My Week in Radio

I managed to get my 107-ft random wire a little higher in the tree before the leaves fully filled in. I also made some CW contacts in the 7-zone QSO Party and the Delaware QSO Party.

My Question

I’m contemplating an even longer wire for my antenna setup: an 80m EFHW, totaling 40M in length. I’m wondering if there are any downsides to this, such as a weird radiation pattern or needing more power.

• NA3CW, Chuck: Suggested that at certain lengths and frequencies, the antenna might start firing off the end of the wire.
• AA3LH, Leon: Shared his experience with a 135ft dipole, which he uses on 10, 20, 40, and 75 meters. It’s fed with 30ft of ladder line, 25ft of coax, and a 4:1 balun, and he says it works great. Consider a dipole with 600ohm ladder line.
• KC3NZT, Harvey: Recommended using a 9:1 unun for a random wire and looking into a resonant end-fed antenna. He also mentioned using an AH4 tuner at the wire and that a resonant antenna would be more sensitive. He suggested switching to a 49:1 unun.
• KC3RFG, Jim: He went from a 49:1 to a 71-foot end-fed long-wire with a 9:1 unun and found the 71-foot to be quieter. He also mentioned a 53-foot wire and that super-long wires can receive a lot, but also a lot of noise.
• KC3SQI, Wayne: Check the udel.edu for information on random wire antennas. He pointed out that as you extend the wire too far, you get too many harmonics and the antenna can become imbalanced. Palomar ununs are among the best.
• AF3Z, Jim: Consider what bands I want to use.
• KC3WWC, John: Is familiar with the 40m EFHW and is going to try a 80m EFHW. It’s encouraging to hear that the EFHW may offer better receive performance. I’ve used UDEL’s site for non-resonant lengths and will switch to a 49:1 for the EFHW. I’m also considering whether his 71ft EFRW was better than 107ft, noting that conditions probably changed.

My Week in Radio

• I’m using Allstar to avoid intermod.
• I added two more parks to my POTA list in Las Vegas. During my operations, I ran between 2-4W and made contacts with Brazil, Belize, and many stations on the East Coast. I primarily used digital modes but also tried some CW.

Others

• W3JAM, Jeff: Took down many antennas from his roof and is starting over with his shack setup. He might be unloading some gear and has an OCF dipole from Palomar Engineering ready to launch. He’s also building a large amplifier close to the legal limit.
• W3RJP, Bob: Getting started with Repeaterphone for Echolink.
• WA3VEE, Ron: Noted that a two-day hamfest is approaching. The Pottstown club is very welcoming, and he encouraged joining them this Friday night. Claymont has a VE session on Saturday, and Sunday will feature the Warminster hamfest. Last Saturday, at the DE hamfest, he met some high-schoolers from Felton, DE.
• KC3SCY, Luke: Listening to W1AW for CW practice. He observed that 10M is bad, and he’s restoring an old steel-wheeled wheelbarrow he found in the woods.
• KC3RFG, Jim: Experimenting with a magnetic loop in his yard. He upgraded to an aluminum loop, finding it more efficient on 10M but less so on 40M. Using his G90, he made a very strong contact with the Galapagos Islands.
• WA3KFT, John: Used 100W to break through intermod. He has a 2M 1K amplifier available for sale and is testing a Comet antenna.
• W3MFB, Mike: Testing a new radio in a new location.
• NA3CW, Chuck: Participated in the AMA PM net and is setting up a new Linux computer, having figured out how to transfer files between virtual machines.
• KC3OOK, Bill: Engaged in some regular nets and is continuing to build out his ham shack.
• AF3Z, Jim: Did CW at Cornwall Station and is practicing CW. Has an Astron linear 50A power supply, which weighs 47lbs.
• KD3AIS, Tim: Launching his EFHW for HF work with help from a neighbor.
• KC3TYX, Vic: Participated in various nets.
• W3QP, Tim: Is back from New Zealand, where he activated 20 summits (including Mount Doom) and made a 40M contact to France from NZ.
• W3DIB, Greg: Is running 100% Arch Linux.

