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RECEIVING SYSTEM ASSESSMENT @ 3.8 MHz Noise Floor assessment for the 3.8 MHz band is as follows: Wavelength Wl @ 3.75 MHz: Wl = 300/3.75 = 80 m Ratio L/Wl: R = 135/80 = 1.69 From "Beverage Antenna gain Vs. wavelength", Figure 1 in the cited reference: G = -2.5 dB referred to the isotropic. Balun in...

RECEIVING SYSTEM ASSESSMENT @ 1.8 MHz In this and in the following posts we shall use the data and information shown here: https://www.sdrplay.com/community/viewtopic.php?f=5&t=3685 to assess the noise performance in HF of an RSP receiver system equipped with the already described L=135 m Beverage ...

Hi Tech_Support,

The Noise Reductor works so well it made me curious on its operating principles....perhaps you could give us some idea on how it works.

glovisol

One week noise floor variation in Northern Italy. Data taken with already mentioned 135 m Beverage antenna at 17:00 local time (15:00 GMT) each day. This is not local noise, as verified by radio ham reports in QSO's, but a general situation, especially today, when a remarkable noise increase was reg...

As written in a previous post in this same thread, it is easy to damage the Noise Source BG7TBL if using a power supply voltage of 12 V DC or higher, even though the Source is rated for up to 15 V. For safety is best never to increase supply voltage above 9 V DC. In general what happens is that one ...

There is no problem with the RSPduo at 21 MHz. This problem has been solved once it was discovered that anything connected to the 50 Ohm antenna input (save for the 50 Ohm termination) would start the apparition of birdies spaced at 8 MHz, so this pointed to radiation from the PC laptop. Placing th...

Here below NR action documented at 1.8 MHz. Noise attenuation with cursor @ 200 is in excess of 14 dB. Lest someone notices an unbelivable noise floor @ 1.8 MHz, PC screens taken with RSPduo in operation with an antenna attenuation of 20 dB. The NR facility is of course useful with weak signals. Wit...

I suspect that the time lag shown by the NR to reach full action depends on the speed of the PC processor: e.g. the faster the PC, the shorter the time lag. This device is extremely good in suppressing noise: on 14 MHz, with a noise floor of -125 dBm an SSB signal at - 119/120 dBm (1.0 uV) on the HI...

It is very likely the PC you are using does not have enough speed and/or RAM capacity for supporting your RSP receiver. As a minimum guideline you should use a PC with a dual core 2 GHz processor and a RAM of at leats 2.5 GHz. With these minimum requirements you will be able to open just one VRX. Th...

The same problem with Tuner 2 as well. There is no problem of conditional stability when using the HI Z input. Tuner 1 and Tuner 2 50 Ohm front ends appear to be conditionally stable: e.g. amplification stability depends on amplifier's input termination. Probably a small input attenuator will provid...