Posts Tagged ‘vhf/uhf’

Magic Band Revealed

My ham radio pursuits have tended towards the VHF/UHF bands and the 6-meter band (50 MHz) has always been interesting to me. I like to think of 6 meters as a VHF band with some strong HF tendencies. Most of the time, propagation is local, certainly beyond line-of-sight, but also not long distance. When sporadic-e and F2 propagation show up, 6m tries its best to act like an HF band, skipping the signal off the ionosphere.

We call it the magic band because magical propagation occurs just when we least expect it. A more accurate name might be the fickle band because 6 meters provides short periods of random excitement followed by long periods of severe quiet. And that is why we like it so much.

Jim Wilson K5ND recently completed the third edition of the book Magic Band Revealed. Of course, I had to read it and I surely did enjoy this book. Jim hits all of the different operating and propagation modes that hams use on 50 MHz: sporadic-e, F2, TEP, meteor scatter, ionoscatter, etc. The WSJT-X modes have had a huge impact on what’s possible on the band, so Jim provides a good overview of the various options (FT8, FT4, MSK144, Q65). Jim also provides some helpful information on VHF contests and operating as a rover.

The best attribute of the book is that it is primarily written as a first-person account of K5ND’s operating experiences. Reading the book is just like having a friend tell you about what they’ve experienced on the band, along with some great operating tips. Great work, Jim!

The book is available as a free PDF download from Jim’s website or in print version via Amazon.
Go to https://k5nd.net/2023/11/magic-band-revealed/

73 Bob K0NR

The post Magic Band Revealed appeared first on The KØNR Radio Site.

Restricted putting up an antenna?

 Hide it in your holiday lights!

For all their supposed benefits, homeowner’s associations (HOAs) have a reputation of quickly turning otherwise quaint neighborhoods into a sort of Stanford prison experiment, as those who get even the slightest amount of power often abuse it. Arbitrary rules and enforcement abound about house color, landscaping, parking, and if you’ve ever operated a radio, antennas. While the FCC (at least as far as the US is concerned) does say that HOAs aren’t permitted to restrict the use of antennas, if you don’t want to get on anyone’s bad side you’ll want to put up an antenna like this one which is disguised as a set of HOA-friendly holiday lights.

For this build, a long wire is hidden along with a strand of otherwise plain-looking lights. While this might seem straightforward at first, there are a few things that need to be changed on the lighting string in order to make both the antenna and the disguise work. First, the leads on each bulb were removed to to prevent any coupling from the antenna into the lighting string. Clipping the leads turns what is essentially a long wire that might resonate with the antenna’s frequency into many short sections of wire which won’t have this problem. This also solves the problem of accidentally illuminating any bulbs when transmitting, as the RF energy from the antenna could otherwise transfer into the lighting string and draw attention from the aforementioned HOA.

Tests of this antenna seemed to show surprising promise while it was on the ground, but when the string and antenna was attached to the roof fascia the performance dropped slightly, presumably because of either the metal drip edge or the gutters. Still, the antenna’s creator [Bob] aka [HOA Ham] had excellent success with this, making clear contacts with other ham radio operators hundreds of miles away. We’ve shared another of [Bob]’s HOA-friendly builds below as well which hides the HF antenna in the roof’s ridge vent, and if you’re looking for other interesting antenna builds take a look at this one which uses a unique transformer to get wide-band performance out of an otherwise short HF antenna.

https://www.youtube.com/watch?v=4uG_D0bDGuI

Antenna Hidden In Holiday Lights Skirts HOA Rules | Hackaday

~ Hackaday



ARRL POTA Book

I was happy to contribute an article to the recent ARRL Parks On The Air (POTA) book. This piece is based on my Pikes Peak mountain topping article that appeared in the June 2023 issue of QST. This book is a collection of articles about POTA from 14 different authors, each writing about a different aspect of the program. The articles are all easy to read and generally provide a first-hand account of how the author has experienced POTA operating. There is plenty of beginner information and operating tips sprinkled throughout the book. More experienced POTA enthusiasts will probably pick up a few new ideas as well.

The Table of Contents below lists the articles and authors, giving you a good idea of the material covered. The meat of the book is only 118 pages long and it is quite easy to read.

