POTA Antenna Test 3

I compared the 20m EFHW with the 12.5m EFRW at Sam Lewis (US-1418). I threw really high and made both antennas nearly vertical into high trees, not inverted-v.

EFHW could hear pretty well, and the SWR sweep showed again that I could shorten it, so I did lower it and take off a few cm.

The EFHW didn’t seem to like its counterpoise. With the counterpoise, it was giving me an SWR of 2-2.5:1 on 40m when I transmitted. If I removed the counterpoise or kept it coiled up, the SWR was lower. I still made most my contacts on 40m.

I think the radio may have again been interfering with the mouse when transmitting. I already had chokes on both ends of the feed line, but adding the counterpoise helped that common mode interference. It was a rough day.

The EFRW would not tune well at all on 40m with or without its single counterpoise. That surprised me greatly, because I had tested that same unun with my existing EFRW antenna out the front window at home.

I wonder if it had something to do with each antenna being mostly vertical. I wonder if they needed more radials instead of a single counterpoise. K4OGO (Walt of Coastal Waves and Wires) always adds so many radials to his verticals.

This had me questioning everything. I thought I was doing something really good by getting the wires high and vertical. When I brought the radio home and connected to the same old EFRW, it was again performing normally.

I also learned that the POTA website cuts off your activation and starts a new one at 00:00UTC, 8pm, so I ended up with 2 QSOs counting toward a second (incomplete) activation at the park.

pota  efrw  antenna  efhw 

EFHW Test 2

I ran out to Susquehanna Riverlands State Park (US-9719) to test the EFHW again. This time I tied it to a bush and a picnic table and raised the center with the fishing pole mast.

I took the time to sweep all the bands with the X6100’s built-in analyzer app. 40m looked like it could stand to have the wire slightly shorter, but when I transmitted, the SWR looked fine. I saw about 1.5:1 SWR on 40, 20, and 15. 10 was a little off, so I guess I’ll add the 100pf capacitor that most people use.

The tuner made 12m and 17m work, so I made FT8 contacts on 40m, 20m, 15m, and 17m.

I was also trying out some of the combo winder/unun I 3d printed and made some notes. I’ll post my remix soon of another person’s OpenSCAD code. I like the all-in-one designs that wrap up into one package, but I wonder how much that will hinder my random experimentation with antennas.

While transmitting, I noticed the Evolve 3 laptop’s mouse would stop responding. I had seen this on other laptops using the 1/4 wave HF vertical. I added the common mode choke to the feed line near the radio, and that cleared up. There was already a choke near the antenna, but I guess it wasn’t enough. I love when I can see a clear cause and effect or problem and solution.


Ben and I took the radio gear for a walk to Hawk Point overlooking the river in Susquehannock State Park (US-1425) for a POTA activation. We threw the 20m EFHW into the trees in an inverted-V. I checked the SWR on 15M, and it came in about 1.5:1 or so.

I could hear really well with it, and I contacted Argentina, Texas, California, and Italy among other closer places on 15M FT8. I spun the dial down to 20M SSB to hear a park in Illinois, but it was busy and the sun was setting quick, so I didn’t wait to try to make contact.

I’ll have to try the other bands next, but my randomly starting up on 15M worked great.

Using the little box as a winder for the wire didn’t work out so well. It became an immediate tangle as I tried to unwind it. I’ll switch to a 3d-printed winder instead.

efhw  pota 

Noise from Flares

I had heard a bit of pulsing noise on all the FT8 bands the other night.

On the Morning Grind Net, Rick, WB3CSY, mentioned this as well and that he suspects it came from a solar flare that was hitting us.

