Posts Tagged ‘vhf/uhf’

About That UHF Connector

I caused a minor kerfuffle on Twitter recently, when I posted this:

This connector, properly called a PL-259, is the most common RF connector for ham radio use. The female counterpart is called the SO-239 connector. While these connectors are often “UHF” connectors, they actually don’t perform very well at those frequencies (300 to 3000 MHz). So I feel justified in disparaging that name.

The tweet generated a large number of replies, mostly in support of my anti-UHF-naming sentiment. It seems that other highly-educated and thoughtful radio amateurs agree with me. (It seems that the wise hams out there always agree with me.) You should be able to view the thread here: https://twitter.com/K0NR/status/1653575723838492672

Some people pushed back on the anti-UHF sentiment, usually saying that it is the common name for this connecter. A few folks pointed out that Amphenol calls these things “UHF Connectors”, which did surprise me. Who am I to disagree with this manufacturer of high-quality connectors? Of course, Amphenol also says this:

Originally intended for use as a video connector in radar applications, UHF coaxial connectors are general purpose units developed for use in low frequency systems from 0.6 – 300 MHz. Invented for use in the radio industry in the 1930’s, UHF is an acronym for Ultra High Frequency because at the time 300 MHz was considered high frequency. They can be used when impedance mating is not required.

Well, there you have it: the connector was named UHF back when UHF meant up to 300 MHz. (Today, UHF means 300 to 3000 MHz). I particularly like the comment “They can be used when impedance mating is not required.” What? That does not sound good for RF applications. I do agree that these connectors can generally be used to 300 MHz, but these days the ITU calls that VHF (30 to 300 MHz).

Wikipedia provides a more complete explanation, worth reading.

OK, so the name “UHF” is archaic but it has kind of stuck, the way old terminology sometimes does. I am still going to avoid using this term because it really should be deprecated.

And don’t use these connectors above 300 MHz (UHF frequencies). Unless you have to. Which I did last weekend when the only cable available for my 440 MHz antenna had a PL-259 connector on it.

73 Bob K0NR

The post About That UHF Connector appeared first on The KØNR Radio Site.

June QST: SOTA, POTA and VHF Contest

My article that describes last year’s SOTA/POTA/VHF contest activation from Pikes Peak appears in the June issue of QST magazine. This VHF/UHF activation occurred on the Saturday of the ARRL June VHF Contest and qualified for Summits On The Air (W0C/FR-004 Pikes Peak) and Parks On The Air (K-4404 Pike National Forest). The article highlights the use of the North America Adventure Frequency of 146.58 MHz.

I made 80 radio contacts that day, on the 6m, 2m, 1.25m, 70cm, and 23cm bands. Not a great score for the VHF contest but quite nice for a VHF SOTA and POTA activation. My primary piece of equipment was the ICOM IC-705, which enabled all modes on the main VHF/UHF frequencies.

If you are an ARRL member, look for the article on Page 58 of the print edition of June QST or the online version. Not an ARRL member? Darn, you should fix that if you want to read articles published in QST.

If you are an ARRL member, please look at the article and consider voting for it in the QST Cover Plaque Award. Thanks!

73 Bob K0NR

The post June QST: SOTA, POTA and VHF Contest appeared first on The KØNR Radio Site.

Exploring a New SOTA Summit (W0C/SC-102)

We were looking for a SOTA summit to activate near Salida, so I started to poke around using SOTLAS. There is still plenty of snow at the higher elevations, so we wanted to stay lower. SOTLAS has some useful filtering features that allow you to show only the summits of interest. Initially, I looked for a summit that Joyce/K0JJW and I had not yet activated.

Bob/K0NR and Joyce/K0JJW with SC-102 in the background.

Then I noticed that an unnamed summit (W0C/SC-102) had never been activated, not by anyone. When a summit has never been activated, it is often because it is really difficult to access or it is on private land. Using Gaiagps, my preferred mapping software, I checked out land ownership and the surrounding terrain.

A map of the area around SC-102, which is indicated as the 8380 waypoint.

The summit is on land managed by the Bureau of Land Management (BLM). The box labeled Sand Gulch is Colorado State land. This area is clearly on public land without any private property to deal with. We considered two routes to get to the summit. One option is to hike up from the west, which would probably work. But we noticed a 4WD road that approached from the north side that might provide better access. We weren’t sure how difficult the road would be to drive but we decided to give it a try. The road turned out to be easy 4WD, with just a few steep sections that might prove troublesome if the road were muddy. It presented no problem for our stock Jeep Wrangler. There were several side roads not shown on the map that could be a diversion, so having Gaiagps on my iPhone was helpful.

