Search found 662 matches
- Sun Oct 07, 2018 8:59 pm
- Forum: General
- Topic: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
- Replies: 13
- Views: 35478
Re: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
A complete 3 way receiver feed system for one antenna with controlled attenuation and SDRplay switching is shown below. A 400 Ohm antenna is perfectly matched by a parallel connection of three attenuators, each with an input impedance of 1200 Ohm. Loss for the parallel connection amounts to 10 dB. T...
- Sat Oct 06, 2018 4:00 pm
- Forum: General
- Topic: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
- Replies: 13
- Views: 35478
Re: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
It is possible to switch the same antenna between two, or even all three antenna inputs (with a third transformer) using the RDSPlay switch only. This setup allows very quick switching for comparing different noise/propagation conditions. Of course this is only possible when attenuation is necessary...
- Fri Oct 05, 2018 5:46 pm
- Forum: General
- Topic: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
- Replies: 13
- Views: 35478
Re: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
It is also possible to recover the correct reading of the noise floor, of the display and of the "S" meter by altering the DISPLAY CALIBRATION as shown in the enclosed screen. If, for instance, you install a 20 dB attenuator, the receiver's front end will still receive 20 dB less and be 20 dB farthe...
- Fri Oct 05, 2018 2:53 pm
- Forum: General
- Topic: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
- Replies: 13
- Views: 35478
Re: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
Here below a modified attenuator table based on multiples of 6 dB so that it will be easy to correct the "S" units indication by the RSP receiver. For instance, if you have inserted 24 dB of front end attenuation and your meter reads 2 "S" units, you are receiving a signal with "S" = 2+4 = 6 signal ...
- Fri Oct 05, 2018 1:46 pm
- Forum: General
- Topic: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
- Replies: 24
- Views: 70969
Re: ASSESSING THE PERFORMANCE OF THE RSP RECEIVER SYSTEM IN HF
6. APPENDIX – DEMONSTRATION OF THE ANTENNA CORRECTION PROCEDURE We rewrite here again the expression developed in Part 3: Pn = Fa + B – 204 [dBm] ( 8 ) Solving for Fa, effective antenna Noise Figure, we have: Fa = Pn + 204 – 10*LOG10(b) [dB] ( 8bis ) As already stated, the Noise Power Pn delivered ...
- Fri Oct 05, 2018 9:53 am
- Forum: General
- Topic: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
- Replies: 13
- Views: 35478
Re: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
In summary, to find the required attenuation: 1) Connect termination to input and find Terminated Receiver Noise Floor -Rnf 2) Find Receiver minimum detectable signal Rmds = -Rnf + 6 3) Connect antenna and find -Anf 4) Find Antenna minimum detectable noise floor Amds = -Anf + 6 5) Find attenuator va...
- Thu Oct 04, 2018 6:31 pm
- Forum: General
- Topic: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
- Replies: 13
- Views: 35478
Re: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
Antenna is L=135 m Beverage, H = 6m
Uploaded below screens of 20 dB attenuated / non attenuated RSPduo reception on the 80 m band.
Uploaded below screens of 20 dB attenuated / non attenuated RSPduo reception on the 80 m band.
- Thu Oct 04, 2018 6:30 pm
- Forum: General
- Topic: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
- Replies: 13
- Views: 35478
Re: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
Antenna is L=135 m Beverage, H = 6m
Uploaded below screens of 20 dB attenuated / non attenuated RSPduo reception on the 40 m band.
Uploaded below screens of 20 dB attenuated / non attenuated RSPduo reception on the 40 m band.
- Thu Oct 04, 2018 6:29 pm
- Forum: General
- Topic: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
- Replies: 13
- Views: 35478
Re: OPTIMIZING RSP RECEIVER OPERATION WITH ANTENNA NOISE
Antenna is L=135 m Beverage, H = 6m
Uploaded below screens of 20 dB attenuated / non attenuated RSPduo reception on the 20 m band.
Uploaded below screens of 20 dB attenuated / non attenuated RSPduo reception on the 20 m band.
- Thu Oct 04, 2018 1:14 pm
- Forum: General
- Topic: RSP RECEIVER LOW NOISE HF OPERATION WITH LONG WIRE ANTENNAS
- Replies: 30
- Views: 90302
Re: RSP RECEIVER LOW NOISE HF OPERATION WITH LONG WIRE ANTENNAS
FINAL ASSESSMENT OF HIGH PASS FILTER ACTION AND POSSIBLE NOISE ADVANTAGE After a series of measurements it has been determined that the biggest part of the noise advantage shown by the highpass filter in HF was provided by the significant attenuation (6-8 db) of the filter itself, depending on oper...