![dsa815-tg frequency counter dsa815-tg frequency counter](https://i.ytimg.com/vi/xrsXzRsvmgg/maxresdefault.jpg)
If a frequency in MHz is multiplied with 7,527 and the result is reduced with 72,44, the answer is the signal reduction in dB relative to the input.įor convenience I calculated the signal reduction for the regular ham bands. Since the trend line fits very well it’s safe to say that the formula fits therefore also the signal reduction. There’s a convenient option to show the formula of the trend line. 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.
![dsa815-tg frequency counter dsa815-tg frequency counter](https://rigolshop.eu/pub/media/catalog/product/cache/d635b94e0eddcd1cd17a6de4be3229db/d/s/dsa815-2_1.jpg)
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…
![dsa815-tg frequency counter dsa815-tg frequency counter](http://www.adinstruments.es/WebRoot/StoreLES/Shops/62688782/5463/454B/97F6/E8C9/E086/C0A8/2ABB/91EB/110A_EMC_probe_cable_large.jpg)
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. Informatie pagina voor experimenteel radio-onderzoekersĪ long time ago I bought a Radio System AB (Ericsson) 50 Ohms dummy load with N-connector for testing purposes. Please support this (commercial free) webpage by donating a small payment: Radiosystem AB dummy load > AMATEUR TELE.