Search found 658 matches

by glovisol
Wed Jul 24, 2019 5:44 pm
Forum: SDR Antennas
Topic: Receive Antenna & Impedance "Matching"
Replies: 114
Views: 16286

Re: Receive Antenna & Impedance "Matching"

CLARIFICATION ON SENSITIVITY PERFORMANCE COMPARISON RSP-1A VS. RSPduo & FOCUS ON NEGATIVE S/N 8. SDR Noise Figure performance @ 7-8 MHz Finally we can look at the 40 m Band, because on this frequency vk7jj published most of his results for WSPR reception. The SDRplay published N.F. data here is as ...
by glovisol
Wed Jul 24, 2019 4:39 pm
Forum: SDR Antennas
Topic: Receive Antenna & Impedance "Matching"
Replies: 114
Views: 16286

Re: Receive Antenna & Impedance "Matching"

CLARIFICATION ON SENSITIVITY PERFORMANCE COMPARISON RSP-1A VS. RSPduo & FOCUS ON NEGATIVE S/N 7. SDR Noise Figure performance @ 80 KHz A legitimate objection that could be opposed to the data published and the quantities computed in the previous post is that the SDR Noise Figures taken from the pub...
by glovisol
Wed Jul 24, 2019 12:38 pm
Forum: General
Topic: RSP-2 HiZ Input Question: 1:9 Balun and Grounding ?
Replies: 7
Views: 895

Re: RSP-2 HiZ Input Question: 1:9 Balun and Grounding ?

Dear Robert 11, if you read this thread: https://www.sdrplay.com/community/viewtopic.php?f=8&t=4493 and this: https://www.sdrplay.com/community/viewtopic.php?f=5&t=3352&hilit=sensityvity+measurement Of course you will need a lot of patience, as they are long threads, but then a clear picture will un...
by glovisol
Wed Jul 24, 2019 11:15 am
Forum: SDR Antennas
Topic: Receive Antenna & Impedance "Matching"
Replies: 114
Views: 16286

Re: Receive Antenna & Impedance "Matching"

CLARIFICATION ON SENSITIVITY PERFORMANCE COMPARISON RSP-1A VS. RSPduo & FOCUS ON NEGATIVE S/N I believe the previous two posts have introduced confusion on several important questions and with this post I wish to clarify some ESSENTIAL concepts. 1. RSP-1A and RSPduo Sensitivity & Noise Figure speci...
by glovisol
Wed Jul 24, 2019 5:50 am
Forum: General
Topic: BUILDING SELECTIVITY PROTECTION INTO THE RSP FRONT END IN LF/HF
Replies: 19
Views: 3054

Re: BUILDING SELECTIVITY PROTECTION INTO THE RSP FRONT END IN LF/HF

2.3. A DIGRESSION - NARROW BAND PRE-SELECTORS COMPUTER SIMULATION Uploaded below Figures 4 & 5 showing simulated performance @ 4 MHz. Figure 4 (under top title) shows the following parameters: CF- Center Frequency: 4 MHz Qu - Unloaded Q: 350 QL- Loaded Q: 80 IL - Insertion loss: 2.3 db L - Coil ind...
by glovisol
Tue Jul 23, 2019 7:05 pm
Forum: General
Topic: BUILDING SELECTIVITY PROTECTION INTO THE RSP FRONT END IN LF/HF
Replies: 19
Views: 3054

Re: BUILDING SELECTIVITY PROTECTION INTO THE RSP FRONT END IN LF/HF

2.3. A DIGRESSION - NARROW BAND PRE-SELECTORS COMPUTER SIMULATION In general a narrow band pre-selector consists of a tuneable single tuned bandpass L/C circuit placed between antenna output and receiver input. The inductor is wound on a Powdered Iron toroid core and the capacitor is an air variabl...
by glovisol
Tue Jul 23, 2019 5:06 pm
Forum: SDR Antennas
Topic: DCF 77 77.5KHZ
Replies: 17
Views: 1962

Re: DCF 77 77.5KHZ

Hi VK3MHz, Perhaps the thread below on my adventures with a 160 m long Beverage antenna could be of help. https://www.sdrplay.com/community/viewtopic.php?f=8&t=4493 What is notable in this thread is that I proved that to obtain remarkable low noise operation you must forget about stake ground as the...
by glovisol
Tue Jul 23, 2019 10:27 am
Forum: General
Topic: BUILDING SELECTIVITY PROTECTION INTO THE RSP FRONT END IN LF/HF
Replies: 19
Views: 3054

Re: BUILDING SELECTIVITY PROTECTION INTO THE RSP FRONT END IN LF/HF

It has come to my mind that with my previous post I have perhaps given the impression that the pre-selectors introduced by mike0agner are not technically effective and therfore not useful. If this is the case I sincerely apologize . On the contrary, my only criticism was the lack of published specs,...
by glovisol
Tue Jul 23, 2019 6:42 am
Forum: General
Topic: BUILDING SELECTIVITY PROTECTION INTO THE RSP FRONT END IN LF/HF
Replies: 19
Views: 3054

Re: BUILDING SELECTIVITY PROTECTION INTO THE RSP FRONT END IN LF/HF

Thank you for directing our attention to these two commercially available pre-selectors. Both of them, in the frequency ranges they cover, will protect the RSP front end by reducing the bandwidth seen by the front and therefore the chance of overload and spurious. My only regret is that these units,...
by glovisol
Mon Jul 22, 2019 4:57 pm
Forum: SDR Antennas
Topic: A FOOLPROOF ANTENNA SWITCH
Replies: 32
Views: 9497

Re: A FOOLPROOF ANTENNA SWITCH

Now that luckily a lot of confusing information on this thread has been removed, as a service to those who did not follow the cancelled discussion and may be worried by the bits of controversy left over, but still need to build and use the Antenna Swich in question, I can confirm that this switch wi...