check station at Glen Cove where the rangers check the temperature of your brakes.

It takes about an hour to drive to the summit, assuming you don’t dawdle. It is best to drive up during the morning and avoid the afternoon thunderstorms. (Check this web site for when the gate opens, usually 7:30 am in the summer.) Once you get to the summit, you’ll find a large circular parking area, the summit house and a few other buildings. The W0C Association Reference Manual (the SOTA rules for Colorado) used to suggest a “qualifying hike” of 100 vertical feet but this item has been removed from the manual. If you decide to do such a hike, I suggest you proceed down Barr Trail which is the main hiking trail coming up from the east side of the peak. Do not try to walk along the road, as the rangers will stop you. The trail starts on the east side of the summit house (towards Colorado Springs) and is marked with a sign. You have to cross over the cog rail tracks to get to it. (Please try to avoid getting run over by the train as it scares the tourists and makes a mess.)

The summit of Pikes is broad, flat and rocky, so pick out a spot away from the buildings for your SOTA adventure. There are quite a few radio transmitters on the peak so expect some interference. Since this is way above treeline, your antennas will have to be self supporting. For VHF, giving a call on 146.52 MHz FM will usually get you a few contacts and sometimes a bit of a pileup. Be aware that on top of Pikes you are hearing everyone but they can’t always hear each other. It can get confusing. Some other VHF simplex frequencies worth trying are 147.42 MHz (The Colorado 14er frequency) and  146.46 MHz (a local 2M hangout frequency). If you have 2m SSB, call on 144.200 MHz USB.  On the HF bands, pray for good ionospheric conditions and do your normal SOTA thing.

Your body and your brain will likely be moving a little slower at 14,000 feet due to the lack of oxygen. Don’t be surprised if you have trouble deciphering and logging callsigns. Take it slow and monitor your physical condition on the peak.

Bring warm, layered clothes even in the summer, since Pikes Peak can have arctic conditions any time of the year. Keep a close eye on the weather since thunderstorms are quite common during the summer months. Lightning is a very real danger, so abandon the peak before the storms arrive.

73, Bob K0NR

Resources

SOTAwatch web site
W0C SOTA Website
Pikes Peak Tourist Information
Pikes Peak (W0C/FR-004) SOTA Page
Pikes Peak Web Cam
Pikes Peak Highway Information 

A Soggy Mount Herman SOTA Activation (W0C/FR-063)

Although I’ve operated a number of VHF contests from the summit of Mount Herman, I had not yet activated it as a Summits On The Air (SOTA) peak. Mount Herman is a 9063 foot mountain just to the west of Monument, Colorado, pretty much in “my back yard.” Steve WG0AT did the first SOTA activation of Mount Herman, back in May 2010, chronicled here in one of his famous videos.  There is a sometimes rough Forest Service Road 320 that leads to the trailhead, then it’s a little more than a one mile hike to the top with 1000 feet of elevation gain. I call it a tourist hike, since it has just enough challenge to make it feel like a climb and there’s a great view at the top. At least on most days.

Mt Herman map

I was not expecting much of a view today since low rain clouds were dominating the sky. I was just hoping I would not get completely drenched by rain. The weather was definitely marginal but from my house I saw the clouds lift a bit, so I thought it was worth a try. The ARRL September VHF Contest is also this weekend, so it was a great combo opportunity: SOTA + VHF Contest.

K0NR HT in the rain

I hopped in the Jeep and quickly made the drive to the trailhead. Then I scooted on up the trail, making it to the summit in about 30 minutes. Just as I reached the summit, the rain really kicked in. I set my gear down under a tree, got out my HT, attached the 1/2-wave antenna and started calling on 147.42 MHz. I wanted to bag my four SOTA qualifying contacts in case the weather turned worse. I quickly worked Frank K0JQZ and Steve WG0AT. Then George AB0YM, operating as a rover in the VHF contest called me from grid DM78, so I worked him as well.

I had my trusty Arrow Yagi antenna with me but I didn’t want to bother with assembling it in the rain. I got out the FT-817, put a vertical antenna on it and called on 144.200 USB. I found stations working the VHF contest and completed QSOs with them: WB0RRU and K3ILC.

The rain intensified so I abandoned the summit and headed back down. All in all, it was not a great hike but I was successful in activating Mount Herman.

73, Bob K0NR

Two SOTA Activations: W0C/SP-099 and SP-115

Bald Mountain (W0/SP-115)

Bald Mountain (W0/SP-115)

Lately, I have been focusing on activating the SOTA (Summits On The Air) peaks near our cabin in the mountains. The basic idea is to identify a SOTA summit, hike to the top and make a few contacts on VHF. On Friday, my spousal unit (Joyce, K0JJW) and I decided to head out to an unnamed peak (W0C/SP-099), southeast of Buena Vista, CO.  By no coincidence, this summit had not been activated yet, so we’d get the esteemed honor and glory of being the first.

For lesser known summits, a bit of research is required to figure out the route. My first stop is to check the SOTA database for basic information on the summit. I’ll usually have to dig further using ListsOfJohn and SummitPost. ListsOfJohn is an incredible database of topographical information, listing every summit along with information such as elevation, lat/lon, rise, etc. (The Colorado SOTA information was gleaned from ListsOfJohn.) SummitPost will usually have more detailed information on a summit but only for the more popular ones. The  SOTA Mapping Project is another excellent resource with very useful interactive topo maps. And, of course, I also dig out the US Forest Service map for the area, which often gives the best view of access roads.