Questions

• W3MFB, Mike: What are others’ experience with ground-mounted verticals for HF? What sizes, transformers, radials? Can it be on a tilt base? Is guying is necessary if they need a mast?
  • WA3KFT, John: At an old house, he drove a pipe into the ground next to a patio and used a cheap vertical with a loading coil, which was simple but single-banded unless multiple taps were used. His current 80M-2M vertical in the yard is multiband but a compromise.
  • KC3SQI, Wayne: Uses a random wire vertical for POTA, consisting of a single wire, radials, a 9:1 unun, and 35 feet of wire.
  • NA3CW, Chuck: Verticals in forests lose efficiency.
  • KC3WWC, John: Similar setup to Wayne’s: a 25-foot Rybakov antenna with a 4:1 balun.
  • AA3LH, Leon: Uses an Eagle 1 antenna, which is ground-mounted, has no baluns, uses radials in the grass, and is 40 ft tall.
  • KC3SQI, Wayne: Suggested loading up aluminum downspouts but noted the need for isolators to compensate for aluminum siding.

My Week in Radio

• I spent some time patching the open-source firmware for my HF radio. The original modification aimed to center and save the ATU network on the current frequency, which is effective for about 25kHz in either direction. The system saves the tuning network settings into both a cache and the database. However, it needs to update nearby saved tunings. I noticed the radio would click in new tuning networks within 1 kHz of each other. After digging into the code, I found the error in how it cached these networks.

• Unfortunately, intermod hits every Monday, so I had to jump to Allstar, even though I had tested RF earlier in the week.

Others

• WA3VEE, Ron: Discussed the Mud Mosey event.
• W8CRW, CR: Also mentioned the Mud Mosey.
• AF3Z, Jim: Had a CW sked.
• NA3CW, Chuck: Noted that the Mud Mosey operation sounded really good. Also discussed the AMPM net and propagation.
• KC3OOK, Bill: Participated in the Mud Mosey. Ron ran a net for people on their way in and out of the Mud Mosey service. Bill also served as net control for the simplex net and conducted a round table exercise to experiment with simplex.
• KC3YSM, Steve: Participated in the Mud Mosey for his first service operation.
• KC3NZT, Harvey: Listened to the roundtable.
• W1RC, Mike: Nearfest is coming up soon.
• AA3LH, Leon: Was on 10m last Tuesday, getting a 599 to Oregon, but then the signal dropped off completely. Later, he got a 599 to Los Angeles, but it also dropped off.
• KB3ZIM, Bob: Lots of mobile radio activity. Recent Chester County ARES/RACES meeting discussed revival of packet radio.
• KC3YIG, Dave: Struggling with building a vertical antenna.

Questions

• AA3LH, Leon: If flat straps are recommended for grounding, would they also be good for a counterpoise?
  • WA3VEE, Ron: Flat straps control inductance. An electrical ground is fixed, but a counterpoise is often deployed and redeployed in the field, making it hard to keep flat.
  • KC3NZT, Harvey: Probably makes no difference. He used a strap in his car because it’s cheap, and he’s used cheap wire shelves in the grass as a ground plane for a vertical, attaching to it with a strap.
  • AF3Z, Jim: Brought up the skin effect, where RF runs on the surface, not the middle. A strap may provide more surface area for RF.
  • NA3CW, Chuck: Frequency affects the depth of the skin effect. DC uses the entire conductor, 60Hz uses almost the entire conductor, but on VHF/UHF frequencies, it will stay in a copper coating on aluminum (like in LMR400).
• KC3NZT, Harvey: Are there any FCC issues with recording and replaying as a relay, especially for emergency communications (EmComm).
  • WA3VEE, Ron: ARRL started with “relaying” and that he records and plays back to demonstrate reception, so it should be fine.
  • NA3CW, Chuck: Advised to just be careful not to sound like you’re identifying as the other station.

I encountered a bug with the ATU in the X6100 running R1CBU firmware version 0.29.2.

The ATU networking information is stored in both a cache and the params.db file. When setting multiple tunings close to each other (e.g., 7073, 7074, 7075 kHz), the radio would rapidly cycle through them as the VFO was spun. This behavior cluttered the configurations and made it difficult for the ATU network to hold a stable tune near a signal.

Upon investigation, I discovered that while the cache retained all these closely spaced tunings, the params.db only saved one of them. The intention behind the new feature in R1CBU was to remove the hard boundaries between ATU configurations (which were previously every 25 or 50 kHz), allowing a single tuning network to be effective within approximately 25 kHz in either direction. The database would correctly update a nearby frequency to the middle, but the cache’s retention of every tuning caused the “thrashing” effect. Switching antennas or cycling power would reload the sparser collection of networks from the database, temporarily resolving the issue.

I filed a bug report, and submitted a pull request to fix it.

I patched the ATU code to reload the cache from the database immediately, effectively discarding the extraneous nearby networks.

