Search found 51 matches

by Aussie Susan
Wed Mar 14, 2018 1:41 am
Forum: Troubleshooting Help
Topic: poor quality noaa images
Replies: 2
Views: 3711

Re: poor quality noaa images

Check out http://www.wxtoimg.com/support/wxfaq.html and look at the "Image Slant" section.
Susan
by Aussie Susan
Wed Feb 28, 2018 2:05 am
Forum: Antennas
Topic: Where do the antenna actually begin?
Replies: 8
Views: 9782

Re: Where do the antenna actually begin?

Another answer could be that neither of these are where the antenna begins because you are using shielded wire and to it is only carrying the signal to where the antenna really is! And yes I know that the cable does have an effect. However at 1.06GHz, the wavelength is about 270mm in free space and ...
by Aussie Susan
Tue Feb 27, 2018 1:14 am
Forum: Antennas
Topic: Where do the antenna actually begin?
Replies: 8
Views: 9782

Re: Where do the antenna actually begin?

Depending on the frequency, I would say that it probably makes no difference. Given the frequency you can work out the wavelength (I'd multiply it by something like 0.8 as this is wire and not free space). If the wavelength is more than a cm or two then the result will be the same no matter where yo...
by Aussie Susan
Mon Feb 26, 2018 2:44 am
Forum: Antennas
Topic: Is it normal for an antenna not have lowest swr in its advertised band?
Replies: 7
Views: 8353

Re: Is it normal for an antenna not have lowest swr in its advertised band?

The scale you are using is quite large. I guess the real question is, does it have the SWR that the manufacturer stated at the frequency of interest? If it does then you have what you bought. If not then you might have a case for misleading advertising and getting your money back (certainly here in ...
by Aussie Susan
Mon Jan 29, 2018 2:56 am
Forum: RTL-SDR Discussion
Topic: unknow radio stations on 27 mc
Replies: 4
Views: 5235

Re: unknow radio stations on 27 mc

Isn't that Citizen Band?
Would not explain the long distance though...
Susan
by Aussie Susan
Thu Jan 25, 2018 5:27 am
Forum: Off-Topic
Topic: NSA Tracking of powered down cellphones and other wireless devices
Replies: 7
Views: 24122

Re: NSA Tracking of powered down cellphones and other wireless devices

What you are describing (bounding a strong enough signal off a 'dead' device) is basically what I was mentioning above about the RFID chips. The trick is to know the appropriate frequency before hand. For the RFID chips that is easy as they are designed to respond to a given frequency. For other dev...
by Aussie Susan
Mon Jan 22, 2018 1:48 am
Forum: Off-Topic
Topic: NSA Tracking of powered down cellphones and other wireless devices
Replies: 7
Views: 24122

Re: NSA Tracking of powered down cellphones and other wireless devices

Also check out how RFID systems work where the device is "powered" by the reader. Also there are a number of new devices coming on to the market with 'wireless charging'. I know this is not what you are talking about as both of those examples have the 'other end' device designed to respond to the re...
by Aussie Susan
Wed Jan 10, 2018 1:46 am
Forum: Antennas
Topic: HF-Antenna made from wire -Ideas?
Replies: 4
Views: 7445

Re: HF-Antenna made from wire -Ideas?

Amateur radio operators have that problem all the time (especially those that live in apartments or have various restrictions on what they can erect) with the added 'bonus' or wanting to transmit as well. Try a Google search for 'stealth hf antenna' or 'limited space antenna' and you might get some ...
by Aussie Susan
Thu Dec 28, 2017 2:39 am
Forum: User Projects
Topic: Demodulate FSK
Replies: 6
Views: 23295

Re: Demodulate FSK

(A bit off topic i know but...) Is there a similar reference for mPSK (especially QPSK) as is used for LRPT? I've been looking for such a thing for a while as I've successfully FM demodulated the NOAA POESs and I'd like to try to METEOR M2 satellite signal as well. Thanks for the above reference - i...
by Aussie Susan
Fri Dec 15, 2017 1:10 am
Forum: RTL-SDR Discussion
Topic: NOAA Satellite Reception [HELP]
Replies: 4
Views: 5001

Re: NOAA Satellite Reception [HELP]

They look like some of my images (I'm based in Melbourne so I also have a similar coastline showing up). I have a QFH antenna with an LNA and I can also get some quite decent images as well. I use an SDRPlay RSPII rather than the RTL-SDR but that is possibly not important here. What you are seeing i...