The red line is the 4WD road and the blue line is the hike to the summit.

The parking spot for the Jeep is shown on the map above. We were careful with the route finding for this summit, even though it is only a mile or so. We wanted to stay on top of the ridgeline and not get lost in one of the side drainages. Gaiagps on my phone recorded the hike as 1.1 miles one way with an elevation gain of 360 feet, so not very difficult.

The Jeep Wrangler parked at the “trailhead”.

The photo below shows the typical terrain as we hiked along the ridge. There was plenty of pinion pine and juniper, along with a surprising number of small cacti. Since the summit is unnamed, we decided to call it Cactus Ridge.

There is no established trail but the bushwacking is relatively easy. This photo shows the typical path with not-so-dense pine trees.

We made contacts mostly on 2m FM (146.52 MHz) using the 50-watt Yaesu FT-90 transceiver driving a 3-element Yagi antenna. I was curious to see how far we could work because the summit is not that high and sits roughly in the canyon of the Arkansas River, between Salida and Canon City. As expected, Salida stations (KD0VHD, K0LPR) were close by and easy to work. Stations in Buena Vista (KF0IHL, KD0MRC, W0BV) also came in quite strong. Our best DX for the day might be N0KM near Center, CO at a distance of 55 miles. But we also worked K0EEP, N0CFM, and KA0SDE camping somewhere near Jefferson, perhaps 60 miles or so, not sure exactly. Although they were due north of us, we had to point the Yagi antenna to the south to work them, apparently getting a nice reflection off one of the high peaks. Similarly, when we worked K0LTH in Guffey (to the north), we had to point the antenna south. We tried to work Amanda/K1DDN in Canon City but were unsuccessful. I thought we might be able to funnel a signal down the canyon to her with a few favorable reflections. No luck with that, but you never know until you try.

Thanks to everyone that listened for us and worked us!

The weather report was sketchy for the day but conditions were cloudy and warm (50 deg F) when we were on the summit at 11:30 AM. Later in the day, after we were back in Salida, we had rain and snow coming down. Springtime in the Rockies.

This was a very enjoyable summit, partially because it had the experience of exploring something new. The easy 4WD road was a pleasant surprise and made us wonder where the other roads in the area lead. At 8280 feet, this summit is only worth two SOTA points. But it’s not about the points, right?

73 Bob K0NR

The post Exploring a New SOTA Summit (W0C/SC-102) appeared first on The KØNR Radio Site.

Three Tips for 2m FM SOTA

Bob/K0NR operating from unnamed summit W0C/SP-094.

I do a lot of SOTA activating using 2m FM and have developed a few operating habits that can really make a difference. These may seem obvious but might be overlooked by operators new to the game. To get an overview of using VHF for SOTA, look at this article: How to Do A VHF SOTA Activation.

Here are three operating tips when using 2m FM for SOTA:

1. Upgrade Your Antenna

A handheld radio is commonly used for SOTA operation because it is a self-contained, compact radio. These radios always come with a rubber duck (electrically-short monopole) antenna. These antennas vary in quality but they are universally poor performers compared to a half-wave radiator. I’ve measured the effectiveness of many rubber duck antennas on 2 meters and they are somewhere between 8 and 12 dB worse than a half-wave radiator. So an easy upgrade is to use a half-wave telescoping antenna. Another popular option with a half-wave radiator is the roll-up J-pole (often called a “Slim Jim” antenna). An even better choice is a small 3-element Yagi such as the 146-3 from Arrow antenna,  which is about 6 dB better than a halfwave antenna. Keep in mind that the Yagi should be held vertically-oriented for FM operating.

2. Open Your Squelch

The squelch circuit in an FM receiver requires the signal to be large enough to flip the squelch open. When operating at weak signal levels, the squelch may mask a signal that is actually readable. A recommended technique is to just open up the squelch control and let the FM noise come through. This maximizes the opportunity to pick out that weak signal out of the noise.

3. Point Your Antenna Everywhere

If you have a directional antenna, make sure you methodically point it in a variety of directions when calling CQ. For example, with a 3-element Yagi, you should divide up the 360 degrees around you into 45-degree sections. Point north, make a call, point northeast, make a call, point east, make a call, and so forth. Also be aware that the direct path to another station may not be the strongest path. This is especially true if you have tall summits around you that can block or reflect your signal. Many times I’ve pointed in the “right direction” to work another station but then found that the signals were strongest with the antenna pointed away from the direct path. So the secret is go ahead and try different antenna orientations to maximize the signal strength, even when you know the physical direction to the other station. Sometimes the radio waves decide to take another path.

