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by glovisol
Sun Jul 14, 2019 7:27 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 66
Views: 3128

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

Hi Thomas. I agree with you, even if we should understand that words perhaps written in anger are not really meant and should be quickly forgotten. But you are right in observing that this thread, born under such unhappy auspices, has turned to the better. Now, thanks to Phil's suggestions and help,...
by glovisol
Sun Jul 14, 2019 5:09 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 66
Views: 3128

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

Hi Phil, You have really convinced me and surely I am going to put up a big loop antenna once I get home in August. Here at the sea side I did not have any antenna at all and fortunately followed your suggestion and started experimenting with small loops. The results are incredible, because I see pl...
by glovisol
Sun Jul 14, 2019 9:53 am
Forum: Spectrum Analysis
Topic: Evaluating RF filters?
Replies: 19
Views: 548

Re: Evaluating RF filters?

Spectrum 0-1900 KHz with filter.jpg
Spectrum 0-1900 KHz with filter.jpg (183.38 KiB) Viewed 127 times
Franko, this is what you need to get rid of MW interference, it is effective and easy & inexpensive to build, just look at the thread.

viewtopic.php?f=5&t=3973#p12847

glovisol
by glovisol
Sat Jul 13, 2019 6:47 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 66
Views: 3128

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

And this evening at 18:45 GMT with good propagation......
by glovisol
Sat Jul 13, 2019 6:42 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 66
Views: 3128

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

More reception examples with non-optimized original cross pallet loop antenna. The peculiar thing, that comes to attention at once, is the low level of backgrund noise: under these conditions, signals at levels of -115 to -120 dBm are easily copied witout problems, even if the S meter shows S1 to S3.
by glovisol
Sat Jul 13, 2019 5:49 pm
Forum: Spectrum Analysis
Topic: Evaluating RF filters?
Replies: 19
Views: 548

Re: Evaluating RF filters?

More in-forum references for filter measuremet & evaluation with RSP Spectrum Analyser software: https://www.sdrplay.com/community/viewtopic.php?f=5&t=3943&p=14894&hilit=filter#p14894 https://www.sdrplay.com/community/viewtopic.php?f=5&t=4364&p=14875&hilit=filter#p14875 h...
by glovisol
Sat Jul 13, 2019 4:05 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 66
Views: 3128

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

METHOD FOR PASSIVE BROADBAND MATCHING OF A SMALL LOOP ANTENNAS IN HF The method outlined in the previous post is indeed theoretically possible, using data for polynomial filters with unequal terminations. In Reference 1 below, tables of lowpass element values are presented for filters accommodating...
by glovisol
Fri Jul 12, 2019 1:37 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 66
Views: 3128

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

Hi Phil, I slept on it and was even more convinced this morning, so here is my idea, which is probably the re-invention of the wheel, or perhaps there will be 999 reasons why it will not work. I only have to wait until I get back home in August and test it. METHOD FOR PASSIVE BROADBAND MATCHING OF A...
by glovisol
Thu Jul 11, 2019 3:18 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 66
Views: 3128

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

Phil, It is not coax at all, it is a short section of electrical twin wire, like zip cord. I wish I had coax here, I have nothing!! Thank you for your calcs. The picture I see is quite simple: Antenna loop calc.png We DO NOT wish to tune the inductive reactance, because we wish to have a wideband an...
by glovisol
Thu Jul 11, 2019 5:57 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 66
Views: 3128

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

Hi Phil & Paul, 1) Very many thanks for the modeling @ 7 Mhz, which is mid-band, as the antenna works fine down to 3.6 and up (best at 14 MHz). The transformer at present is 450 to 1000 Ohm. From your data, at last @ 3.6 MHz, it should be rather 200 to 1000 Ohm, but Z data up to 14 MHz should be...

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