Tag Archives: QRM

Beyond the Beacon: Conrad Discovers the Unexpected Benefits of WSPR

Many thanks to Conrad (N2YCH) who shares the following field report:


QRPppppp….WSPR

By: Conrad Trautmann (N2YCH)

WSPR, or Weak Signal Propagation Reporter, is a digital mode you can select within WSJT-X. You can use the data that’s generated by the WSPR network to check your own antenna’s performance for transmitting and receiving and also to see what paths are open by band at a particular time of day from your QTH. Recently, I’ve been using WSPR to improve my own antenna systems and to help reduce local noise sources.

Originally developed by Joe Taylor, K1JT, an approximately two minute QRP transmission contains the originating station’s call sign, the maidenhead grid locator and the transmit power level being used. Stations typically use 250mw up to 5watts when they send these signals. WSJT-X allows you to select how often you want to send this transmission and what bands to transmit on. There’s an embedded schedule in WSJT-X that allows “band-hopping” for stations using a multiband antenna to transmit on different bands. When not transmitting, it listens for and decodes other stations transmitting and can post “spots” of those stations to the WSPR network database.

WSJT-X WSPR mode
WSPR Band Hopping Schedule (click to enlarge)

Here on QRPer.com, Thomas, K4SWL posted in this field report what the various flavors of QRP power levels are…

  • QRP: 5 watts to 1 watt (for some contest 10 watts = SSB QRP)
  • QRPp: Less than 1 watt to 100 mw
  • QRPpp: Less than 100mw

Did you know that there are more than 3,000 WSPR HF beacons running on all of the amateur bands all over the world at QRP power or less? Many are running 250mw or less. If you open up WSJT-X and select the WSPR mode, you’ll see that the pull down for power levels give you these options:

  • 37dbm = 5w
  • 33dbm = 2w
  • 30dbm = 1w
  • 27dbm = 500mw
  • 23dbm = 200mw
  • 20dbm = 100mw
  • 17dbm = 50mw
  • 13dbm = 20mw
  • 10dbm = 10mw
  • 7dbm = 5mw
  • 3dbm = 2mw
  • 0dbm = 1mw

You could transmit your own beacon if you choose to using WSJT-X. You can also receive many of the 3,000+ beacons that are on the air right now if you wanted.

Why, you ask?

Let me tell you about the WSPR journey I’ve taken over the past few months and how what I’ve learned has benefitted me, my station and my antennas. Here’s how extreme QRPpp signals can help all of us.

I’m an avid digital operator, and I’ve tested many of the digital modes that WSJT-X, FLDigi, VarAC and others have to offer.

WSPR (Weak Signal Propagation Reporter) is a program embedded as a mode in WSJT-X and you can set it to transmit at the various power levels I listed above and band hop to different bands if your antenna can support those frequencies. When it’s not transmitting, it will receive and post the beacons it hears to the WSPRnet.org web site. For anyone familiar with pskreporter.info, WSPRnet.org is similar in that it provides maps of where and when “spots” are received and the relative signal strength the signals were when received by station, the mode and frequency.

After setting my station to transmit and receive on WSPR and looking at my spots on WSPRnet.org that were reported by receiving stations over the previous day, it was a thrill to see my 250mw signal making it out all over the world. Amazing actually, that such a small amount of power could travel that far. 250mw to Antarctica? That’s pretty good.

I bought a QRP-Labs QCX transceiver and the external companion GPS clock, which supports running WSPR transmission stand alone, without tying up a computer. Then I learned about the Sotabeams WSPRLite Antenna Tester (a 250mw WSPR transmitter) and the various WSPR transmitters offered by ZachTek which can also run without needing a computer.

My goal was to have WSPR beacons transmitting on as many bands as possible. Combining them into a single, multiband antenna posed its own problems, which is a topic for another article. However, all of these solutions just transmitted. I was hoping to also be able to receive and post spots as well.

Then, QRP-Labs (shout out to Hans Summers) came out with the QDX and then the QMX, both of which connect to a PC and are controlled by WSJT-X to do the band hopping transmitting and receiving. Like FT8, WSPR does depend on timing to work best, so using an external GPS clock for the QCX or connecting a QDX or QMX to a computer that can get it’s time from the internet can help keep the transmission cycles in sync with the receiver sites for best reception results.