solar  noise  hf 

985 Workbench Net - 2024-05-13

My Week in Radio

  • I purchased some power cables that split out the 12V line out of USB-C, so I can power my radio from a USB-C power brick/jump-starter battery.
  • Marie and I relaunched my EFRW even higher into the the tree in the front yard. I used the slingshot out the second-story window, while Marie watched that the street and sidewalk were clear.
  • I did the RTTY test and FT4 sprint last Thursday.
  • I saw some better propagation on FT8 before the weekend’s solar storm: Ukraine, Northern Ireland, and Greenland at the arctic circle.
  • While the bands were dead over the weekend, I built a couple new, lighter antennas for POTA. I cut and tuned some 20m-long EFHW wires and tuned them with NanoVNA. I used recycled plastic gum boxes as enclosures and winders for the un-uns and wires. I also 3d-printed a winder that holds the transformer and heavier speaker wire. I’ll test the antennas when bands are obviously better. I’ve not really used an EFHW much, so I’m curious to see how it performs compared to EFRW.
  • I saw some recovery today in the band today: Panama, Canary Islands, and the Cayman Islands.
  • Ron, WA3VEE, sent photos from the Antique Radio Meet in Kutztown.

My Question for the Night

What are the effects of solar cycle and solar activity on propagation? We’re in a high point of the solar cycle, so 10m is good, but too much and it blacks out propagation?


  • Vic, KC3TYX, made a VARA-C contact.
  • Jim, KC3RFG, found an OCF dipole to be quieter than end-fed.
  • Jim, AF3Z, has trouble with his Ten-Tec radio sometimes not transmitting.
  • Jeff, W3JAM, wondered if anyone was making 6m contacts over solar storm.
  • Mike, W3MFB, noted that 17m sometimes is a pipeline right into Florida in afternoon/evening.
  • Tim, W3QP, is headed on SOTA campout.
  • Jack, K3YVQ, Is it OK to use GMRS on a radio that does ham freqs and more?
    • Mike, W3MFB: technically, the radio should be locked to gmrs frequencies.
    • on the air, no one would know, though.
    • Ron, WA3VEE: FCC approves radios for particular services.
    • GMRS radios are “type-acceptance”, and the right power limits.
    • Some other radios might be hard to limit to the right power.
  • John, KC3WWC: What’s the solar storm do to propagation? Some activity is OK, but too much is bad?
    • Chuck, NA3CW:
      • RF is produced by accelerating (“wiggling”) electrons.
      • Ionosphere doesn’t “bounce” signals, but instead “receives” and “retransmits”.
      • We have loose electrons in the upper atmosphere, good for retransmit.
      • Solar storm ionizes the atmosphere at different levels with varying intensity.
      • Our RF hits ions in lower part of the atmosphere and gets slowed, absorbed (D layer).
      • LF is affected the most, since it moves the electrons further.
      • Solar minimum offers less ionization at any level.
      • D layer, E Layer, F1 layer, F2 layer.
      • Better shortwave propagation at night.
      • Lots more is understood now about the ionosphere.
      • Frequencies are coordinated in SW to adapt to seasonal changes.
      • Electrons free in thicker air recombine more easily, so don’t pass RF.
      • Winter: great distances, because air is thinner.
    • Tim, W3QP: noise also comes up during storm and masks signal.
    • This video from Coastal Waves and Wires explains the effect a bit.

New Wires

The bands were dead with the terrible geomagnetic storm this weekend, so HF is very limited. I was only able to contact Lititz from Mountville.

With the downtime, I built some new EFHW antennas. I tied some wires to trees, stretched them out, and tuned each of the 2 20m EFHW antennas with the NanoVNA: one speaker wire, and the other lightweight silicone wire. I built new ununs and mounted them in plastic gum cases and a 3D-printed winder.

I also cut a lightweight EFRW, 12.5m, from the silicone wire and gave it a gum case as a winder.

I’ll test the new antennas soon when the bands are better.

985 Workbench - 2024-05-06

My Week in Radio

  • Backyard antenna
    • build
      • cleaned up the backyard
      • threw wires high in the tree near the top of the hill
      • took my time
        • routing
        • tied and supported solidly,
        • no stress on connectors
      • first floor window to high on the hill
      • the hill is to the east
    • testing, discussion last week
      • made some contacts on 30m
      • switching
      • FT8 on 15m and pskreporter
      • counted decodes in wsjtx
      • new antenna had fewer decodes on average
      • compared the map - missing europe, since it followed the hill and not enough of the antenna is above the ridge
      • old antenna is mostly flat, but is 2nd floor and above
    • scheme to get more of the wire higher
  • Reading the manual for fldigi
    • better prepared for contesting and logging
    • less fixing logs
  • Observing some very boring HF propagation
    • if it weren’t for the propagation reports, I’d think I broke something.
    • leaves also came in on my antenna tree


  • Tim, W3QP, talked about sota.
  • Ron, WA3VEE, is helping a new operator shop for equipment.
  • Ron’s going to the antique radio show to sell.
  • Leon, AA3LH, is practicing CW.
  • Jeff, W3JAM, why do we conventionally use LSB and USB?
  • Bill, KC3OOK, does internet time sync work through hotspots?
  • John, KC3WWC, What are better interfaces to SOTA?

