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!
Gear:
Note: All Amazon, CW Morse, ABR, Chelegance, eBay, and Radioddity links are affiliate links that support QRPer.com at no cost to you.
- Icom IC-705
- Pelican 1400 Waterproof Case
- Icom IC-705 3D Printed Foot
- ABR Industries Cable Assembly Builder (Use Coupon Code ABR10QRPER for 10% Discount!)–Note that I used RG-174 with a PL-259 and BNC in this video. Typically, though, I prefer RG-316.
- Chelegance MC-750
- CW Morse “Pocket Paddle”
- GraphGear 0.9mm 1000 Automatic Drafting Pencil
- Rite In The Rain Top Spiral Notebook
- Camera: DJI OSMO 4 action camera with Sensyne Phone Tripod
On The Air
Despite it still being fairly early in the morning, I decided to hit 20 meters and see if there was any activity on the bands.
After spotting myself, I called CQ POTA and the hunters (thankfully) started calling me back.
Within nine minutes, I worked the ten contacts necessary to validate the activation.
I continued operating and racked up a total of 35 contacts in 35 minutes. One contact per minute is the perfect cadence for POTA!
I should add here, again, that if you were calling me that morning with a weak signal, I just couldn’t hear you due to the QRM levels.
Here are my logs:
QSO Map
Here’s what this five-watt activation looked like when plotted out on a QSO Map:
Activation Video
Here’s my real-time, real-life video of the entire activation. As with all of my videos, I don’t edit out any parts of the on-air activation time. In addition, I have monetization turned off on YouTube, although that doesn’t stop them from inserting ads before and after my videos.
Note that Patreon supporters can watch and even download this video 100% ad-free through Vimeo on my Patreon page:
Click here to view on YouTube.
Post-Activation Hike
By the time I completed the activation, the rain was passing.
Mike and I finished packing up the final few things in the car and we made our way to the Rainbow Falls Trailhead.
The three-mile round-trip hike was quite easy and the rainbow falls were amazing.
I look forward to visiting Gorges State Park again, but I’ll likely bring my magnetic loop antenna next time. While I doubt the loop will mitigate all of the noise, I suspect it will have a significant impact on it.
Since I plan to take my wife and daughters to Gorges State Park this summer, I’ll have another opportunity to give it a go!
Thank you
Thank you for joining me during this activation!
I hope you enjoyed the field report and my activation video as much as I enjoyed creating them!
Of course, I’d also like to send a special thanks to those of you who have been supporting the site and channel through Patreon, and the Coffee Fund. While not a requirement, as my content will always be free, I really appreciate the support.
As I mentioned before, the Patreon platform connected to Vimeo makes it possible for me to share videos that are not only 100% ad-free but also downloadable for offline viewing. The Vimeo account also serves as a third backup for my video files.
Thanks for spending part of your day with me! Have an amazing weekend!
Cheers & 72,
Thomas (K4SWL)
It’s fun to casually compare logs and see what hunters we have in common.
Shout out to Les, KI5GTR, in Arkansas. And, of course, Brian, K3ES.
I noticed in the video the car was plugged in – I wonder if you were getting QRM from that as well.
No, the car charger created no discernible QRM. If it was causing noise, it was way lower than the arcing noise. 🙂 I couldn’t tell a difference when it was plugged in or not. That’s a brilliant observation, though, on your part!
Great reports. I love your photos.
I think you meant QRN (noise) instead of QRM (interference).
Keep up the great work. Thanks for your reports.
So I think there’re actually multiple definitions of QRM and QRN out there. I wouldn’t be surprised if the meaning has changed over time as well.
QRM, to me, has always meant interference of the man-made variety. An adjacent signal or station, or electronics that spew RFI (radio frequency interference). In this case, power line arcing would also be considered QRM. For example, in the UK, there was a movement to stop noisy internet-connected devices being installed in many neighborhoods. The group championing this were called UK-QRM.
QRN, to me, has always represented atmospheric noise: static crashes that are often associated with distant thunderstorms and band noise generated by changes in the atmosphere caused by the solar conditions. Noise sources of the natural variety–not from a man-made source.
https://en.wikipedia.org/wiki/Q_code
Cheers,
Thomas
When you are in a rented cabin, how do you pass the coax to the outside? Do you just keep a window slightly open?
So in this case, I just rant the coax out the door. I know that the windows are operable in that little cabin, but I never checked to see if the screen can be removed. If not, then you would need to crack the door to run the cable outside. I just never needed to do that, so I’m not sure about that particular cabin.
I enjoy your adventures and reports. Question. What is the DSP you refer to? I see NB and NR but not DSP. THANKS.
MARTIN K0BXB
Great question! So I’m referring to the DSP (Digital Signal Processing) that’s essentially running the Noise Reduction and Noise Blanker functions.
It’s a shame that even fancy QRP radios like the IC-705 don’t have input for separate RX antennas. It would be really great to be able to use your vertical or a EFHW (for example) for its superior TX performance and the Mag Loop for its QRN busting RX possibilities. There’s an idea, someone make a small external RF switch box that runs off of a 9 volt battery that either senses RF or uses the transceivers amplifier switching to switch between RX and TX, at QRP power levels, this shouldn’t be to difficult.
I live 5 minutes away from the park. Just right
Around the corner.
Let me know when you return.
Dave
KJ4CIZ
I’ll plan do that!
The Chelegance MC-750 antenna is a real keeper and no problem passing through customs or security. They even scan bags on trains…no issues
I used it to activate ES-1473 in Sevilla
Bands were funny but managed to eke out VE2EH on 20m
I also worked EA1BUL who I worked from various Ontario parks
Busted a pile up to work AO75CL. Oh he is in Spain.
73s
John VE3IPS
Next up a cabin trip……..