My piece covered the triple activation I did from the summit of Pikes Peak, combining POTA, SOTA, and the June VHF Contest into one mountaintop adventure. For POTA, the park was the Pike National Forest (K-4404). I’ve done this type of combo activation in the past, sometimes just SOTA + POTA or just SOTA + VHF Contest. This time I did all three.

The book is available directly from the ARRL or from the usual book outlets such as Amazon.

73 Bob K0NR

The post ARRL POTA Book appeared first on The KØNR Radio Site.

Adios Symbol Rate Limit

The FCC will be voting on and will likely approve a Report and Order that eliminates the symbol rate restriction on HF data transmissions, replacing it with a bandwidth limit of 2.8 kHz. See FCC To Vote on Removing Symbol Rate Restrictions. The symbol rate limit of 300-baud is an obsolete way of limiting the signal bandwidth, created back when the data transmissions were predominately Frequency Shift Keying (FSK). It was a simple, practical way to regulate the bandwidth at that time but technology has moved on. The use of digital signal processing and efficient wireless encoding techniques require a better approach to bandwidth regulation.

A practical impact of this change is to allow higher speed protocols such as PACTOR-4 having a bandwidth of 2.4 kHz. I suspect we will see other protocols emerge that squeeze the best data rate out of the 2.8 kHz bandwidth.

Living in a Narrowband World

The FCC proposal implements a 2.8 kHz bandwidth limit on data emissions on the HF bands. Some folks have suggested a narrower bandwidth while others argue that wider bandwidth signals should be allowed. And some even think we should have no bandwidth limit at all.

The problem is that the amateur HF bands are not very wide. For example, the popular 20m band is 14.0 to 14.350 MHz, providing only 350 kHz of spectrum. Common practice on this and the other HF bands is to use modulation types that have bandwidths of 3 kHz or less. (Yeah, AM signals are twice that wide, at 6 KHz, a topic for another day.) Of course, CW and some of the data modes are much narrower than 3 kHz. But the general approach to regulating HF is to allow many narrowband signals on the band. Limiting HF data transmissions to 2.8 kHz bandwidth is consistent with existing practice while still allowing for innovation and experimentation.

VHF/UHF Bandwidth Limits

The FCC also plans to issue a Further Notice of Proposed Rulemaking (FNPR) that:

  • Proposes to remove the baud rate limitation in the 2200 meter and 630 meter bands, which the Commission allocated for amateur radio use after it released the Notice of Proposed Rulemaking in 2016.
  • Proposes to remove the baud rate limitation in the VHF and UHF bands.
  • Seeks comment on the appropriate bandwidth limitation for the 2200 meter band, the 630 meter band, and the VHF/UHF bands.

I won’t comment on the 2200 meter and 630 meter bands. The FCC proposes to remove the symbol rate limit on the VHF and UHF bands and asks what bandwidth limit is appropriate. The current bandwidth limits are 20 kHz for the 6m and 2m bands, 100 kHz for the 1.25m and 70 cm bands, and the FCC seems fine leaving these the same. Authorized emission types are listed in FCC Part 97.305.

With 4 MHz of spectrum, the 2m band is much wider than any of the HF bands. It might be tempting to conclude that there is plenty of room for wideband signals on this band. Many hams think 2 meters is just used for FM simplex and repeaters but a closer look reveals that it supports many diverse modes: weak-signal SSB/CW, meteor scatter, EME, FM simplex, FM repeaters, digital voice modes (D-STAR, DMR, Fusion), satellites, and more. The 20-kHz limit seems appropriate, as it roughly matches the bandwidth of the most common (FM) voice signals on that band. It is not an appropriate band for trying out wider bandwidth signals.

The 6m band should probably keep the same 20-kHz limit. (I don’t think there is a compelling reason to change it.) The 1.25m band already allows 100-kHz bandwidth data signals, which some radio amateurs have used for higher-speed data links (still not what I would call wideband).

The 70 cm band is much bigger (420 MHz to 450 MHz) and could accommodate some wider bandwidth signals. Perhaps the existing 100-kHz limit should be increased? Keep in mind that fast-scan ATV is allowed on this band with a bandwidth of 6 MHz. Maybe we can make some room for a few larger bandwidth data channels, to encourage innovation and experimentation.

