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

See also