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 

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

York Hamfest and POTA

York Hamfest

I ran to York for the Hamfest and I saw a handful of new friends from SPARC and 985. I only bought some BNC adapters, a speaker that’s OK but not great, and a wireless keyboard/touchpad for my Raspberry PI projects.


While I was out, I figured I may as well play a little radio and activate 2 parks.

Codorus, US-1342

I ran the 12.5m EFRW stretched from high in a tree to a picnic table. I started at the picnic table, but moved into the car when it started to rain. To reach the car, I stretched my coax a bit and camped that to the table, and I ended up with no signal. The feed cable (RG174 with SMA connectors) had pulled loose from the SMA connector, so I had to debug that and push them back together. I operated 17m mostly, FT8, and contacts came a bit slow.

Sam Lewis, US-1418

This time I stung up the 21.56m EFRW, 2-3m off ground on ends, stretched between trees, and a fishing pole mast supporting the middle peak. 17m was still a bit slow, but 40m was hopping for FT8. I had a steady stream of contacts.

Before packing up, I spun the dial and found a park-to-park SSB on 40m: 2 operators on one radio at the intersection of 4 parks in Canada, so that counted for 8 hunter points.

york  hamfest  pota 

Ridley Creek POTA

We had some time in West Chester to visit Ben and see the new Mini Countryman, so I stopped by Ridley Creek State Park to activate. I had lots of tangles trying to toss my 21.56m EFRW into a tree – it took 30 minutes just to get started, but I had the wire at least 25 feet into the air. I operated FT8 and FT4 on 10m from a pavilion. [Read More]

Eclipse 2024

Matt and I ran to Erie, PA to watch the eclipse, and activated US-1402, Presque Isle State Park before eclipse. 10m was a bit slow, but I got there on FT8. I ran my 71-foot (21.65m) EFRW sloped up into a nearby tree from our station on a picnic table.

I got some audible screaming on the speaker in addition to the normal clicking when I hit the tuner. I usually have a choke near the radio, and that was missing.

It was cloudy and even some rain in the morning, but it cleared and we saw some blue sky before the eclipse started around 2pm.

Totality was at 3:16pm EDT. I have a video in 360 degrees.

985 Workbench Net - 2024-03-18

This Week in Ham Radio

  • I keep tweaking the outside 2m dipole
    • I got it a little higher
    • It tests different day to night
    • Signal is good then gone every so many seconds
    • Checked it for loose connections in the wind. It seems fine.
  • I’ve been learning to configure fldigi more
  • BARTG RTTY contest over the weekend
    • I finally successfully ran the frequency for a bit calling cq and getting responses
    • I stuck to the 5W QRP class
  • I’m scanning more frequencies for satellite repeaters
  • Weather is nicer, so I got out on my bicycle. It’s time to activate some parks (on the bike?). The Tram mirror mount for vertical antenna might clamp nicely to the bag rack.
w3gms  985  workbench  net  rtty  pota 

Day of Radio

ARRL/FCC/ARCC in Harrisburg

KA3TKW and the 21 repeater group hosted a lunch with representatives from the ARRL, the FCC, and the ARCC.


I stopped at State Game Land 246 near Middletown to activate on 10m FT8/FT4.

I used 2 different antennas: - initially used Grabil whip fully extended, shorted coil, w/ tuner - 12.5m EFRW thrown into a tree Both antennas seemed to perform similarly. I was skipping far: lots of contacts came from Oregon, Washington, and I even got Alaska.

Clipperton DX

Later that day, I also contacted the Clipperton DX station, TX5S, on 40m via FT8