Various WSPR transmitters and transceivers

This is cool stuff, but still, what’s the point? That’s when a friend I made in the WSPR community, Tom, WA2TP pointed out how to use all of these beacons to improve my station’s receiving capabilities. I have a good HF receiver and a dipole antenna and a hexbeam on a rotor and I figured I was good to go. I was making contacts without any problems. Tom told me this: “It’s all about the noise.”

He recommended using a wideband SDR called a Kiwi that can view the entire HF spectrum from 0 -30MHz on a waterfall at one time. My ICOM IC-7610 can connect to a PC and work with HDSDR software which has a waterfall, but it will only show you the spectrum of the particular band you’re on, not the entire HF spectrum at once. The Kiwi shows the entire spectrum from 0 to 30 MHz and when set up just right, you can see noise in there…a lot of noise, emanating from all sorts of things.

If you’re trying to receive a 250mw WSPR beacon signal transmitting from Australia, the noise from the after-market, wall-wart switching power supply connected to your cell phone charger a few feet away from your antenna could be way noisier and will blank that VK beacon right out. Your antenna and ability to hear distant signals is only as good as how low or quiet the local QRM is that we all have to deal with.

So began my hunt for noise, with a lot of guidance from folks with experience at it. Continue reading Beyond the Beacon: Conrad Discovers the Unexpected Benefits of WSPR

Cabin POTA with the IC-705 and MC-750 at Gorges State Park!

As I mentioned in this previous field report, my buddy Mike and I spent the third weekend of March at Gorges State Park (US-2732) in Sapphire, North Carolina. We had a great weekend of hiking and just hanging out. Of course, I fit in a few activations!

On the morning of Sunday, March 17, 2024, after a nice breakfast and beautiful sunrise, we started packing up. Since we rented a cabin this year, it was an easy process–especially since it was also raining lightly. While I love tent camping, I’m not the biggest fan of packing up a wet tent and gear because later in the day I have to attempt to dry it all out back home.

The cabin also made it very comfortable to do a little Parks on the Air (POTA) until the rain passed and we could start our hike.

I set up my MC-750 vertical next to the cabin.

Inside, assuming I might have more radio frequency interference (QRM) to deal with, I chose my Icom IC-705.

The cabin had a small side table attached to the wall which was the perfect spot to set up my station close to the front door and porch. The weather was very temperate that morning, so I simply left the front door of the cabin open while I operated.

I was correct about the QRM: its pervasive throughout most of the park and is due to arcing on the high-tension power lines that run through the site.

Other than the QRM, Gorges is an amazing park to do POTA.

While I played Parks on the Air, Mike caught up on a book he was reading. Neither of us were pressed for time, so it was a pretty laid-back morning.

QRM Mitigation

After hooking up the IC-705 to the MC-750 and turning it on, the QRM was not only audible–that unmistakable frying sound–but it was clearly visible on the IC-705’s color display.

The noise level was about S5-S6 and persistent.

The IC-705 is a 21st-century radio and I decided to use some of its 21st-century, SDR-powered features in order to improve the audio.

First, I turned on the Noise Blanker (NB). While this feature works best for pulse noises (engine noise and electric fences, in my experience) it also removes a layer of noise from persistent arcing as well.

Next, I also used the IC-705’s built-in DSP (Digital Signal Processing). By turning on the DSP, another layer of noise is removed.

With both NB and DSP engaged, the audio was much more pleasant and less fatiguing.

Keep in mind that even though the noise was minimized in the audio, it was still there in the receiver so this didn’t help much with recovering weak signals under the elevated noise floor. It just made playing radio much more pleasant! Continue reading Cabin POTA with the IC-705 and MC-750 at Gorges State Park!

Pairing the TR-45L Skinny and the MC-750 at Gorges State Park!

Once a year, I meet up with my friends Monty and Mike for a weekend of camping. We’ve been friends for over 30 years, so it’s always brilliant hanging out with them, hiking, and just enjoying the break in our busy family lives.