Rain was predicted later in the weekend, so I headed out to Marietta Riverfront Park (US-4567) for a quick activation to beat the rain. My initial plan was to rebuild my EFHW antenna, but I cut the new wire six inches too short, and I didn’t have enough wire on the spool to start again.

I opted for my 12.5m EFRW instead. It was 7 PM, so I focused my efforts on the 40m. I successfully got about 18 contacts before I packed up for the evening.

My Week in Radio

• I have a blog of my radio notes, but I’ve fallen behind by over a month in posting.
• Tested a rybakov antenna with 4:1 balun and 25-foot wire out at a park.
• Btech UV-PRO (for APRS) has been seeing lots of beta firmware updates
• Attended a lunch with a Harrisburg 21 repeater group to learn about beacons and online tools for radio conditions
• My second 2M antenna (slim-jim) was performing badly
  • hanging next to the feed line of the higher antenna, and it was completely de-tuning it
  • pulled it up into the tree on its own line to provide space
  • still hangs lower than the other antenna to avoid interference
• contestcalendar.com has a google calendar feed, which i’ve imported to my calendar, so no more date math to figure out UTC

Others

• W8CRW, CR:
  • updated phone software, so allstar node is working.
• W3JAM, Jeff:
  • on digital to avoid connecting to anything on the roof in the storm
  • simplex net from the shack
    • always observing conditions on 2M
    • ducting
    • heard lots of distant stations, but not close
    • worked 50 miles across lancaster county
    • switched between vertical and horizontal: horizontal was better sometimes
    • new diamond antenna to install
    • swapping out everything on the shack
• NA3CW, Chuck:
  • hosting AWA pre-net
  • working on Joe’s tuner project: crimp connectors for components
• KC3OOK, Bill:
  • out in the truck to operate in the weather
  • mobile simplex net, south control
    • copied all but maybe 3 stations
• KV3JGB, Matt:
  • new parts, a choke, for the HF radio
• AF3Z, Jim:
  • visited a friend’s barn of parts for 1929 hartley oscillator
  • triton 4 didn’t turn on for CW sked: bad power supply, so switched to battery
• WA3KFT, John:
  • 100W RF to get through
  • new bracket on the tower
  • modifications for being able to tilt down the antenna.
• WA3VEE, Ron:
  • testing an IC-9700: working nicely
    • right on frequency
    • no harmonics
    • full power on every band
    • all configured
  • mud mosey for those helping, April 12, contact KC3TMT for info
• AA3LH, Leon:
  • back from weather events
  • in trailblazer, installed a new dual-band VHF/UHF radio
  • ran some 2M nets, but missed simplex net
  • 80M: rooster net and bible study net

Questions

• AF3Z, Jim:
  • AICO audio generator:
    • 2 tubes, precision resistors
    • wein bridge oscillator
    • siren like, but it varies on 15 second interval
    • what component failure causes the variation
  • WA3VEE, Ron:
    • check for a ripple from the power supply
    • sounded like a beating with the output
    • warble may vary with frequency
    • wein bridge oscillator was the first product of hewlett packard
  • WA3KFT, John:
    • check B+ voltage from the power supply and at the tube
  • NA3CW, Chuck:
    • looking at the schematic
    • uses a lightbulb to stabilize based on temperature
    • check the tubes and check that lightbulb
  • WA3VEE, Ron:
    • the lightbulb may not light, but it’ll use cold resistance of the tube
    • check continuity
    • if the power supply is giving ripple, the capacitor is bad

I setup at US-1418 for an activation. I tried to setup the 40m EFHW in a nearly vertical configuration, but my throw wasn’t high enough, so I went for a vertical 25-foot Rybakov instead. I used my 4:1 balun.

I got my activation working 10M and 15M FT8.

I’ve been learning about the BTech UV-Pro. When scannimg, it degrades the incoming APRS, even in digital mode where it checks back to the APRS channel frequently. I’ve been using stock APRSdroid over the TNC connection, but it takes a little fiddling sometimes to get it to connect.

In the new firmware, they’ve been flip-flopping features between 8.2.x and 8.3. It has bold/yellow fonts (or not), and new button actions to access groups. NOAA alerts have also come and gone to see if they affect RX performance overall.

Beacons and Online Tools to Predict Propagation

• Presented by Greg, K3EA
• RBN
• Pskreporter
• WSPRnet
• VoaCap
• Watch for openings on calling frequencies
• ARRL band maps
• Hamalert
• Hamclock
• DX clusters

A side note: SMRA hosts great presentations, so check them out some time.

I always keep a tab open to the Contest Calendar, but I discovered they have a feed for Google Calendar.