We drove the Jeep to within a mile of the summit and started hiking up. I posted our route information on ListsOfJohn, so take a look there for that information. The summit is unnamed, so it is referred to by its elevation: 10123. I had my Yaesu VX-8GR burping out APRS packets which were plotted on aprs.fi when we reached the summit.APRS K0NR-7

When we reached the summit, I spotted myself on the SOTAWatch web site using the SOTA Goat app on my smartphone. More importantly, the night before the hike, I sent an email to some of the radio amateurs that were likely to be within VHF range. That paid off and I worked Jim KD0MRC, Walt WZ0N and John K3NOQ on 146.52 MHz FM. Jim was hiking to Harvard Lakes above 10,000 feet, so it was special to be able to contact him on the trail. A little later, I caught KV4AL who was mobile near the top of Mount Evans. While only one contact is required to “activate” a summit, four contacts are needed to earn SOTA points, so I was happy to make these four QSOs. My gear was a Yaesu FT-60 driving a 3-element Arrow yagi antenna.

In addition, Joyce and I generally work each other on the SOTA the summit. The SOTA rules say that “QSOs with others within the same Activation Zone do not count towards the QSO total” which means that one of us needs to hike down a bit to get outside of the activation zone (75 feet vertical feet from the summit). We take turns doing this so that each of us activates the summit and makes a contact with the summit.

We took a round about path back to the Jeep and headed for Bald Mountain. At this point, we were both very tired and the thunderstorms were moving in. We decided to at least check out the access to Bald Mountain (WoC/SP-115) even if we didn’t climb it that day. It turns out that there is a 4WD road that goes to the top of the mountain, so we drove to the summit. The road is very rough in a few spots but the Jeep handled it nicely. At the top, we hiked back down a bit to meet the non-motorized ascent requirement for SOTA. We also did our “work each other” technique while on the mountain so that we each had a contact. I was not able to raise anyone on 146.52 MHz but I did catch Carl K5UK on the 146.745 MHz repeater and worked him on simplex. By this time, it was raining with lightning getting closer, so we abandoned the summit and headed back to the cabin.

Thanks to the guys that took the time to contact us on the two summits.

73, Bob K0NR

Summits On The Air (W0C/SP-112) – Castle Rock

There is a very jagged peak just east of Buena Vista, CO called Castle Rock (not to be confused with the city by the same name). I knew this was a SOTA summit (W0C/SP-112) and I had my eye on it for a while now. It is extremely rocky and jagged near its summit, so I was not sure if it could be ascended without a technical climb. A little research revealed that it was climbable but quite steep near the top. SummitPost.org has a good description of how to ascend this peak.

Castle Rock

Castle Rock

My hiking partner and wife, Joyce K0JJW, joined me on the climb. We managed to get off the preferred route and got into some very steep rock scrambling. Good judgment prevailed and we regrouped and found a more reasonable path but probably cost us an extra hour of hiking. As advertised, it did get very steep at the top. (Study the SummitPost information more carefully than I did.)

Assembling the Arrow 2-Meter antenna

Assembling the Arrow 2-Meter antenna

Recently, I picked up an Arrow 3-element Yagi antenna for 2 Meters  (Model 146-3). This antenna can be dismantled and carried inside a reasonable size daypack (or strapped on externally). The boom has two threaded holes for mounting the antenna on a camera tripod. I used a MountainSmith trekking pole that can double as a camera monopod and mounted the antenna on it.

Operating with the Arrow antenna mounted on the trekking pole

Operating with the Arrow antenna mounted on the trekking pole

For this SOTA activation, I kept it simple and just used my Yaesu FT-60 to work 2 Meter FM. Accordingly, I configured the Yagi antenna for vertical polarization. (There are two mounting holes on the boom, so you can choose vertical or horizontal orientation.)

The trekking pole is not self-supporting and does not provide much additional antenna height but it makes the antenna a lot easier to point for extended periods of time. I like to use a trekking pole for hiking, so this is a good way to get a little extra utility out of it. I am pleased with how this antenna system performed and will use it again.

73, Bob K0NR

This Spewed Out of the Internet #25

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

Get Ready For Field Day

2013FieldDayLogoWebAttention all radio amateurs, this weekend is ARRL Field Day! Don’t forget to get on the air.

Field Day is a flexible event, so it can be anything you want it to be: camping weekend, stay at home, participate with your club, go mobile, whatever you desire. Remember to season to taste.

One more thing: Field Day is not a contest. But you can still keep score.

Oh, remember that the national simplex FM calling frequency of 146.52 MHz should not be used for making Field Day contacts. Like all contests…wait Field Day is not a contest. Whatever.

– 73, Bob K0NR

 

The New VHF Contest Categories

arrlnewlogo-transThe 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

June VHF radio gear

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.
K0NR CQ WW VHF

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

when-all-else-fails-logo“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.

Escape alternator noise 12V at radio - higher revs

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.

Escape alternator noise 12V at radio - at 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.

Escape alternator noise 12V - new alternator 2

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 (W0C/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.

K0NR on Aspen Ridge IMG_1553

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, W0C/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.

K0NR on Aspen Ridge IMG_1557

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

baofeng uv-5raIn 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.

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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).

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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

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

This Interference Seems to Follow Me Everywhere

USB chargerA 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

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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

Bdale KB0G Makes Stuff!

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