Those are my three tips for today.
Do you have any to add?

73 Bob K0NR

The post Three Tips for 2m FM SOTA appeared first on The KØNR Radio Site.

How About An Icom IC-905?

Being an enthusiast for bands above 50 MHz, I suppose I should weigh in on the new IC-905 from Icom. The street price for the basic unit is ~$3500, with various options and accessories at additional cost.

Let’s be clear about one thing, this radio is one impressive piece of technology. There is no other radio on the market that comes close to covering these VHF/UHF/SHF bands: 144, 430, 1200, 2400, and 5600 MHz (and optional 10 GHz). I won’t mention all of the features and specs covered here. I really appreciate that Icom is investing in equipment for VHF and higher, as evidenced by the IC-9700 and this radio.

For me, there are two main uses I would consider for the IC-905: Summits On The Air (SOTA)  and base station use:

SOTA

I focus on VHF/UHF for SOTA with 144 MHz always carrying the load in terms of making radio contacts. Lately, I have put more effort into 432 MHz and 1.2 GHz. I’ve also been trying to get out of the FM rut and work more SSB and CW on those bands. I really should get going on a portable digital station for FT8 and other modes. I have a good collection of gear to choose from, ranging from basic 5-watt FM handhelds to an IC-705 and an IC-9700. OK, the IC-9700 is a bit large to drag up most summits but I have taken it on some easy hikes and drive-up summits. Joyce/K0JJW and I also have a pair of Alinco triband handheld radios (DJ-G7T) that have 1.2 GHz FM. These radios are popular with SOTA enthusiasts due to their affordability and compact size.

What does the IC-905 offer for SOTA? Well, obviously it is a reasonable way to get on 5 or 6 bands with all modes. However, I already have the IC-705 that covers 144 and 432 MHz (and 50 MHz). Having CW/SSB on 1.2 GHz is very attractive to me but 2.4 GHz and 5.6 GHz are rarely used for SOTA. Sure, maybe the introduction of the IC-905 will change that. Maybe, but probably not. Someone commented in an online forum that you better buy two IC-905s and loan one out so you have someone to work. For my interests, I would much rather have a VHF/UHF-only variant of the IC-705 that covers the 50, 144, 440, and 1200 MHz bands. But I have come to accept the fact that radio manufacturers don’t develop radios just for me.

Base Station

The other option is to use the IC-905 to get on the higher bands from my home station. I am in the process of building a VHF+ station at our cabin in the mountains, which is in a good VHF/UHF location. Honestly, my focus is on getting a tower up with good size Yagi antennas for 50 MHz and 144 MHz. Although I have operated a lot on these bands, it has usually been from portable and rover stations, during one of the VHF contests, or as a SOTA activation. I am looking forward to having an effective permanent station on the two most popular VHF bands.  I am debating how much effort to put into the 430 MHz and 1200 MHz bands at the new station, and 2400 and 5600 MHz are not currently in my plans. Besides, the IC-9700 has me covered for 144, 430, and 1200 MHz. So right now, I don’t see the IC-905 being part of the home station, but that could certainly change with time.

Price

What about the price? $3500 is a serious piece of change but probably not unreasonable for what this radio can do. Some people have said it is worth it and some think it is way too expensive. Price is always an issue, but for me it probably doesn’t matter that much. For the most part, I am saying the radio doesn’t fit a need I have. OK, if the price were a lot lower (like $1500), it would affect my point of view. But at that price, Icom would be leaving money on the table with the folks that really want to get on 2.4, 5.6 and 10 GHz.

So my conclusion is that I probably won’t be buying an IC-905 at this time, but things can always change.

What are your thoughts?

73 Bob K0NR

The post How About An Icom IC-905? appeared first on The KØNR Radio Site.

Close to Denver: Green Mountain (W0C/FR-107)

Sometimes you just want a close-in SOTA summit that is easy to access and allows you to get on the air. On the west side of greater Denver, a few summits meet that requirement. One of them is Green Mountain (W0C/FR-107), near the intersection of I-70 and C-470. This would make a good beginner summit or an easy-access summit for visitors to the area. Joyce/K0JJW and I activated this 1-point summit today.

