Hello LF'ers Is anyone able and willing to advise on my band pass RX filter design please? I have made a band pass filter for 137kHz reception and checked it with my SDR in real time. It is shifted a
Hi Chris, Add some C across the other Cs. If you have 2 nF currently and the frequency is at 150 kHz, then try to add 200 pF. Just try it out, forget the simulations. 73, Stefan Am 23.08.2018 13:08,
Ehm sorry, rather add 400 pF. I just calculated (150/137)^2 ~ 1.2, i.e. you need 1.2 times more C, or 2.4 nF. 73, Stefan Am 23.08.2018 13:34, schrieb DK7FC: Hi Chris, Add some C across the other Cs.
The caps are likely to be close to their proper value ], which leaves the values of the inductors. You have E12 preferred values so guess you're using ready made L components. They may be specified a
Hello DK7FC Stefan, No worries, I will try this tonight, thank you. My method of testing is a wide band commercial noise source and two series wide band amps to up the level to something useable by m
Hello Andy, Thanks for checking, glad we concur! I am an expert at frigging about, sounds OK to me, I'll post my results in due course, all the best! -- Best regards, Chris mailto:[email protected]
Hi Chris, Am 23.08.2018 14:38, schrieb Chris Wilson: My method of testing is a wide band commercial noise source and two series wide band amps to up the level to something useable by my SDR, then loo
Hello DK7FC Stefan, I am seeing better SNR and more WSPR receptions in general with the BPF in place, especially at night when the huge BBC broadcast signal on 198kHz that's not THAT far from me beco
Hi Chris, maybe you are better off with a 198kHz notch filter? 73, Rik ON7YD - OR7T Hello DK7FC Stefan, I am seeing better SNR and more WSPR receptions in general with the BPF in place, especially at
Hi Chris, I sent an earlier reply which seems to have gone into the bit bucket somewhere, possibly to due to server settings in my mail client which I've just now changed back to what was working pre
Chris, I think it's time to show us a photo of your BPF construction :-) Don't hesitate to leave all the stuff on the workbench as it is ;-) 73, Stefan Am 23.08.2018 20:26, schrieb N1BUG: Hi Chris, I
Hello Paul, Thanks for the reply. I added a 470pF cheap disc ceramic across each of the 2000pF polystyrene caps, and indeed the filter moved lower, to pretty much the optimum spot (thank you Stefan).
Hello DK7FC Stefan, I have gone to bed as I have an early start tomorrow, but I will take a photo tomorrow and you can have a good laugh, at the filter and the bench ;) Thanks for your help. -- Best
On Thu, 23 Aug 2018 at 12:08, Chris Wilson <[email protected]> wrote: Hello LF'ers Is anyone able and willing to advise on my band pass RX filter design please? I have made a band pass filter for
Am 23.08.2018 22:04, schrieb Chris Wilson: Hi Chris, I added a 470pF cheap disc ceramic across each of the 2000pF polystyrene caps, and indeed the filter moved lower, to pretty much the optimum spot
