Search found 662 matches

by glovisol
Mon Jul 15, 2019 4:09 pm
Forum: Spectrum Analysis
Topic: Evaluating RF filters?
Replies: 19
Views: 9141

Re: Evaluating RF filters?

This filter is simpler & easier to make, it would be good as a first experimental unit. It is a Chebyshev N=5, r=0.5 dB, Zin=Zout=500 Ohm as the previous Cauer filter.
Chebyshev MW band elimination notch filter.jpg
Chebyshev MW band elimination notch filter.jpg (57.26 KiB) Viewed 5118 times
by glovisol
Mon Jul 15, 2019 3:13 pm
Forum: Spectrum Analysis
Topic: Evaluating RF filters?
Replies: 19
Views: 9141

Re: Evaluating RF filters?

ERRATA CORRIGE: in the schematic I omitted to put the value of the capacitor in series with the 336 uH inductor: value is 215 pf. Sorry for that!
by glovisol
Mon Jul 15, 2019 2:41 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 25217

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

Hi Phil, it is exactly that. You pushed me and I am now going full blast. Yesterday I increased the side of the square from 88 cm to 1.29 cm. The practical footprint space actually taken by the antenna is the same, but the capture surface has more than doubled, from 0.77 sq. metres to 1.66 sq. metre...
by glovisol
Mon Jul 15, 2019 1:53 pm
Forum: SDR Antennas
Topic: A FOOLPROOF ANTENNA SWITCH
Replies: 30
Views: 21883

Re: A FOOLPROOF ANTENNA SWITCH

Thanks again, Tech_Support, for defending our Forum,

Gianfranco
by glovisol
Mon Jul 15, 2019 6:52 am
Forum: SDR Antennas
Topic: A FOOLPROOF ANTENNA SWITCH
Replies: 30
Views: 21883

Re: A FOOLPROOF ANTENNA SWITCH

After reading the reference material provide by Ian1951, IMO the title of this post should be changed to 'A Fool's Antenna Switch'. And yikes, hanging this switch from the SMA connector of the radio's plastic case sends chills up my spine. Mike, I do not know why one should hang the switch directly...
by glovisol
Mon Jul 15, 2019 6:40 am
Forum: Spectrum Analysis
Topic: Evaluating RF filters?
Replies: 19
Views: 9141

Re: Evaluating RF filters?

Hi Franko, Having long ago prepared Excel spreadsheets for quick calculation of any type filters, once you plug in the available filter prototype tabulated data, I could quickly check your specification and the result is shown below. This filter is complex, but with easily realizable components, pro...
by glovisol
Sun Jul 14, 2019 7:27 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 25217

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: 57
Views: 25217

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: 9141

Re: Evaluating RF filters?

Spectrum 0-1900 KHz with filter.jpg
Spectrum 0-1900 KHz with filter.jpg (183.38 KiB) Viewed 3669 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.

https://www.sdrplay.com/community/viewt ... 973#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: 57
Views: 25217

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

And this evening at 18:45 GMT with good propagation......