Spectrograms on webflash.ess.washington.edu
With which device are the spectrogrammes shown on http://webflash.ess.washington.edu/ made? With a standard PC with soundcard? Or with a much better device in order to avoid phantom signals? Re: Spectrograms on webflash.ess.washington.edu
The questions seems to be from special interest, because the diagram of Puerto Rico http://webflash.ess.washington.edu/bobholz/toga/puertorico/vlf.png shows a strong unidentified signal around 12 kHz. Where does it come from?
Where are the receivers which deliver the spectrogrammes on http://webflash.ess.washington.edu/ exactly placed? On sites without much man-made noise?
Are these spectrograms in general more reliable than those made by standard PCs at the shown sites?
Posted by John Davis on May 04, 2006 at 15:06:28.
In reply to Spectrograms on webflash.ess.washington.edu posted by Harald on May 04, 2006
::Are these spectrograms in general more reliable than those made by standard PCs at the shown sites?::
I am not sure in what sense you mean "more reliable," but it would be accurate to say these spectrograms are made under significantly more standardized conditions than most private experimenters employ.
The observing stations use an antenna constructed and positioned according to the University of Washington's specifications. They allow the use of any networkable computer, provided that it can drive a soundcard based on a sigma-delta A/D converter, rather than a conventional PCM A/D converter, at 48kilosamples/second. The University furnishes the software (and hardware, where export laws permit) and they manage the computer across a mandatory high speed Internet connection with fixed IP address. In addition, precise time synchronization must be provided to the computer by a GPS receiver.
More technical details can be found at the "Do It Yourself manual" link on their home page. Beyond that, you would need to contact Professor Holzworth directly.
I think it is safe to say that the traces between 11 and 12 kHz on the Puerto Rico spectrogram are not genuine signals, but are probably aliases (spurious products produced during the A/D conversion, due to inadequate low pass filtering) of the very powerful LF signals from the US Navy station on the island. They are not detrimental to the intended purpose of the receiving site, which is to determine time of arrival of broadband lightning transients.
John
DI2BO - 2nd German License for Experimental 440 kHz operation
Posted by Geri, DK8KW on May 06, 2006 at 09:49:00.
Hello YLs and OMs,
since January 2005 tests are conducted to study the special propagation conditions on medium wave. Walter, DJ2LF in Dormitz near Nuernberg operates the experimental station DI2AG on 440 kHz. Supplementary to these test transmissions the German radio authorities issues a second license for an experimental radio station which is oeprated by Holger ('Geri'), DK8KW in Peine near Hannover (JO52BH). The callsign of this station is DI2BO.
The permitted operating conditions of DI2BO are the same as for DI2AG. Test transmissions will be conducted on 440 kHz plus/minus 100 Hz with a maximum radiated power of 9 Watt ERP. Both beacon transmissions will be coordinated in a way so that they can be observed simultaneously to study the porpagation from both locations at the same time. Also two-way contacts between both experimental stations are planned. Further Information will be published on the website http://www.qru.de/di2bo.html.
DI2BO is using a marine radio transmitter DEBEG 7121 with about 130 Watt outpt power and an 18 meter high umbrella antenna with 5 top load radials. Theoretically this configuration should result in a maximum effective radiated power of around 5 Watt ERP.
Best 73
Geri, DK8KW / DI2BO (W1KW)
Newbie
Posted by Jerry on May 08, 2006 at 21:34:28.
I'm near Rapid City, South Dakota. Are there any beacons of Lowfers near enough for me that should be easy to hear?? The reason I ask is I recently got a Radio Shack DX-160 reciever and I have yet to hear anything on Band A (.15 to
.40 MHZ) I know there is something like ham radio operating down in this range somewhere, they are limited to very low power and antenna size and use a beacon like operating. I'm using a G5RV antenna which is basicially a 102ft dipole. Part of my problem is I don't what I'm listening for and probably skipping over the area where the beacons are. If I could hear something I'd like to put my own transmitter on. Ok back to searching for answers.
Jerry - NR5A Re: Newbie
Posted by Warren K2ORS/WD2XGJ on May 09, 2006 at 08:43:58.
In reply to Newbie posted by Jerry on May 08, 2006
Hi Jerry,
Welcome to LF! There are some stations running under Part 15 of the FCC rules from 160-190 kHz, basically 1 watt dc input to the final amplifier and a 15 meter long antenna + feedline. The problem is that a G5RV is a terrible LF antenna and I'm not sure about the sensitivity of the DX-160 on LF.
