Search found 662 matches

by glovisol
Thu Sep 27, 2018 5:57 am
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 13223

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

You can edit your previous posts (after logging in) by clicking the pencil icon as shown below..... edit.PNG edit.PNG (7.5 KiB) Viewed 18 times If you look carefully at my corrections, you discover that in general all posts can be amended as you propose and as I always do, SAVE FOR THE VERY FIRST P...
by glovisol
Wed Sep 26, 2018 7:50 am
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 13223

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

Since it is impossible to amend my #1 post, I upload the corrected PART 1 below. I have also amended the measured values in PART 2 above. 1. RECEIVER NOISE FIGURE FROM TERMINATED NOISE FLOOR Table 1 shows HF noise floor readings of my RSPduo receiver, S/N 180602D532 with the HIGH Z input terminated ...
by glovisol
Wed Sep 26, 2018 6:57 am
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 13223

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

Roger's observation is correct. The noise floor shown as a baseline on the receiver's dispaly is the dbm value of internal or received noise calculated on the total FFT bandwith : on Roger's screen this is 47 Hz on 3.08 MHz. The value shown on top of the display: - 126.9 dBm is the value of the nois...
by glovisol
Wed Sep 26, 2018 5:36 am
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 13223

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

Hi Roger, Since you do not specify whether or not your RSPduo is connected to an antenna, I presume it is not connected in your measurement and that the balanced HI Z input is terminated with 1 KOhm. My noise floor readings are taken, as to be expected....on the noise floor, by reading the mobile cu...
by glovisol
Mon Sep 24, 2018 9:34 pm
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 13223

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

3. MATHEMATICS The following development is based on the already cited Recommendation ITU-R P.372-13. The noise power generated by a resistor at the standard reference temperature of 17°C (To = 290°K) over a receiving system noise bandwith b = 1 Hz is calculated by the expression: Pn = k*To*b [W/Hz...
by glovisol
Sun Sep 23, 2018 7:05 pm
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 13223

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

2. PREDICTED ANTENNA NOISE FLOOR It is general knowledge that when you connect an antenna to the receiver’s input the receiver’s output noise significantly increases because it detects the noise picked up by the antenna. This noise is the composite result of the following: - Galactic noise from the...
by glovisol
Sun Sep 23, 2018 7:22 am
Forum: General
Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
Replies: 24
Views: 13223

ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF

ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF The maximum achievable signal-to-noise ratio (SNR) in any receiving system is fundamentally limited by the receiver’s noise floor. In low-frequency receiving systems–typically frequencies at and below High Frequency (HF)—the realized SNR is ...
by glovisol
Wed Sep 19, 2018 10:01 am
Forum: General
Topic: 2 RSP2s or 1 RSPDUO
Replies: 1
Views: 1206

Re: 2 RSP2s or 1 RSPDUO

One of the reasons why the RSPduo has been designed is to obtain the ability of effective diversity operation with suitable software, which is in development now. Literature is generally available on this subject.
by glovisol
Sun Sep 16, 2018 2:17 pm
Forum: General
Topic: HF weak signal reception in presence of noise
Replies: 10
Views: 5311

Re: HF weak signal reception in presence of noise

Quite by chance I found confirmation on my findings in this very interesting article: http://www.ab4oj.com/icom/dbmheaven.html Using an SDR play receiver the "low noise" procedure I use is simpler, as it consist in just manualy controlling the RF and the IF AGC. The RSP duo is ideal for this operati...
by glovisol
Wed Sep 12, 2018 3:23 pm
Forum: General
Topic: REMOTING RSP VIA USB - PROBLEM SOLVED
Replies: 2
Views: 2775

Re: REMOTING RSP VIA USB - PROBLEM SOLVED

Hi Noel, I have no intention to be drawn into an endless discussion about feedline grounding dangers, methods and concepts, while my original post is about the possibility of USB remoting the RSP receivers. We all, by the simple principle of respect to other members of this Community, should be disc...