Backyard Alternate Antenna

I cleaned up the backyard a bit, and ran a new 12.5m (41ft) random wire up the hill behind the house.

My first tests the next day on 30m at 1W got me some contacts. By 4:40pm EDT, the bands were all in “poor” condition, so it got tough to test.

The next morning, I watched the 40m band close. It was ablaze at 8am, but getting pretty quiet by 10:30am EDT.

I compared the old antenna out the front with the new antenna out the back using FT8 and PSKReporter.

The back antenna saw fewer decodes on 15m on average. It mostly lacked any stations from Europe. Looking at the antenna’s physical attributes, it starts on first floor (lower than the old antenna) in backyard, but it slopes up more vertically. The middle of the antenna, on average, is blocked by the hill to the East.

The old antenna out the front saw more decodes overall, including Europe. It starts at second floor window and only slightly angles up. The whole antenna is higher and clears the hill, even though Europe may still be mostly all the end of the antenna. It performs better.

I had fun physically launching the new antenna, but I’ll need to do some more work to get more of it higher in the air to be useful.

hf  antenna  ft8 

Spin 30m

I spun the dial below the 30m ham band at the end of the night, and I caught all kinds of interesting broadcast (31m) and HF air traffic.

30m  swl  hf 

985 Workbench - 2024-04-29

My Week in Ham Radio

  • Built and deployed a 1/4 wave ground plane with radials
    • wire soldered to an UHF chassis plug
    • fed from the bottom
    • hung in a tree by cord
  • York Hamfest and 2 parks out that way
    • Codorus
    • Sam Lewis
    • EFRW
    • Mostly ft8
    • 40m hot at 5:30pm
    • 2 phone contacts in Canadian parks for park-to-park QSO
    • Took some time to experiment a little
    • Fishing pole mast with 3D-printed fork on the end to catch the wire
    • Stop pulling on coax…loosened ends
  • SPDX RTTY contest (Poland)
    • 2 contacts
    • ended at noon UTC on sunday, so ran out of time
  • AubsUK firmware for Quansheng
    • 10 scanlists
    • automatic scan on power-up, feature request
  • Picked up a new podcast: Ham Radio Workbench
  • Simplex Net: heard 16 of the 38 people

My Questions

  • with nicer weather and time to experiment with antennas, how would you recommend iterating and experimenting? I have:
    • the QRP transceiver
    • digital modes & pskreporter
    • nanovna
    • some modeling software I could learn
    • the latest ARRL Antenna Book


  • Dipoles, sloped or flat?
    • Flat leaves nulls toward the ends
    • Sloped fills it in to be a bit more omnidirectional
    • An antenna close to the ground is going to be NVIS
    • Vertical is omnidirectional
  • Ron’s seeing infinite SWR on the “screwdriver” antenna.
    • Others have had problems as well.
  • Mike wonders about viability of using 6m FM in his area
  • My Question: How should I evaluate and structure my experiments with antennas?
    • Conditions change constantly
    • Learn to read solar data
    • Take notes on conditions and try to test in similar conditions
    • Vic’s experiments:
      • endfeds
      • hamsticks
      • radials
      • aluminum screen or faraday cloth for ground plane
    • WSPRnet and pskreporter help gauge how you’re getting out
    • See what you can hear
    • Qualify callsign for different tests, so I can tell them apart in pskreporter: kc3wwc/a, kc3wwc/b, etc
  • Ken wonders about TNC for packet radio on HF/VHF
    • Glenn, N3MEL would be the person to contact
  • We heard lots of interference and doubling in the beginning of the net
    • This was likely another manifestation of intermod
    • Tropospheric ducting happens more in morning in the summer