For more on antennas see:
http://www.mlecmn.net/~lyle/listen/listn1.htm
http://www.mlecmn.net/~lyle/listen2/listn2.htm
Also, most stations are transmitting very slow speed cw which absolutely requires a computer + sound card see:
http://www.ussc.com/~turner/qrss1.html
There are some much higher powered experimental stations around 137 kHz, but your receiver doesn't cover down there.
More later... Re: Newbie
73 Warren K2ORS/WD2XGJ
http://www.w4dex.com/wd2xgj.htm
Posted by Warren K2ORS/WD2XGJ on May 09, 2006 at 11:03:14.
In reply to Re: Newbie posted by Warren K2ORS/WD2XGJ on May 09, 2006
Jerry,
There is a list of Lowfer operators on this website:
http://lwca.org/sitepage/part15/index.htm
However, none of them are in the Dakotas. The closest ones are probably in Minnesota or Iowa, to pick them up will require a good dedicated antenna and receiver. Longwave DX is like moonbounce, you need very good antennas and receivers as well as specialized techniques. For more tips have a look at Sheldon Remington's article "On the Art of NDB Dxing"
http://www.lwca.org/library/articles/kh6sr/index.htm
73 Warren K2ORS/WD2XGJ
Upcoming SAQ 17.2KHz Transmissions this May, June, July 2006
Posted by Todd WD4NGG on May 10, 2006 at 01:45:40.
URGENT - I just received this information from Lars Kalland SM6NM about several upcoming transmissions planned by SAQ 17.2 KHz. - There will be transmissions with the Grimeton Radio/SAQ alternatoron VLF 17.2 kHz on the following dates: No QSL reports are required except on the July 2nd transmission. RegardsGRIMETON RADIO/SAQ INFORMATION
1. May 16th at about 09:30-10:30 UTC
2. May 17th at about 09:30-10:30 UTC
3. May 18th at about 09:30-10:30 UTC
4. June 5th at 10:00 UTC
5. July 2nd. The "Alexanderson" Day. Call you back with time schedule.
Lars Kalland/SM6NM
Good luck with reception! 73 Todd WD4NGG
Re: Reminder about eBay
Posted by Mike on May 11, 2006 at 02:11:39.
In reply to Reminder about eBay posted by Webmaster on April 02, 2006
I think it is nice to other members to have items listed here and on the email reflectors rather than having to dig through a bunch of auction listings. Plus the bonus is we all know each other. Many would probably say they would rather buy from known people here rather than a Internet stranger on an auction. I know some want top dollar for their items as they may rely on this income and a more probable chance of a quick sale with an auction verses listing items here which get limited exposure.
But on the original post, yes it would be nice to list here first and have the opportunity to list here the auction ID as well as what auction site if the item doesn't sell here first.
Mike Re: Newbie
WE0H
WD2XGI
Posted by John Bogath on May 14, 2006 at 12:15:18.
In reply to Newbie posted by Jerry on May 08, 2006
Hi Jerry, Re: Upcoming SAQ 17.2KHz Transmissions this May, June, July 2006
I do not think that a "DX-160" and a G5RV are going to do the "trick" for you on the LowFER band (160-190 KHz). If you want to stick with the "DX-160", I would definitely get a good preamp, or even better, a preselector for it. These are easy to homebrew, and you will find schematics for these on some of the LW websites. Then, build yourself a loop antenna. I have had good success with a 6-foot diameter one made from plastic, water tubing (used with wells) that I covered with aluminum foil (i.e., it's a shielded loop). It has 4 turns of wire centered inside of it and is resonated with a variable capacitor. I add fixed capacitors in parallel with the variable to change bands. I would recommend that any loop that you build for LowFER monitoring be at least 3 feet in diameter, and I would highly recommend going for a 5 or 6 footer. If noise levels are high inside of your house, consider moving the loop outside and away from the house and any power-lines, etc. Fifty to 100 feet of clearance should do wonders in reducing your noise-floor.
I hope this helps you. Good luck!
Posted by Todd WD4NGG on May 16, 2006 at 07:15:52.
