My week in Radio
- I saw aurora for the first time, and I got some nice photos.
- I visited K3IR tower sight in Mount Joy during PA QSO party
- I listened to people contesting, but didn’t participate.
- TYT TH-9800: 50W into the tape measure yagi, tried it on the roundtable, still have work to do
- I threw my main 71-foot EFRW higher into another tree.
- I watched my flagpole and yagi in the wind
- walked it down while I had a kid here to help
- scoping a new location for it as a tilt-up attached to the house
- collecting pieces for some experiments in engineering
Questions
- W8CRW, CR:
- National Electronics Museum is hosting a class for general license.
- How far from the mast should a vertical yagi antenna be installed?
- Can it be installed 45-degrees to be used for both horizontal and vertical?
- WA3VEE, Ron: some have had success at 45 degrees for satellites.
- KC3SQI, Wayne: 45-degree will lose you 1.5dB
- WA3VEE, Ron: what is the ideal thickness for a bus-bar
to which you’re mounting a lightning arrester.
- KC3RFG, Jim:
- 1/4-inch minimum. thicker won’t hurt anything.
- mechanically strong (bolted) instead of soldered
- woven ground strap is best, but 6AWG stranded is good.
- NA3CW, Chuck:
- avoid inductance, so use strap or bar, not wire
- no right angles, no coils, no spirals
- KC3RFG, Jim:
- KC3RFG, Jim: Hearing ignition noise on HF on battery or on truck power.
How best can one eliminate that noise?
- KC3SQI, Wayne: Remove the mast from the coax and see if you still have the noise. If it’s still there, then it’s coming from power cables. Try a better ground directly to the battery. On vehicles that rust, bolts don’t ground so well after a while, so then you get lots of grounds connecting back through the antenna.
- KC3KZB, Aaron: go for a short ground, and keep ground wire away from ignition wires
- KC3SQI, Wayne: What’s the mechanical strength for 1.5-inch conduit?
- WA3VEE, Ron: See Ugly’s Electrical Reference.
- KC3RFG, Jim: that’s right.
- KC3WWC. John: I like that I can build my transformers and cut, measure,
and test wire antennas,
Is it practical to build, iterate, expand a homebrew yagi?
- NA3CW, Chuck:
- blatant plagarism: they’ve been around for a long time.
- modeling programs, manuals, existing antennas.
- different goals: gain, bandwidth, front-to-back ratio examples in the antenna book
- software
- moxon antenna: 2 element yagi with bent ends, massive front-to-back ratio
- great for direction-finding: forward to get in the neighborhood, then reverse to find the null where it disappears
- not much gain though
- NA3CW, Chuck:
- W8CRW, CR: Is there a program for windows to map out a computer network?
- W3DIB, Greg:
- there are lots of tools to probe and fingerprint machines to try to disclose the host OS.
- also ping, angryping, etc.
- W3DIB, Greg: