Search found 120 matches

by sdrom33
Wed Jul 17, 2019 10:09 pm
Forum: SDR Antennas
Topic: A FOOLPROOF ANTENNA SWITCH
Replies: 35
Views: 7597

Re: A FOOLPROOF ANTENNA SWITCH

Perhaps I did not explain myself well enough. IF YOU CAREFULLY READ THE CITED REFERENCES, Panasonic, for instance, NO RELAY CONTACT IS GUARANTEED TO WORK WITHOUT CURRENT FOR AN UNDEFINED PERIOD OF TIME, UNLESS IT IS A MERCURY RELAY. AND FOR SOME SOURCES NOT EVEN THOSE. EVEN THE BEST CONTACT MATERIAL...
by sdrom33
Wed Jul 17, 2019 6:53 pm
Forum: SDR Antennas
Topic: A FOOLPROOF ANTENNA SWITCH
Replies: 35
Views: 7597

Re: A FOOLPROOF ANTENNA SWITCH

HI Mike, Your experience is very informative and clearly shows the risks and pitfalls in circuit design. Reliability analysis, based on MIL specs, was done in the company I was working for several years and the most difficult process was that of finding an optimum balance between component count and...
by sdrom33
Tue Jul 16, 2019 6:42 pm
Forum: SDR Antennas
Topic: A FOOLPROOF ANTENNA SWITCH
Replies: 35
Views: 7597

Re: A FOOLPROOF ANTENNA SWITCH

Hi glovisol, I agree with Mike that two series capacitors are needed to avoid the danger of shorting the bias voltage. I also note that with the circuit as is now the antenna common lead is shorted to the 12 V supply common lead and this could bring noise in. It would be advisable to put a choke in ...
by sdrom33
Mon Jul 15, 2019 7:41 pm
Forum: SDR Antennas
Topic: A FOOLPROOF ANTENNA SWITCH
Replies: 35
Views: 7597

Re: A FOOLPROOF ANTENNA SWITCH

Hi Tech_Support, I am glad you have eliminated posts with controversial arguments that do nothing but creating confusion and ill feelings among forum members. With sincere appreciation,

Thomas
by sdrom33
Sun Jul 14, 2019 9:30 pm
Forum: General
Topic: Decoding Meteor Satellites with RSP Receivers and SDR Sharp via RTL_TCP server
Replies: 5
Views: 453

Re: Decoding Meteor Satellites with RSP Receivers and SDR Sharp via RTL_TCP server

Thanks to Mike and to RSP2user for the information and also kudos for very impressive images!
by sdrom33
Sun Jul 14, 2019 9:25 pm
Forum: Spectrum Analysis
Topic: Evaluating RF filters?
Replies: 19
Views: 661

Re: Evaluating RF filters?

Mike, it seems to me that your filter is low pass filter, e.g. suppresses MW & higher band to let you get the LW band. I am under the impression, .maybe I am wrong, that Franko wants a high pass filter, to suppress MW in order to listen to HF from 1.9 MHz & higher, as shown by glovisol.
by sdrom33
Sat Jul 13, 2019 6:00 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 66
Views: 3468

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

Hi Phil & Gianfranco, it seems to me that this thread, that had to be closed, because it had become "toxic" according to some guys, is by contrast showing a lot of useful information on small antennas. This is a lesson to us all that a good discussion on technical problems and data is ...
by sdrom33
Wed Jul 10, 2019 10:56 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 66
Views: 3468

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

Phil,

Thanks a lot for your help & guidance. I am studying the references, got a lot to learn in practical antennaship & will get back to you when stronger on my legs. Seems glovisol is having a ball with your concepts!
by sdrom33
Wed Jul 10, 2019 10:52 am
Forum: General
Topic: hdsdr?
Replies: 2
Views: 264

Re: hdsdr?

LNA gain depends on noise level of your antenna. Get a signal and then adjust for best S/N.
For mouse you should go to the mouse controller & change settings.

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