This year, we planned our weekend campout for March 15-17, which is slightly earlier in the year than we usually do, but all of us have complicated schedules in April, May, June, and July. So March it was!

We chose to camp at Gorges State Park (US-2732) in Sapphire, North Carolina.

We also decided to opt for one of the park’s five cabins instead of tent camping. The park ranger I spoke with on the phone prior to making the reservation convinced me that we should reserve one of their newly built cabins. The cabins can sleep six, have electricity, and even have heating and air conditioning.

Mid-March in the mountains of western North Carolina is a fickle part of the year. It can be cold, hot, dry, or wet–all easily within one weekend. Choosing a cabin would mean packing in a lot less gear. Done!

Unfortunately, only a few days prior to the camping trip, Monty had to duck out to attend a funeral. We really missed hanging out with him.

Gorges State Park

To my knowledge, I had never been to Gorges State Park. It’s one of the newer parks in the NC system and, frankly, it’s located in a part of WNC that I rarely travel through these days.

The park is vast, and there are a number of trails that lead to waterfalls.

The visitor’s center was built in 2012 and is really impressive. We stopped by there and spoke with staff about some of the hiking options.

I’ve always preferred state and national park camping facilities over private campgrounds. They’re typically well-maintained, and the sites are spaced apart (so I can easily set up an antenna!).

Cabin #5

The camping area at Gorges is one of the nicest I’ve ever seen. It’s all very new. The cabins and shower/bathroom building are only two years old.

The weekend, overall, was warm during the day and cool at night with periods of rain. We both felt pretty happy we’d picked a cabin for the weekend–packing up wet camping gear is never all that fun!

Saturday morning, Mike and I planned to do a bit of hiking, and I wanted to fit in a short activation.

Picnic Shelter Activation

At one of the trailheads for a short hike, we found a spacious picnic shelter. Despite the amazing weather that morning, there was no one else at the shelter.

I scoped out the trees around the perimeter of the shelter, and most were pretty small trees with larger trees behind them. I decided that it would be easier to simply deploy my Chelgence MC-750 vertical.

I brought three radios along on this camping trip: my TR-45L Skinny, Icom IC-705, and Elecraft KH1. I chose the Skinny for this activation! Continue reading Pairing the TR-45L Skinny and the MC-750 at Gorges State Park!

Out Of My Element: An Urban POTA activation at the Thomas Wolfe Memorial

It’s funny, but until September 7, 2023, I had never activated one of the closest POTA sites to my home: the Thomas Wolfe Memorial (K-6853).

I remember back in 2020 when I really kicked my POTA activations into high gear, I made a spreadsheet of all of the POTA sites within a 2 hour drive of the QTH and started activating them one by one.

At the time, almost 50-60%, or possibly more, had never been activated. Keep in mind that in early 2020, POTA had a wee fraction of the activity it has today.

It was a lot of fun especially considering those were the early days of the pandemic and it was just nice to get out and about. Any excuse, right?

The Thomas Wolfe Memorial is on North Market Street in Asheville, NC.

One of the parks on my list was the Thomas Wolfe Memorial but being a small historic site in an urban setting, they were closed for quite some time during the pandemic. There was nothing to stop me from walking on the site–or pulling up in their parking lot–and doing an activation while they were closed, but I just didn’t feel like it should be fair game when closed.

Then restrictions loosened up and, frankly, I just sort of forgot about it.

I tend to activate parks in rural areas and I am prone to overlook urban sites (although quite a few of my activations in Canada last year were urban).

Thomas Wolfe Memorial (K-6853)

On Thursday, September 7, 2023, I dropped off my daughters at school then made my way to a doctor’s appointment. I arrived at the office, gave them my name at the front desk, and then they reminded me that we had re-scheduled this particular appointment for later in the month.

Doh! I forgot to make the change in my calendar.

All of the sudden, I had a bit more free time!

Of course, I always fill free time with POTA activations, and I already had radio gear in the car, so it was only a matter of deciding where to go.

I called the Vance Historic Birthplace (about a 25 minute drive) to see if they were busy. Their director (who I know quite well at this point) told me that a large group was on the site, but would be gone by 1:30. That timing didn’t work for me, so I consulted the POTA map.