The bands above 70 cm have no bandwidth limit other than the signal must stay within the designated ham band. It has been this way for a long time, without causing any issues (that I know of).

Conclusion

The FCC’s proposal makes a lot of sense and it is long overdue. Frankly, it is a bit of an embarrassment that it has taken so long.

Better late than never.

73 Bob K0NR

The post Adios Symbol Rate Limit appeared first on The KØNR Radio Site.

Another Continental Divide Summit (W0C/RG-169)

A view of the W0C/RG-169 summit from the Continental Divide Trail. Look closely to see the game trail heading up to the right towards the saddle.

Lobo Overlook is an excellent summit and tourist spot near Wolf Creek Pass, one of the most scenic passes in Colorado. I’ve been up there for VHF contests and other mountaintop operations and initially thought it might be a SOTA summit. No such luck, as it is superseded by a higher summit nearby (W0C/RG-169). Lobo Overlook is accessed via an easy 3-mile gravel road just off the pass. The road leads to two small loops at the top, one of which is the actual Lobo Overlook while the other goes to an obvious radio site. The trail to RG-169 is best accessed from the radio site, so we parked there. Wolf Creek Pass and Lobo Overlook sit right on the Continental Divide and the Continental Divide Trail (CDT) passes through here just a bit to the west.

The Lobo Overlook road starts slightly east of Wolf Creek Pass.

Lobo Peak

This unnamed summit is listed as 11820 in the SOTA database. However, Lists of John (which was used to create the W0C SOTA database) shows this summit as 11831. My topo map seems to agree with 11831, so this might be an error. Of course, such a cool summit near the CDT deserves a name, so Joyce/K0JJW and I decided to call it Lobo Peak, for obvious reasons. (I looked for an existing nearby Lobo Peak and did not find one.)

Near the radio site, we started at the marked trailhead and headed west on Lobo Trail (878), actually going downhill to intersect the CDT about a half mile down the trail. At the trailhead, it was not obvious which summit we were headed to and it might not even be visible at that point. The summit did reveal itself as we headed down the CDT (see first photo above). We followed the CDT to a visible game trail that takes off steeply to the right (lat/lon 37.49765, -106.81515). There are several game trails that split off, heading up towards the saddle to the left of the summit and we stayed on the most established one. We set up our station within the activation zone just below the actual summit, avoiding the rock scrambling to get to the top.

The trail from Lobo Overlook to RG-169 mostly follows the Continental Divide Trail.

The one-way distance on the trail is 1.2 miles with an up-and-down profile. Lobo Overlook is only slightly lower in elevation from “Lobo Peak”. The trail starts at about 11,770 feet, descending to a low point of 11,500 and back up to 11,800 at the summit. So that produces a net ascent of about 300 feet, maybe more, one way. Of course, you get to repeat this on the way back.

The sign at the trailhead calls this Lobo Pass.

SOTA and POTA Activations

Once in the activation zone, we deployed the IC-705 on 2m FM, driving the 3-element Yagi antenna. We worked Travis/KB9LMJ on 146.52 MHz, who was mobile in Pagosa Springs. Further calling on 2m FM did not yield any contacts, but K0JJW and I did work each other on VHF/UHF. We had anticipated that this might be a tough place to activate on VHF, so we brought along the HF gear and set up an EndFed Halfwave antenna for 20m. Propagation was good and we soon worked 11 stations on 20m SSB.

This summit sits right on the dividing line between the Rio Grande National Forest and the San Juan National Forest, both valid for Parks On The Air (POTA). We opted to operate from the Rio Grande side (K-4405) because that was a new one for both of us.

This is the radio site as seen when you return from the summit, so no excuse for getting lost.

Continental Divide Trail

I’ve hiked sections of the Continental Divide Trail before, including some pre-SOTA backpack trips with Denny/KB9DPF. It is a great trail because it runs along the backbone of the Rocky Mountains. It is often accessible via roads to high mountain passes. (Another example is Wander Ridge, just off Cottonwood Pass.) Once you hop onto the CDT, you are hiking an established trail that is literally on top of the world.