In reply to Upcoming SAQ 17.2KHz Transmissions this May, June, July 2006 posted by Todd WD4NGG on May 10, 2006
Was not able to hear SAQ 17.2 KHz this Tuesday morning 05/16/06 between 0530-0630 EDT. Static level was running 20 over S9 which made reception very difficult here along SC coast. We had a line of strong thunderstorms pass through here all day Monday. Was hearing Russia 18.1KHz RTTY weak, also heard 18.6KHz RTTY strong, 19.6KHz RTTY U.K. weak and 19.8KHz RTTY Australia strong. Around 0615 EDT heard long 5 second on-off dashes from Hawaii 21.4KHz strong. Will try again on Wednesday morning 0530-0630 EDT. 73 Todd WD4NGG Re: Upcoming SAQ 17.2KHz Transmissions this May, June, July 2006
Posted by Chris KD6KUI on May 16, 2006 at 11:48:16.
In reply to Re: Upcoming SAQ 17.2KHz Transmissions this May, June, July 2006 posted by Todd WD4NGG on May 16, 2006
Same exact results here in Maine. Good solid copy on the dashes from Hawaii, and I was happy that my new loop picked up Anthorn, that's one I haven't seen yet! No sign of the alpha stations, though.
Do we know for sure that SAQ even transmitted? I can't seem to find reception reports anywhere... Re: Upcoming SAQ 17.2KHz Transmissions this May, June, July 2006
Posted by Todd WD4NGG on May 16, 2006 at 22:07:30.
In reply to Re: Upcoming SAQ 17.2KHz Transmissions this May, June, July 2006 posted by Chris KD6KUI on May 16, 2006
Chris glad to see you were hearing pretty much the same things on VLF Tuesday morning 05/16. There may be another way to determine if SAQ is transmitting during their next scheduled times. There is an interesting website called WorldWide Lightning Location Network. They have a network of VLF receivers in different locations around the world. Each receiving site has a VLF receiver that scans 0-24KHz in real time with a spectogram display and is updated every 10 minutes. These are intended for lightning detection worldwide but they also receive narrowband VLF transmissions. The VLF RTTY transmissions appear as a straight slightly wavy line across the display. They have a receiver located in Skodankyla, Finland which is right next door to Sweden. Notice on their display they are receiving Norway 16.4KHz very strong. Also notice the Russian Alpha signals appear as dashes on the display. I believe if SAQ is transmitting CW it should appear as dots and dashes on the Skodankyla display at 17.2 KHz. Here is the website address : http://webflash.ess.washington.edu/
Have fun 73 Todd WD4NGG SAQ Reception Successful 05/17 @ 1015 UTC
Posted by Todd WD4NGG on May 17, 2006 at 07:17:33.
In reply to Re: Upcoming SAQ 17.2KHz Transmissions this May, June, July 2006 posted by Todd WD4NGG on May 16, 2006
Received SAQ successfully on Hilton Head Island, SC on 05/17/06 @ 1015 UTC. SAQ also plainly visible on several WorldWide Lightning Location Network remote receiver displays! I could see them at Moscow, Sodankyla, Lisbon and Sheffield. Sheffield, U.K. seemed to have best copy and the backwave was plainly visible. Also I was able to copy them here well aurally at Hilton Head Island, SC using the FRG-100 + Converter + Hagan Large Ferrite Core Loop Antenna. Copy was RST 369 around 1015 UTC - good copy except for static levels were running S9 - S9+10. SAQ sending VVV VVV VVV DE SAQ SAQ SAQ . Signals stronger than when heard on 02/19/06. I was able to capture several screenshots of SAQ on the WWLLN spectrogram displays. Will be listening again tomorrow morning 05/18 between 0530-0630 UTC. Good luck! 73 Todd WD4NGG Re: Upcoming SAQ 17.2KHz Transmissions this May, June, July 2006
Posted by Harald on May 17, 2006 at 07:19:07.
In reply to Re: Upcoming SAQ 17.2KHz Transmissions this May, June, July 2006 posted by Todd WD4NGG on May 16, 2006
It bothers me a lot, that at my hometown there is since September 2005 a broadband jam signal on 17 kHz nearly permanently which spoiled all my reception attemps! Re: SAQ Reception Successful 05/17 @ 1015 UTC
Posted by Todd WD4NGG on May 17, 2006 at 07:23:58.
In reply to SAQ Reception Successful 05/17 @ 1015 UTC posted by Todd WD4NGG on May 17, 2006
SAQ transmission times for Thursday morning 05/18 should be 0530-0630EDT or 0930-1030 UTC. SAQ Copy Good 05/18 @ 1000 UTC
Posted by Todd WD4NGG on May 18, 2006 at 06:28:12.