Since the POTA site used my coordinates to find the closest park, I was reminded that K-6853 was a mere 3 minute drive from the doctor’s office. I could have walked there.

I gave the site a call to ask for permission (again, I always do this for small historic sites) and they told me I’d be most welcome.

The site is on a small urban lot and consists of two buildings: the visitors’ center, and the Old Kentucky Home boarding house. Continue reading Out Of My Element: An Urban POTA activation at the Thomas Wolfe Memorial

Rich re-activates Santa Fe Prairie State Park with QRM-busting in mind

Many thanks to Rich (KQ9L) for sharing the following field report:



Field Report: Testing a horizontally-polarized antenna at a high QRM POTA site

by Rich (KQ9L)

I wanted to give a quick follow up report from Santa Fe Prairie State Park (K-7839).

As you may recall I wrote up my POTA activation from this park on Oct 23, 2022. I made 15 Q’s that day but deep down felt I could do better. The setting of the park is quite industrial and consequently the man made noise is bad. Reflecting back on this activation, I feel that the limited the number of QSO’s I made that day was due to this QRM.

I resolved to try again but this time my objective was to figure out a solution to mitigate the effects of the QRM on my QSO count. Thinking about the problem, I recalled than manmade noise typically is vertically polarized and therefore for my second attempt, I decided to test this and use a horizontal antenna.

As luck may have it, here in Chicago we continue to experiencing unseasonably warm weather and my work schedule wasn’t too busy on Thursday, November 3, 2022, so it seemed like a great chance to put my theory to the test.

For the antenna, I decided to use one which I have owned for awhile, but have never used. I had purchased a RadioWaves Double bazooka from an online retailer some time back when they were on sale and planned to set up it a flattop dipole.

If you recall from my description of the Santa Fe Prairie State Park, there is a scenic overlook which has a tree mounted pulley system perfectly spaced to mount a 20m dipole. Although this would be the first time I used the system, it turned out to be a well designed and intuitive hoisting solution to use.

The “pulley” is actually an eyelet with paracord running through the eyelet. The paracord is in a continuous loop just like rope on a flag pole. By employing a simple overhand knot I secured the end of the antenna to the paracord and hoisted the antenna up into the tree about 20ft. It literally took a few minutes and I was ready to go.

Antenna was fed with my RG-316 feedline with built in common mode choke. Since a dipole is a balanced antenna system, it really doesn’t need the choke, but it was the coax that I had packed with me and I figured it wouldn’t cause any harm or negatively affect my test. I was QRV by 3:20pm, and anxious to get on the air. Continue reading Rich re-activates Santa Fe Prairie State Park with QRM-busting in mind

Why a strong activator might not hear your call

I had a conversation recently with a ham who upgraded his license for HF privileges primarily to do park activations in the POTA and WWFF programs.

He mentioned that he had a few successful park activations under his belt but was left scratching his head on a couple of occasions when he attempted a Park-To-Park (P2P) contact but could not be heard by the other activator.

He did all of the right things: announced his call sign followed by “Park To Park” twice and was patient while the activator worked a small pile-up.

In one case, he said the other operator had an incredibly strong signal–and having always heard, “if you can hear them, you can work them“–he was really baffled that he couldn’t make contact especially being a desirable P2P. His activations were successful so he knew it wasn’t an equipment issue.

He asked for my input, so I thought I might share a few points here as this is not at all uncommon–please comment if you think of others:

Big power, small antenna

Some activators operate mobile and don’t actually deploy their gear in the field. They simply drive up to a site, turn on their mobile HF rig in the car, and start making contacts with the mobile whip antenna mounted on their vehicle. There’s nothing wrong with this approach in the POTA program (just keep in mind mobile activations are not allowed in SOTA). Mobile activators can rack up numerous park activations in one day often regardless of weather or any site restrictions.

Mobile vertical antennas like Screwdrivers, Hamsticks and whips are quite impressive and, many activators swear by them. Not only do they work well in mobile situations, but they can also be quickly set up on a tripod in the field and many models can take a full 100+ watts of power.

