Quarter-Wave Ground Plane Antenna

I followed calculations and instructions to build a quarter-wave ground plane antenna from some wire and a UHF connector that I picked up at the last Ham Fest in Harrisburg. I cut everything a little long and soldered it together. I trimmed the radials to about 54-inches and folded and rolled the radiator wire to a length that is resonant at 147MHz. I measured with the NanoVNA. Once it was at the right frequency, I found that bending the radials up and down could adjust the SWR at its lowest point on the graph. Keeping the radials slightly flatter had a lower SWR than the 45 degrees suggested in the original design.

This ground plane antenna feeds from the bottom, which is physically more sound than the vertical dipole I had up previously. I tested it last night when I strung it up, and it reaches Harrisburg and Parkesburg with no problem.

antenna  2m 

SPARC Membership Meeting - 2024-04-23

Joined the Club

My membership was approved, so SPARC now has 146 members. Mark asked if I’m a climber. It sounds like lots of people chicken out about half way up when climbing the tower. When studying for my license, I didn’t commit a lot of the tower stuff to memory, since I didn’t expect to be involved in that sort of thing.

Ham Fest in York

SPARC will be at the Ham Fest in York with some “ham junk” for sale. Ralph, from Radio Shack, bought Souders’ small hardware business, so he’ll have all those small accessories there. Testing will be available at the Ham Fest on a walk-in basis.

Other Programs and Notes

  • Breakfast in Manheim, every 2nd Saturday, at City Star Diner.
  • Mike is building fox hunt transmitter. Someone else is building a battery for it.
  • Tech classes will start again, Maybe on Mondays. Someone suggested conducting a mock net for training.
  • UHF repeater is working. Full-time tied to VHF.
  • Field day is coming up soon at the club house.
  • There may be room for me to help with website maintenance.
  • Some people are going to Dayton Ham Fest.
  • Trying to use Ham Club Online again to manage membership. It’s a database for ham clubs. Ares is on it.
  • Balun Designs is a good source for durable hardware.
  • HFQso runs nets for testing propagation.
  • There’s an Appalachian Trail APRS Golden Packet event to pass an APRS packet the entire length of the trail.
  • Podcast: Ham Radio Workbench
    • An old episode (1 year ago?) had Vance, N3VEM, doing rocket stuff.
    • I’m never going to finish my podcast list.
  • I chatted with JJ, KC3QEH. I need to look into his POTA activations.

Club Net

I checked into the club net for the first time tonight.

Aubs Firmware

I’m trying out the Aubs 00.07 firmware on my Quansheng radios. It’s based on the latest egzumer, and so far has kept up-to-date, and it has its own plugin for Chirp.

It has some really cool features for scanning:

  • scan on start, a feature I requested of egzumer, but was denied by egzumer.
  • 10 scan lists. I organized mine as:
    • 1 = local repeaters and popular simplex
    • 2 = all simplex, Ham and GMRS
    • 3 = non-local repeaters and other listening
    • 4 = satellites
  • press * to lockout a frequency from scan.
  • fast scan like egzumer
  • frequency spectrum analyzer, but no memory spectrum analyzer like nunu.

This is my daily driver now on both my radios.

985 Workbench - 2024-04-22

My Week in Radio

  • I met some 985ers on Friday morning at the tailgate and breakfast.
  • I heard a bit of the ARISS mission talking to students last week
  • I have APRS working
    • UV-K5 running egzumer
      • VOX mode
      • Sensitive
    • Pixel 6 Pro
      • Volumes way up, nearly 100%
    • BTech audio cable
    • APRSDroid
      • AFSK mode
    • Saw decodes on the phone
    • Saw myself show up on https://aprs.fi map
  • Evolve 3 laptop is working with Linux completely:
    • network
    • sound
    • used it for a pota activation
  • Time to also slim down the go box for POTA as it’s gotten heavy.
  • 2m dipole in the tree working well for a couple weeks, so it’s time to change.
    • next: try building a ground-plane quarter-wave with radials
    • it’ll feed better from the bottom
  • Trying other firmware on the Quansheng radios
    • mixes of features I want and don’t want
  • W3FIS, Paul Ross, sent me a small box of some radio gadgets to explore
  • I’ve been seeing people recommend using a CW decoder
    • maybe try the decoder in my radio
    • get some practice keying, instead of waiting
  • York Hamfest is on Saturday

APRS

The Working Configuration

I’ve gotten APRS working with my current gear. I’m running my UV-K5 running egzumer 0.22.0 and VOX enabled. I set the radio volume pretty high, about 75%, and connected the BTech APRS cable and a USB-C 3.5mm audio adapter to my Pixel 6 Pro for an audio connection. The volume on the phone was set to nearly 100% volume. I ran APRSDroid in AFSK mode on the phone.

