We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Topics - IQ_imbalance

Pages: 1 ... 3 4 5 6 7 8 9 10 [11]
Equipment / Sky loop...height vs diameter
« on: August 02, 2014, 1435 UTC »
This may have already been discussed but for some reason tapatalk doesn't want to let me search through posts....so here goes.

For a sky loop antenna, which variable has the largest effect on reception...height above ground or diameter?  It's a practical question since I could put a loop around the top story of my house (guessing a 28 m loop....maybe 60m if I shoot a line to the backyard trees) without much effort, but while a loop around the entire house would be twice the diameter (up to 120m perhaps, again including a treetop run) the loop would only be ~3 meters above the ground on the front .  The house is on the side of a hill so the front is much closer to the ground than the back.

I -might- be able to rig up a valley span longwire, but it would be in the bottom of the valley (running SW to NE) and probably only 10m or so high so it might not be worth the trouble.  That's also assuming I can get enough tension on it, otherwise I might close line folks passing by in their kayaks :)

Shortwave Broadcast / Radio Havana 6000MHz AM 0339 UTC
« on: August 01, 2014, 0341 UTC »
Just the news (including updates on the pineapple crop) and a bit of music.  Nothing terribly exciting but a good strong signal.

FM DX Loggings / Skip OK to MD 1400 UTC 31 July 2014
« on: July 31, 2014, 1717 UTC »
Picked up a very strong dx on 88.5 MHz from KZTH in Piedmont, OK.  Was strong enough to drown out WAMU on 88.5 MHz.

My QTH was Frederick, MD and rx was on a stock car radio(!)

I've spent some time searching, and while i've found several online db containing aircraft info (particularly aircraft type) I am having trouble finding data that can be downloaded and used to decode mode-s on a local machine.  I'm particularly interested in milair, since the CAP has been flying overhead since yesterday AM.  I did manage to find a file listing aircraft type by tail number, and if there is a file somewhere with the ICAO codes and tail numbers I could always merge the info.

Oh, I posted this in the SDR section because I'm using my R820T :)


Some trials and tribulations.  Bought a NooElec RTL-SDR off Amazon, and configured an old Powerbook G4 with Ubuntu 12.04 to run it.  Installed gnuradio, rtl-sdr, etc from source  (miraculously) without issues.  Was able to build some simple radio/fft devices with gnuradio-companion but everytime I tried to demodulate a signal I received volk memory errors.  Rtl_test shows the dongle is working, but rtl_fm wouldn't demodulate wbfm signals to anything intelligible (static was all i could make out!). 

At this point I was fearing I had a deaf RTL-SDR, and decided to at least try it on a different hardware/software combo to be sure.  Installed Gqrx on an intel Mac running 10.7...and BINGO.  It was pulling in WBFM (and NFM) just fine. 

So...some ups and downs.  Haven't tried using the dongle with Gnuradio on the intel mac yet but that's in the near future.  Not sure what to do about my Ubuntu PPC system yet....I might try downloading individual components and recompiling.

North American Shortwave Pirate / UNID 6925USB 0202Z 20130311
« on: March 11, 2013, 0205 UTC »
Hearing the blues over a WebSDR physically located in the Netherlands. 

General Radio Discussion / Tones on 14105 LSB 1813Z
« on: March 03, 2013, 1813 UTC »
Was trying to find some packet HF to decode, and instead of hearing (or seeing) two distinct tones I keep getting a rapid series of rapid tones spanning about 1300 Hz.  The sequence starts with a second or so of a 500 Hz tone, then the rapid series of quick tones.

SDR - Software Defined Radio / Raspberry Pi, antennas, and SDR
« on: February 14, 2013, 0231 UTC »
So now that you can pretty much have a complete computer for $35 or so, and add on a SDR for another $15....thoughts on how this might be fun?  Since you could have a $50 receiver right at your antenna, would it be easier to build arrays since you wouldn't have to worry about losses in the feed (just about running the ethernet cables between the boxes...)?

Earlier today I tried to log in with tapatalk for iOS and received an error that access from tapatalk was restricted or that the forum plugin wasn't functioning.  Has anyone else had a problem with tapatalk lately?

North American Shortwave Pirate / SSTV or FAX 6925u 0146Z
« on: July 07, 2008, 0152 UTC »
Sounds like SSTV(?) or FAX.  Fades in and out.

If it _is_ SSTV, is there anyway to tell what mode? 

Pages: 1 ... 3 4 5 6 7 8 9 10 [11]
HFUnderground Mug
HFUnderground Mug
by MitchellTimeDesigns