After fiddling with the graph function I added a “trend” line that fits very nice onto the trace of the measurement. Therefore the bent signal reduction line on the screen appears quite linear! Using the CSV export function I exported the trace information to Microsoft Excel. Luckily I updated the firmware of the : Rigol DSA815-TG spectrum analyzer and has now the option to show the frequency scale logarithmic instead of linear. The lower the frequency, the more the signal reduction at the test point and vice versa. The signal reduction of the test point is logarithmic. I would expect the signal reduction is linear, but I was wrong. I normalized the test setup and measured the loss. And since I bought a : Rigol DSA815-TG spectrum analyzer recently, this is a nice opportunity to determine the power reduction at the test point.
The dummy load is used for seven years now. I guess the chip resistor can handle at least 100 Watts of RF power when fitted to a heatsink. The RF power is dissipated into the chip resistor and a relative low power test signal can be used to feed a frequency counter. This is for example convenient for frequency measurements. The internal chip resistor has a test point which is connected to the BNC socket. The nice thing about these dummy loads it equipped with a BNC test point. Possibly the dummy load were used to dissipate sideband energy... The footprint, paint color and structure and four holes of the dummy load match perfectly to the unpainted square on the front of the RS460 filter boxes. It’s likely these dummy load were fitted to the front of the : RS460 cavity band pass filter. It’s a dummy load from the former NMT450 mobile phone network. Commercieel gebruik of verdere verspreiding is niet toegestaan.ĭit is de afdrukbare pagina, klik hier voor het artikel op de volledige website.Ī long time ago I bought a Radio System AB (Ericsson) 50 Ohms dummy load with N-connector for testing purposes. Radiosystem AB dummy load > ĭeze pagina mag afgedrukt worden voor thuisgebruik.