Search found 34 matches

by AD5NL
Thu Feb 21, 2019 7:47 pm
Forum: Antennas
Topic: Best antenna for 1mhz-50 and 1khz - 800khz
Replies: 5
Views: 14897

Re: Best antenna for 1mhz-50 and 1khz - 800khz

A few notes/thoughts: 1 MHz to 50 MHz is a very large range and having a single antenna handle all of that can be a bit tricky, but there are many commercially-available ham HF antennas that can do this. A few options: * An active whip (you can find these on eBay for about $20). * A doublet fed with...
by AD5NL
Sat Apr 22, 2017 10:57 pm
Forum: RTL-SDR Discussion
Topic: Which upconverter to buy???
Replies: 6
Views: 4625

Re: Which upconverter to buy???

Just to be sure -- have you tried Q-branch direct sampling in SDRSharp?

I find that the v3 RTL-SDR.com dongle does a fine job of HF reception on its own, although I'd agree that if you were doing real "work" (ham contesting, receiving WEFAX professionally, etc) an upconverter would be a good idea.
by AD5NL
Sat Apr 01, 2017 5:01 am
Forum: User Projects
Topic: Using satellite doppler effect to determine position
Replies: 4
Views: 5123

Using satellite doppler effect to determine position

Hi everyone, I was watching an old episode of James Burke's "Connections" documentary, and in one he uses an old satellite navigation system that relies on measuring the doppler effect of a passing satellite, to calculate the position of the user on earth. The idea being, that the doppler shift freq...
by AD5NL
Mon Jan 16, 2017 10:23 pm
Forum: Antennas
Topic: transition from SDR to a outside discone
Replies: 4
Views: 8178

Re: transition from SDR to a outside discone

Radio Shack has the same part but it'll cost you $20.

Unless you have an emergency ("my kid's science project is due tomorrow!") then I would highly suggest buying online, whether it be "from China" or through Amazon.
by AD5NL
Mon Jan 16, 2017 10:16 pm
Forum: Other SDR Devices
Topic: The LimeSDR Hype Train Is (Finally) Leaving The Station
Replies: 0
Views: 3348

The LimeSDR Hype Train Is (Finally) Leaving The Station

An update was posted today on CrowdSupply indicating the first 500 LimeSDRs will be shipping in the next 24 hours.

https://www.crowdsupply.com/lime-micro/ ... n-24-hours
by AD5NL
Fri Jan 13, 2017 8:18 pm
Forum: Antennas
Topic: Best Antenna Combinations?
Replies: 2
Views: 6998

Re: Best Antenna Combinations?

A few things to keep in mind: * Every antenna is a compromise. For HF: * Unless directionality is preferred, it is rather difficult to outperform a half-wave dipole that is properly built for the desired band. * A dipole is really cheap to build at home. Keep in mind also that dipoles usually work f...
by AD5NL
Fri Jan 13, 2017 7:30 pm
Forum: Other SDR Devices
Topic: Can a Uniden BC785D scanner be used as a tuner for rtl-sdr?
Replies: 2
Views: 3847

Re: Can a Uniden BC785D scanner be used as a tuner for rtl-s

Probably, but it will require carefully gathering information about your device, carefully soldering in some tap wires, and it will definitely void your warranty. Here is what you would do: 1. Get the User Manual, Service Manual, and Schematic for the radio. You might also want to get the FCC Databa...
by AD5NL
Wed Jan 11, 2017 9:39 pm
Forum: RTL-SDR Discussion
Topic: I need answer about this...
Replies: 11
Views: 7271

Re: I need answer about this...

One caveat -- if you are *extremely nearby* then the guy might see you / hear you / detect the weak signal from your radio's local oscillator.
by AD5NL
Wed Jan 11, 2017 9:38 pm
Forum: RTL-SDR Discussion
Topic: I need answer about this...
Replies: 11
Views: 7271

Re: I need answer about this...

Well, obviously if you listen to your radio then you'll suck up all the RF and nobody else can hear him. (just kidding!) Pretty much the only way that a person would know that their signal has been intercepted is if you told them. That is why ham radio operators invented QSL cards (a snailmail postc...
by AD5NL
Mon Jan 09, 2017 11:28 pm
Forum: RTL-SDR Discussion
Topic: How do I "see" the digital data being transmitted?
Replies: 8
Views: 5382

Re: How do I "see" the digital data being transmitted?

What mode is being transmitted?