Showing posts from January, 2020

Thunderbird Hamfest 2020

  Thunderbird Hamfest 2020 Filed in Operating on Jan.11, 2020 I always find good deals on test equipment on the West side of town. This year’s Thunderbird Hamfest continued that streak. I found an HP 3435A Digital Bench Voltmeter and an HP 5314A Frequency Counter at a reasonable cost (Total of $25 for the two). They are both functional.   HP 5314A Frequency Counter Also found was a 3456A Digital Voltmeter. This caught my eye because it has a 4-wire resistance configuration. I tested the Frequency Counter first. With approximately 65 Mhz input from my 8540B Signal generator, it read right on, with a little more precision than the 8640B can display. I cranked the frequency from 500 Khz to 130 Mhz. The 130 Mhz was the upper limit of the 100 Mhz rated counter. I already have a nice 100 Mhz counter, but wasn’t sure of the range of this new one when I bought it. I was hoping for a 300 Mhz or so, but that’s ok. The price was right. Period appears to

Nano_VNA Testing

  Nano_VNA Testing Filed in VNA on Jan.02, 2020 This year, one of my Christmas presents was a Nano_VNA (Vector Network Analyzer). These are like an antenna analyzer on steroids. You can check the SWR of your antenna through a range of frequencies, and get detailed information about the antenna impedance, including whether it is inductive or capacitive at a given frequency. This information is useful in developing matching networks for your homebrew antennas. The Unit has the additional capability to inject a swept frequency range through a device and detect how much gets through the output of the device under test. So it should be great for sweeping filter networks (Low Pass, High Pass, Band Pass, Notch, etc…), as well as cavity filters used in repeaters. The Nano_VNA covers all frequencies between 50 khz and 900 Mhz. That is a pretty good range, and covers the VLF bands, all of the HF bands, 2 meters, the 220 Mhz band and the 70 cm band. Just to get fami