This is an excellent, easy-to-access summit in the Wolf Creek Pass area. So if you are in the area, this might be one to activate. The road to Lobo Overlook is closed during the winter.

73 Bob K0NR

The post Another Continental Divide Summit (W0C/RG-169) appeared first on The KØNR Radio Site.

Argentine Pass and Argentine Peak

Argentine Peak (W0C/SR-019) is a high 13er (13,738 ft) in the Sawatch Range of the Rocky Mountains. I had my eye on this summit for a Summits On The Air (SOTA) activation for quite some time now. This summit is a short distance from Argentine Pass, which is the fourth-highest road in Colorado at 13,207 feet. A non-radio goal I have is to drive the Jeep up the twenty highest roads in Colorado, so Argentine Pass is on that list. Not only that, Argentine Peak sits on the Continental Divide, separating the Arapaho National Forest and the White River National Forest, so it can also be activated for Parks On The Air (POTA).

Bob/K0NR and Joyce/K0JJW on the way up Argentine Peak in the background.

So the plan emerged: Joyce/K0JJW and I would take the Jeep to Argentine Pass and then climb up to Argentine Peak for a SOTA and POTA activation. The road is usually blocked by snow for much of the summer, making it a late summer/early fall adventure. Somehow September slipped away and it is now October, but fortunately, the road is still open. Note that the more common way to hike Argentine Pass is from Silver Dollar Lake trailhead (see KX0R trip report).

The 4WD route is shown above in orange, starting out as FS 248.1 leaving Guanella Pass Road.

The Road

The 4WD route starts with FS 248.1 as it leaves Guanella Pass Road, about 3 miles south of Georgetown, CO (see map above). The forest service road takes off at a point where the Guanella Pass Road takes a very sharp bend. You should have a good topo map to guide you on this route as there are quite a few roads in the area. In general, you follow FS 248.1 which has some subvariants such as 248.1B and 248.1K. The exact choice of roads is not critical but, eventually, you need to get on FS 724.1 which sports a few wide and steep switchbacks up to Argentine Pass. The one-way distance is 9 miles and it took us about 1.5 hours to make the drive.

This road and route is considered moderate 4WD and FS 248.1 provides a good taste of that right after you leave the paved road. Many other sections of the road are easy 4WD but there are some challenging spots along the way. This is a real 4WD road, so you’ll need a decent high-clearance 4WD vehicle in the class of a Wrangler, Bronco, 4Runner, etc. We drove a stock Jeep Wrangler and had no trouble. However, at one spot, the wheel placement was very critical, so Joyce spotted me as I drove through it. Not that difficult…unless you screw it up.

The Climb

As shown below, the climbing route up Argentine Peak (blue line) follows the Continental Divide ridge line as it heads south from Argentine Pass. The road up Argentine Pass ends kind of high in the pass, so at first, we were walking downhill. A faint trail follows the top of the ridge but fades out in many places. Looking at the topo map, I underestimated how much up and down there would be on the ridge but it was not too difficult.

The route to Argentine Peak follows the Continental Divide ridge line from Argentine Pass.

The hike is about 1 mile with 650 feet vertical (one-way). We had fantastic weather in October: sunny, with temperatures in the 40’s F and some light wind (10 to 15 mph). This is one of those top-of-the-world hiking experiences, right along the Continental Divide.

Joyce/K0JJW on the summit of Argentine Peak.

As you can see from the photos, there were some patches of snow on the ground, but it was not an issue for hiking. A real Mountain Goat (not a SOTA Mountain Goat) wandered by and paid us a visit.

This mountain goat wandered by while we were on the summit.We used our standard 2m/70cm FM station: Yaesu FT-90 running 30 watts to a 3-element Yagi for 2 meters or a 7-element Yagi for 70 cm. We worked stations mostly on 146.52 MHz FM and a few on 446.0 MHz. With downtown Denver about 45 miles away, we easily worked stations in the greater Denver area. We were also successful working stations out to 60 or 70 miles, often with good signal reports in both directions. We both made 20 QSOs using VHF/UHF.

For POTA, we were right on the dividing line between White River NF and Arapaho NF but needed to choose one for our activation. We had previously activated Arapaho, so we chose to operate from White River NF on this trip (K-4410) which is a new park for us.

Summary

We had an absolute blast on this activation. I think it was the combination of a Jeep trip, hiking, SOTA, and POTA all wrapped into one adventure that made it so good. As a bonus, we had excellent weather and a visit by the mountain goat!

73 Bob K0NR

The post Argentine Pass and Argentine Peak appeared first on The KØNR Radio Site.

Why Use FT8 For POTA?

The FT8 station consists of an iPad, Icom IC-705, MFJ-902 tuner, a battery pack, and one of many wire antennas.

In a previous post, I described getting the IC-705 set up for FT8 using the SDR-Control app on an iPad. My objective was to have a portable FT8 station for use during SOTA and POTA activations.

To save time, let me get this out of the way:

Yes, I do know that making contacts via FT8 is not as personal and may not be as much fun as running a pileup on SSB or CW. Still, it is Real Ham Radio and enjoyable in a different way.

I’ve used this station on multiple activations now but I have to admit that these have been mostly for POTA. It seems that whenever I get on top of a SOTA summit, I tend to focus on making VHF contacts which consumes the available time and the HF gear remains stashed way in my pack. This is more about my operating habits than anything else. Looking at spots though, there is a lot of FT8 on POTA and not nearly as much on SOTA. The SOTA crowd tends to have a lot of traditional CW enthusiasts and maybe POTA has fewer of them. Also, SOTA operating is usually backpack portable so carrying a compute device for FT8 may be considered an unnecessary hassle. POTA stations are often in or near a vehicle, so station size/weight is less of a concern.

For POTA, I make sure my activation is posted at pota.app, indicating the park number I am activating. When calling CQ, I modify the standard FT8 text to be “CQ POTA” to indicate that I am doing an activation. When my signal is detected by the Reverse Beacon Network (RBN), a spot is created that shows me doing a POTA activation from that park. Pretty cool. If I have an internet connection, I monitor my spots using the Ham Alert app. This provides useful feedback about where my signal is showing up around the world.

But what are the main reasons that FT8 is useful for POTA?

FT8 is popular

In case you haven’t noticed, FT8 has emerged from being just a niche activity to now being very popular on most ham bands. At times this can be a problem with the standard FT8 frequency slice being overloaded with signals. There is a lot of FT8 activity on the bands, for general ham use and SOTA/POTA.

FT8 works well with low power

FT8 and the other WSJT-X modes are designed to work well with weak signals, so they are a great match for low-power operation. Of course, QRP power levels are very common for backpack portable activations, mostly due to the limitations of carrying a reasonable-size battery.

FT8 signals are spotted on RBN

As mentioned earlier, FT8 signals are picked up and spotted by RBN. For better or worse, people have come to rely on spotting for many types of ham radio operating. When on a SOTA or POTA activation, you really want to be spotted as such. For phone activations, I usually do that with a smartphone but that requires some extra effort and a mobile phone connection. FT8 and RBN take care of that for you.

FT8 logging is automated

The various FT8 software applications automatically log the QSO information, which means it is easy and less error-prone. After the activation, I just pull up the ADIF log file, check it for obvious errors, add in the SOTA/POTA info, and submit it to the appropriate websites.

FT8 is campsite friendly

This last one may be a bit subtle but I’ve found FT8 to be campsite friendly. By that, I mean I can get on the air at any time (early, late or at nap time) and not disturb anyone else. (On SSB, I would likely be enthusiastically yelling into the microphone trying to work a pileup.) Besides the audio noise factor, FT8 operation allows for multitasking. I can converse with my fellow campers while still keeping up with the FT8 flow. Alternatively, I can cook dinner, make a fire, or pack my backpack while the FT8 QSOs roll in. This may sound a little bit like cheating but, hey, whatever works.

Wrap Up

So clearly, I’ve been having fun with FT8 for POTA. I consider it to be another tool in the toolkit. There are times when I will make good use of it but there will also be times to use other modes.

73 Bob K0NR

The post Why Use FT8 For POTA? appeared first on The KØNR Radio Site.


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