985 Workbench: 2025-03-31

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

POTA US-1418: 2025-03-29

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.

UV-Pro Firmware

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.

uv-pro  btech  aprs 

21 Lunch: 2025-03-27

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.

Fixing the De-tuned Slim Jim

The slim jim I put up for APRS was hanging right next to the feed line of the higher quarter-wave antenna I use for local analog traffic. The feed line was de-tuning the slim jim, so reception of APRS traffic was almost non-existent. I could swap the antennas and the higher one worked much better, and the lower slim jim was greatly degraded for other FM traffic. Usually the BTech is on the lower slim jim, and the Quansheng is scanning on the higher quarter-wave.

To correct the problem, I pulled the 2 antennas up on separate ropes and separated them by a couple feet. The quarter-wave is still mounted higher than the slim jim.

985 Workbench: 2025-03-24

My Week in Radio

  • 985 breakfast
    • chatted lots of Vic and Jerry
  • pota
    • 2 parks: middle creek and state game land down the road
    • set up multiple antennas: efhw + tactical delta loop
    • telescoping antenna for CB walkie talkie
  • observed some degraded propagation the next day or 2 over the weekend
  • need to check and tune up my slim jim again

Questions

  • KC3TYX, Vic: Tried to tune into WA3KFT’s 6M net, but could only hear 1 person. What kind of antenna should he have used for local contacts like that?
    • W3MFB, Mike:
      • PVC pipe with caps and made a rigid half-wave dipole and put it on a lightweight rotor to change direction of the horizontal broadside.
      • try an omni-angle antenna (circular)
      • you may also hear better in the summer.
    • WA3KFT, John:
      • used 2 perpendicular wire dipoles thumbtacked to the ceiling in an apartment.
        • single feed point
        • omni-directional
        • feed directly with coax
        • VHF frequencies have smaller antennas
        • thicker elements give wider bandwidth (copper pipe)
    • KC3SQI, Wayne:
      • built one that looked like a hula hoop: folder 6m dipole in a loop
        • omnidirectional + wide bandwidth
        • he can lend it
    • WA3VEE, Ron:
      • double bazooka design
  • WA3VEE, Ron:
    • What’s the minimum to deploy in the field for HF, VHF, UHF?
    • KC3TYX, Vic:
      • radio, hamstick, battery
    • W8CRW, CR:
      • just his truck: it has everything for UHF, VHF, HF.
    • KC3YSM, Steve:
      • looking at plans for simple wire antennas.
        • KB9VBR pota performer on a camera tripod with elevated radials
        • going to try to build that one
    • WA3KFT:
      • handful of hamsticks
    • W3MFB, Mike:
      • for emergency in car: UHF/VHF radio, CB, G90, some hamsticks
      • tune anything with a G90

Breakfast and POTA

I went to the 985 breakfast and chatted lots of Vic and Jerry.

After breakfast, I hit the parks for some POTA. I started at Middle Creek where I tested my EFHW vs the Tactical Delta Loop.

Next, I setup at State Game Land 156 down the road with the telescoping antenna for a CB walkie talkie.

pota  efhw  tdl  antenna  hf 

SPARC Meshtastic Channel

I had created a channel on my Meshtastic node for SPARC and at the Elmer night, we signed people up to use it.

Name: SPARC
PSK: WVaaYi2B/GJWGJwgbyXH7+na142aLwend1+UA2W2CPo=

ATU Bug in R1CBU 2.29.2

I encountered a bug using the ATU on R1CBU 0.29.2. I had lots of tunings very near each other, so it switched a lot. It queries and uses the nearest tuning to current frequency, so lots of close tunings will cause thrashing as you move. I cleared the atu table in params.db to alleviate the problem for a bit.

r1cbu  atu  hf  x6100