Search found 662 matches

by glovisol
Thu Oct 04, 2018 12:56 pm
Forum: General
Topic: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
Replies: 13
Views: 7916

Re: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE

Analogous calculations, as shown in the example above, can be done to determine the optimum atteuation for any frequency band, for any environmental noise area and for any antenna type, depending on the decile evaluation of SDR system performance, as described in the relevant thread. For a long wire...
by glovisol
Thu Oct 04, 2018 12:38 pm
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 14520

Re: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF

5. ANTENNA DATA AND NOISE FLOOR EVALUATION The Noise Power delivered to the Receiver by a loss free antenna is equal to the flux density of the electromagnetic radiation impinging on the antenna times the antenna Effective Aperture. As will be shown in the Appendix, the Antenna Effective Aperture i...
by glovisol
Wed Oct 03, 2018 3:05 pm
Forum: General
Topic: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
Replies: 13
Views: 7916

Re: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE

Let us consider the following example at a frequency of 3.6 Mhz: here on the HI Z balanced input we have a Noise Figure of 11.4 dB derived from a measured Noise Floor Rnf = -130 dBm. With these values, the theoretical Receiver Minimum Detectable Signal: 12/10/2018 I have added in red colour the valu...
by glovisol
Wed Oct 03, 2018 2:49 pm
Forum: General
Topic: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
Replies: 13
Views: 7916

OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE

An immediate result of the performance assessment of the Receiving System, see: https://www.sdrplay.com/community/viewtopic.php?f=5&t=3685 is the availability of information which allows us to set the RSP Receiver up for optimum sensitivity and dynamic range in presence of noise. Table 1 of the prev...
by glovisol
Wed Oct 03, 2018 11:12 am
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 14520

Re: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF

Thanks Tech_Support, for your words of encouragement. In my last post, PART 4, I have changed the denomination of the antenna characteristic constant from k to r , otherwise there would be confusion between this constant and Boltzmann's constant shown in part 3, MATHEMATICS. Apologies for any inconv...
by glovisol
Tue Oct 02, 2018 5:45 am
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 14520

Re: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF

First of all there is a question of method. It is impossible to carry on a meaningful series of posts if you persist in posing problems at every step, so it becomes hard for readers to follow a complete tractation especially while my work is in progress. I politely did not complain, but what was the...
by glovisol
Mon Oct 01, 2018 2:00 pm
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 14520

Re: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF

4. ASSESSING ANTENNA DEPENDENT SYSTEM NOISE PERFORMANCE Revised 03/10/2018: Below I have changed the denomination of the antenna characteristic constant from k to r , otherwise there would be confusion between this constant and Boltzmann's constant shown in part 3, MATHEMATICS. Apologies for any in...
by glovisol
Fri Sep 28, 2018 8:55 am
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 14520

Re: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF

I could not agree more with what you say.....the point is I still have to complete this series of posts, as stated in my # 3 post... In the next post we shall see how to use the above expressions and tabled data. But I was diverted by your Noise Figure observations. The questions you are addressing ...
by glovisol
Thu Sep 27, 2018 1:20 pm
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 14520

Re: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF

MORE ON NOISE FIGURE ASSESSMENT Hi Roger, Concerning measurement of noise figure, I do not seem to be able to confirm the results of your proposed methods which would appear to disagree with each other and ask you to kindly help me. Here are my findings on my standard RSPduo. FFT method always with...
by glovisol
Thu Sep 27, 2018 6:13 am
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 14520

Re: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF

There are many methods to determine the noise figure of a receiver and they are all valid, provided they give the right result. For instance another practical method is to use a noise figure meter. The methods you propose give a noise figure of 15 dB @ 14 MHz. In my revised Table 1 (revised RX noise...