If an activator is pumping 50-100 watts into a small, resonant mobile antenna, their signal is getting out there. But since their antenna might not actually have a lot of gain or efficiency on 40 or 60 meters, it can’t compete–in terms of reception–with a large aperture wire antenna.

In this scenario, the activator might be logging a load of stations, but they may not be able to hear your signal if it’s weaker than the others in the pile-up.

QRM on the other end

Often summits are the location of clusters of commercial transmission antennas and towers that can cause interference

This is a big one, actually, and affects both park and, especially, summit activations.

Sometimes the other activator’s site is plagued with QRM (radio interference) emanating from power lines, nearby buildings, transmission equipment, and other electronic sources.

That QRM will not typically affect their transmitted signal, but it will have a dramatic impact on what they can receive and hear.

For example, I recently attempted to activate a game land I’d never been to before.  On Google Maps satellite view, the site looked pretty darn remote and there were no buildings in sight. When I arrived on site, I set up my station, spotted myself, and started calling CQ POTA.

When I turned up the volume on the radio, it hit me that my noise level was a solid S8-S9! Turns out, there was a nearby power line that was spewing broadband noise across the entire HF spectrum. It was pretty much inescapable–there were no unaffected HF bands.

Had I really wanted to continue with that activation (I did not) I would have only been able to work stations with signals that were above my high noise floor. Perhaps one in five contacts at best. My chasers would have all been been left scratching their heads.

QRM isn’t always S8, but even an S5 or S6 noise level might wipe out 40-50% of the signals the activator can hear.

While hitting the field is usually the best way to escape QRM, there are spots that are as noisy an an urban neighborhood.

QSB

This is a big one; especially with the unsettled conditions we’ve had over the past couple of years.  QSB, or signal fading, can be a proper obstacle in completing a contact.

If you’ve been watching my activation videos, you’ve no doubt seen chasers that call me with a 599 signal and when I respond to them, I hear nothing but silence. In those situations, I’ll repeat my reply with their callsign and signal report a few times in a row. I do this because QSB is a bit like having a three year old playing with your volume control while you’re on the air.

Seriously, imagine that three year old turning up the volume, then turning it back down, then turning it up again, and so on. It essentially has the same effect. Sometimes QSB is shallow and slow, other times it’s deep and fast–or it can be any variation in between (including deep and slow which is the worst).

In those situations as an activator, I reply a few times in a row with hopes to catch the QSB on the upswing  so I can have a window of contact with the other station. When I do make contact, I try to keep the contact as short as possible so there’s hope for a complete exchange.

As a hunter, you have less control because your only hope is that QSB will be at the peak of signal strength when you call the activator.

Environmental distractions

If you’ve been doing park and summit activations for very long, you’ve no doubt experienced some “environmental distractions” during an activation.

I’ve been at parks before when the grounds crew were blowing leaves, mowing, and using other lawn equipment. It can be proper audio QRM especially if you don’t have an option to wear headphones to isolate those noises.

Sometimes the wind can cause a lot of extra noise. I’ve also been in shelters where the rain hitting the tin roof (while somewhat soothing) adds a lot of extra noise.

I’ve also been on summits and in parks where other hikers and passersby start asking questions while I’m in the middle of handling CW contacts.

My buddy Vlado (N3CZ) draws a crowd during a joint park activation on the Blue Ridge Parkway

They don’t understand that you’re actually in the middle of an exchange and need your attention focused. 🙂 For so many of them, it’s the first time they’ve ever seen/heard someone operating Morse Code and they’ve loads of questions. I hate to pass up an opportunity to promote amateur radio, so I’ll often pause the activation to talk with them.

In summary

If you know your radio equipment is functioning as it should but you can’t seem to grab the attention of an activator, keep in mind that it’s likely them, not you.

They’re not ignoring you, they simply can’t hear you.

The best practice for eventually making contact is to be patient and persistent. If you’re an activator trying to work another activator for a P2P or S2S (Summit To Summit) contact, keep sending P2P or S2S with your call. Often, other hunters will hear you and point out to the activator during their own exchange that there’s a weak P2P or S2S operator calling. More often than not, that’s your ticket to busting through!

Did I miss something? Please comment and share your thoughts and tips!