In reply to Re: SAQ Reception Successful 05/17 @ 1015 UTC posted by Todd WD4NGG on May 17, 2006
SAQ 17.2 KHz CW copy good this morning 05/18 from 0930-1015 so far. RST 369, sending VVV VVV VVV DE SAQ SAQ SAQ and also CQ CQ CQ DE SAQ SAQ SAQ. Static levels are more manageable this morning with static peaks only around S-7 - S-8 at times. SAQ heard nicely on both Hagan Large Ferrite Core Loop and tuned 160 meter dipole. Using FRG-100 + converter. SAQ also nicely visible on WWLLN remote VLF receiver display in Sheffield, U.K. also at Sodankyla, Finland and Moscow, Russia. Made several screen captures. 73 Todd WD4NGG Re: SAQ Copy Good 05/18 @ 1000 UTC
Posted by Alan G3NYK on May 19, 2006 at 16:57:49.
In reply to SAQ Copy Good 05/18 @ 1000 UTC posted by Todd WD4NGG on May 18, 2006
Hi Todd I didnt listen on the first scheduled day but they certainly were a good signal here on the 2nd and 3rd days. Reception by a wire stuck in the back of the PC to the sound card and Alberto's WinRad. Initial transmissions were as early as 0910z.
Yes the WWLL sites are very good for chasing VLF signals finding what is active and where it can be heard. You will see the Alphas on the Sheffield UK site when they are active.
Regards de Alan G3NYK First Hifer heard
Posted by Jerry - NR5A on May 21, 2006 at 21:36:09.
Heard my first Hifer a little bit ago. HI on 13558 at about 0100 UTC. He was a 329 to 339 slow CW.
Jerry - NR5A - South Dakota PCB info
Posted by Arthur Hernandez on May 22, 2006 at 21:45:41.
I was cleaning up by test bench and found a unpopulated PCB. It looks like a antenna pre-amp. On the trace side of the board has "W2IMB" and "by FAR". On the component side of the board MPF102 and 2N3904, 9-12V, SW1, SW2, C1 twice, and RCVR out. I can't find my Low and Medium Frequency Radio Scrapbook to look it up. Does anyone have a schematic for this pre-amp? Tried twice to contact Bill Bowers which I believe was the one who gave it to me but the emails get returned.
Respectfully,
Art
Reno, NV.
Re: PCB info
Posted by Warren K2ORS/WD2XGJ on May 22, 2006 at 22:39:52.
In reply to PCB info posted by Arthur Hernandez on May 22, 2006
Art,
I have the 9th Edition of "The Low and Medium Frequency Scrapbook" - I'll check for it and let you know.
73 Warren K2ORS/WD2XGJ
Re: PCB info
Posted by Arthur on May 23, 2006 at 00:37:12.
In reply to Re: PCB info posted by Warren K2ORS/WD2XGJ on May 22, 2006
Thanks Warren, that would be much appreciated. I can't find my scrapbook, sign of old age. New beacon
Posted by Joe Craig on May 23, 2006 at 11:19:22.
187.37 kHz N Bauline NL GN37or QRSS120, CW (VO1NA)
73 Re: PCB info
Joe
Posted by Todd WD4NGG on May 23, 2006 at 23:48:37.
In reply to PCB info posted by Arthur Hernandez on May 22, 2006
It could be the Ken Cornell (W2IMB) Regen Receiver Pre-Amp pcb made by Far Circuits. Far Circuits also made a wideband pre-amp pcb by Ken Cornell. The Regen Pre-amp was in the 9th edition scrapbook. The wideband preamp was in the August, '93 issue of Radio Fun magazine. 73 Todd WD4NGG NC
Posted by DAVID/WD4KPD on May 24, 2006 at 13:07:07.
vhfdx.net map showing big E cloud over North Carolina. have very nice print on NC squarewave.
david/wd4kpd/fm15mm
Re: Newbie
Posted by paul daulton on May 26, 2006 at 23:48:09.
In reply to Newbie posted by Jerry on May 08, 2006
One site I can recommend is www.w3eee.com Steve has a live
"grabulator" and several archives of ARGO screen captures
This site is what taught me the tecniques to get started
recieving lowfers. I got a late start this last season only managed to capture two amateur beacons. web at 427 miles and
mo at 225miles. I used a ts50 kenwood and a 75 meter dipole.
i havent copied any thing since first of march. best I understand is seqason runs nov to march. cant wait until this fall!
good luck to you
potrzebie