I watched for my position to show up on the map on https://aprs.fi/.

The Stuff That Didn’t Work

With nunu firmware, I needed to key it manually, but it worked. VOX didn’t work in the nunu 0.20.5, so I switch back to egzumer for working VOX.

Next Steps

I’ll next try to find an old phone to run the APRSDroid and try to use the Explorer QRZ-1, so I can dedicate some hardware to this project.

Revisiting Power Noise

When I first started with the X6100, I’d see some noise that buried real signals when plugged into AC power.

Running on battery was fine, and running on the external lead-acid 12V battery was OK too. For weeks, I used the battery to smooth the noise. I’d run an AC power supply in parallel with the battery and turn it up just high enough that I didn’t see noise in the waterfall. The battery smoothed the power.

I switched to a LiFePO4 battery, and I found the built-in charging circuit made it hard to balance input power and output power just right to keep it smooth.

I asked around on the X6100 mailing list and I got 2 suggestions I took:

  • a filter I can use with any cheap power supply I already have
  • a cleaner, and inexpensive, switching power supply from Ateck that puts out a fixed 12V/5A

I purchased both to try, and both helped immensely, each on their own.

I wired up the filter with some 5525 connectors and printed a case for it. I use the filter in combination with my adjustable 24V/5A power supply on the go. That higher-voltage power supply is also useful to charge the LiFePO4 battery at 14.1V. The battery also lives in my box for portable operation.

I use the Ateck power supply on my desk by itself to power the radio at home.

FT8 DX

The 40m band was hot at 5:30am EDT. I got:

  • Trinidad and Tobago
  • Dominican Republic
  • mostly eastern US otherwise

Switched up to 15m to get Finland, and I grabbed 1 local contact on 6m. I’ve accumulated 1800 contacts on QRZ, 1489 are confirmed, across 79 countries.

ft8  dx  hf 

SPARC Elmer Night - 2024-04-16

I visited the K3IR tower site for their Elmer Night. People were configuring cameras and testing an ultra-portable FT8 setup:

  • truSDX radio
  • ft8cn on a phone
  • very lightweight wire antenna and transformer kit
  • an inexpensive, but super-long, fishing pole as a mast

(Now I need one of those fishing poles.)

I borrowed a soldering iron and started on my own project: assembling a couple common mode chokes from a short piece of RG174. It got dark quick, so I finished the chokes at home. It was my first time trying to crimp those SMA connectors.

I got a quick tour of all the repeater hardware. There are a lot more services running on these towers than I realized.

985 Workbench Net - 2024-04-15

17 people attended the net.

My Week in Radio

  • POTA: Ridley Creek, east of West Chester
    • 21.56m efrw
    • embarrassing tangle of string, 30 minutes
    • got New Zealand!
  • POTA: Presque Isle State Park, Erie PA
    • eclipse
    • 21.56 efrw
    • operated next to my brother, kc3wry from the same picnic table
    • I worked 10m and he worked 40m
    • our data logs will be used my HAMSCI people, University of Scranton
  • Caught Pitcairn Island DXpedition, VP6G, on 5w FT8 10m.
    • operating shifted, and was super quiet
    • my first OC
  • Operating HT at 5W
    • dipole high in a tree
    • too sensitive for this cheap HT
    • FM bandstop filter to clean up the reception, especially for 985
    • TX though it without any fire!
  • Modified the database in my hf radio to mark the bandplan on the waterfall
  • started a website for all my notes since october

985 Breakfast on Friday

  • Lots of coax, antennas, analyzers, etc for sale.

Halyard on dipole install

  • AF3Z, Jim
  • Having a full halyard loop of rope to the pulley (like a flagpole) allows you to pull it up or down, whatever is needed.
  • Avoids having a pulley up the tree with no rope because an end gets away.

Dipole in the Attic

  • KCYYIT, Dave
  • Built the fan dipole for 6m and 10m in the attic.
  • Tuned it with nanovna
  • Not too tricky or ambitious: only the 2 bands.

Mud Mosey

  • Event at great marsh institute
  • Course marshals used gmrs ch 17.
  • 10 ham operators to help coordinate operations.
  • Used simplex freq 147.12MHz
  • Tom was net control

APRS

  • KC3YVQ, Jack
  • Does APRS kerchunk N3FYI?
    • We don’t think so. It should transmit and receive on standard 144.390MHz

Spectrum Analyzer for Travel

I drove out to West Chester yesterday, but I’ve not bothered looking up and adding repeaters for the area. Instead, I could set the spectrum analyzer on the UV-K6 (or K5) to scan the 145MHz-148MHz, stepping on 5.00kHz, and I had a pretty good picture of any repeaters to hear out there.

Once I heard something, I could pop open RepeaterBook on my phone and see what it was, but it saved me lots of trouble programming anything into the radio ahead of time to not necessarily need it.