SDRplay Community Forum

Preliminary tests of front end High Pass filter I enclose two comparisons of reception with and without HP filter on 40 and 20 m. These have been done with a makeshift 15 m long wire antenna and a water pipe ground while on a flat in a sea resort, so they are by no means definitive, but give some i...

Hi Mark,

Herewith uploaded same table as in previous post, but for frequencies ABOVE 30 MHz....

Cheers,

glovisol

Hi Dick, Just to clear confusion I am enclosing the table showing the relationship between "S" units and received signal strength (power) in dBm. As far as my experience goes, with the RSP2pro and with the RSPduo, the "S" units shown on the meters correspond to the received dBm with faultless precis...

Hi Martin, I have carefully gone over the literature you suggested and these products are of very good professional quality for receiver sensitivity measurements and for this use they have output levels in the order of -90 dBm. My question is as follows: do you know of any supplier who markets a muc...

Application of the high pass noise filter to build a balanced input for the RSP1A, as anticipated in the previus post. This scheme allows for best ground separation. One side of the balun's input is connected to the antenna's ground. Connection between antenna and balun may be also done using a bala...

It looks very unlikely to me that water among USB terminals could damage the RSP2 USB interface, unless you were drinking salt water. You should check the laptop PSU for possible mains leakthru to laptop's common ground, also extremely unlikely. I would open a ticket with SDRplay tech assistance: it...

The post by Nulluser00, who dug up very interesting technical information on antenna transformers, gives me the opportunity to further comment on the relationships among: - low noise coupling between antenna and receiver, - wide band coupling between antenna and receiver - receiver's dynamic range a...

High pass n = 6 calculated filter performance is shown below. Attenuation in blue & return loss in red.

The advantages of the high pass noise filter can be extended to receivers equipped with the 50 Ohm input only. The uploaded schematic is for an umbalanced 50 Ohm input / 50 Ohm output. Balanced antenna input can still be achieved by placing a balun at the filter's input and isolating the grounds, as...

Hi Martin,

Please accept my compliments and thanks for your most interesting and informative post. You opened up a vista on available noise and measurement devices completely unknown to me and probably to many others using this Forum.

Thanks again,

glovisol