The blue line marks our route up Green Mountain, starting at the trailhead on South Rooney Road.

Access is easy and convenient, the trailhead can be found by going west on Alameda Parkway, off C-470, then north on S Rooney Road. There is a large parking lot there and an obvious trailhead with pit toilets. From here we hiked east over C-470 into William Frederick Hayden Park. We followed signs for the Green Mountain Trail, which is basically an unimproved road, to the summit of Green Mountain (see map above). This is not the only option because the park has an extensive trail system to explore. Check out the Lakewood parks map here. Also, you can check the trail conditions here. My mapping app recorded the hike as 1.6 miles (one way) with an elevation gain of 800 feet, not very difficult but still a decent hike. On a cool Saturday afternoon, we met many hikers and mountain bikers on the trail.

The view looking west from Green Mountain.

This hike starts out with a lot of road noise from C-470 but things soon quiet down as we left the highway behind. On the summit, we could see many higher summits to the west and downtown Denver to the east. We only had a couple of handheld VHF/UHF radios with us and made a bunch of contacts on 2m FM. This is usually the case when you have line-of-sight to the Denver area, with plenty of activity on 146.52 MHz.

This summit is not the best SOTA summit in the state but if you are itching to do a SOTA activation without driving deep into the mountains, this one will work!

73 Bob K0NR

The post Close to Denver: Green Mountain (W0C/FR-107) appeared first on The KØNR Radio Site.

Blogging With AI (ChatGPT)

Sorry that I have not been posting much on my blog. I have several other projects consuming my time and this blog has been neglected.

Then, it hit me: I should just let ChatGPT, a free artificial intelligence (AI) platform that is getting a lot of attention, write my blog for me. All the Cool Kids are Using It. I just entered “Please write my next blog post about VHF ham radio” and this is what I got back:

VHF Ham Radio: Exploring the World Above 50 MHz

When most people think of ham radio, they usually picture a person sitting in a dark room, talking into a large radio with a huge antenna. However, ham radio can be much more than that, especially when you start exploring the VHF bands.

VHF, or Very High Frequency, refers to the portion of the radio spectrum between 30 and 300 MHz. This includes the 6-meter (50 MHz), 2-meter (144 MHz), and 70-centimeter (440 MHz) bands, which are commonly used by amateur radio operators for local and regional communication.

One of the main advantages of VHF ham radio is that it allows for much greater range than the traditional HF bands (below 30 MHz). This is because VHF signals travel mostly in a straight line, and are less affected by the ionosphere and other atmospheric conditions that can impact HF propagation.

In addition to traditional voice communication, VHF ham radio operators also use a variety of digital modes such as Packet Radio, APRS, and D-STAR, which allow for the exchange of data and information over the airwaves.

Another popular VHF activity is contesting, which involves making as many contacts as possible in a short period of time. Contesting can be a fun and exciting way to improve your operating skills and test your equipment.

VHF ham radio is also a great way to get involved in emergency communication and public service. Many amateur radio clubs and organizations work closely with local authorities to provide communication support during emergencies and events.

If you’re interested in exploring the world of VHF ham radio, there are a few things you’ll need. First, you’ll need a radio that covers the VHF bands. There are many options available, from handheld transceivers to base stations with large antennas.

You’ll also need an antenna that is specifically designed for VHF operation. These antennas are typically shorter and more compact than HF antennas, and are available in a variety of types and configurations.

Finally, you’ll need to obtain a ham radio license from the FCC. The process is relatively straightforward and involves passing a written exam that covers basic radio theory, regulations, and operating procedures.

In conclusion, VHF ham radio offers a world of opportunities for communication, experimentation, and public service. Whether you’re a seasoned operator or a newcomer to the hobby, there’s always something new to discover on the VHF bands.
[ end of ChatGPT article]

How many factual errors did you spot?

73 Bob K0NR

The post Blogging With AI (ChatGPT) appeared first on The KØNR Radio Site.


Subscribe FREE to AmateurRadio.com's
Amateur Radio Newsletter

 
We never share your e-mail address.


Do you like to write?
Interesting project to share?
Helpful tips and ideas for other hams?

Submit an article and we will review it for publication on AmateurRadio.com!

Have a ham radio product or service?
Consider advertising on our site.

Are you a reporter covering ham radio?
Find ham radio experts for your story.

How to Set Up a Ham Radio Blog
Get started in less than 15 minutes!


  • Matt W1MST, Managing Editor




Sign up for our free
Amateur Radio Newsletter

Enter your e-mail address: