Lab assessment of impedance mismatch of a UHF/SMA adapter-block

Since I’ve purchased Mini VNA Tiny, my first ever VNA analyzer, I have completely reconsidered all my beliefs around how cables, connectors and how impedance mismatches in general behave around the circuits. The situation, I noticed, is not as ‘innocent’ as it seems. Most recently, amongst many other cables, I have been measuring the loss of a very high quality Hyperflex-10 cable by Messi-Paolini. This is currently the lowest loss…

Kenwood TS-590SG Master Oscillator Drift and Warm Up

  A video for informative purposes, measuring the frequency drift of the master oscillator on Kenwood TS-590SG for 30 minutes after a ‘cold’ switch on. FLDigi was used to assess the audio frequency drift of the audible signal. Not shown on the video, is that the master oscillator was eventually settled correctly on the proper frequency after about 45 minutes on the receive mode. Perhaps, if someone was transmitting with…

Kenwood TS-590SG Reference Frequency Calibration (master oscillator tuning)

  Tuning of the local oscillator frequency on Kenwood TS-590SG. —————————————————————————————– According to the manual, the variable capacitor that needs to be adjusted is the TC501 (p.77 manual) and this is printed on the PCB, so it’s easy to locate it. Tip for variable capacitor: Clockwise: Decreases frequency. Anticlockwise: Increases frequency. Make VERY fine and slow adjustments, as the frequency is exceptionally sensitive to the capacitor rotation.

EAntenna balun (problems..) on the EA1015204080DXS fan dipole

After several weekends on the roof tuning without any success this antenna, I decided to take the choke away. Below is what the interior of the EAntenna balun looks like. It’s effectively a 1:1 current balun (not a voltage balun) also called choke, that is the inductors are in series with the coaxial cable coupled around the magnetic core and exiting at the dipoles’ entry point. After removing the choke,…

Review of HF SDR upconverter (design by SV1AFN)

This is simply a very effective and functional SDR upconverter. Since, you’ve reached this post, I presume that you are aware of the purpose of any upconverter: You simply take one RF band and you shift it up in frequency without changing any of the signal characteristics that it carries. Operation in brief: This upconverter collects signals from an antenna, it filters them with a 55MHz LP filter, it amplifies…