2017-06-09, 23:39
(This post was last modified: 2017-06-10, 23:35 by radiofarol.)
today I installed the four digital lowpass filters. The noise floor droped from 110mV to 50mV, Which allowed me to raise the gain to 16X10 with no problem. I`m running in manual mode. I`m testing yet the best value for LPF tune, but seems to be around 50KHz. I have the LPF tuned in 25Khz and monitoring the spectrum but I can`t see advantage in relation to 50Khz. I have a lot of militar stations in VLF with very strong signals (about 75 or more dBuV) between 15KHz and 60Khz which occupy part of spectrum, but apparently without causing problems. I`m able to tune and measure this stations on my VLF receiver R&S EK070, with an R&S EH10 active antenna. I also took 4 outputs on the back panel to connect the oscilloscope.
I think the lowpass filters were a good investment, but I have to wait some more time to check the operation.
Station ID 1846
I think the lowpass filters were a good investment, but I have to wait some more time to check the operation.
Station ID 1846