Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login

Posted: 1/21/2013 9:37:11 AM EDT
I was wondering if anyone here is into VLF

I have a LF Converter that up converts it to the 10 mHz band.

I need to dig it out and use it with my SoftRock RX Ensemble II Receiver
Link Posted: 1/21/2013 10:01:47 AM EDT
Does having bought a book about 500 kHz and 136 kHz count?

I haven't done any listening yet, though. Are we (in the US) supposed to be getting 136 kHz transmit privileges soon?

What kind of stuff have you been finding there?
Link Posted: 1/21/2013 10:34:44 AM EDT
I used to do quite a bit of listening and NDB DXing (which will date me given that NDBs are all but gone),
also listening to the GWEN doomsday transmissions. The Icom R-71A I used had a known bug that if you
spun the dial really fast and pressed a few button combos, you could tune down into the 1 KHz range.

I tried hard to pick up the experimeter-band transmissions around 170KHz but never picked up anyone
or their beacons, only the gov't stuff.

If you're wanting to try, now is the time of year to do it. Around midnight in the dead of winter I'd
routinely be able to pick up 25- and 50-watt NDBs that were thousands of miles away.
Link Posted: 1/21/2013 10:45:18 AM EDT
Originally Posted By seek2:
I used to do quite a bit of listening and NDB DXing (which will date me given that NDBs are all but gone),
also listening to the GWEN doomsday transmissions. The Icom R-71A I used had a known bug that if you
spun the dial really fast and pressed a few button combos, you could tune down into the 1 KHz range.

I tried hard to pick up the experimeter-band transmissions around 170KHz but never picked up anyone
or their beacons, only the gov't stuff.

If you're wanting to try, now is the time of year to do it. Around midnight in the dead of winter I'd
routinely be able to pick up 25- and 50-watt NDBs that were thousands of miles away.



It has been a while since I have been down there.

We used to have a local guy running a beacon, I wanted to
make one that would send slow Morse and maybe FSK.

With the SDR radios now it should make it a lot easier.

Hopefully I an get it all hooked up and build an active antenna soon

Link Posted: 1/21/2013 10:46:30 AM EDT
Originally Posted By targetworks:
Does having bought a book about 500 kHz and 136 kHz count?

I haven't done any listening yet, though. Are we (in the US) supposed to be getting 136 kHz transmit privileges soon?

What kind of stuff have you been finding there?


When I was there before it was mostly beacons etc
Having an SDR radio now I will be able to "See" the signals

Link Posted: 1/21/2013 10:53:00 AM EDT
I got curious and just tried, there's still a NDB active near me (about 50 miles) and
heard it fine on the 43' vertical (even with the tuner set to 40M).

My Icom 7200, I just discovered, will tune down to 30 KHz. I'll have to see if I can
hear WWVB tonight if I get a break from working.
Link Posted: 1/21/2013 10:58:29 AM EDT
I use an RFSpace SDR-IQ fed by a PA0RDT active antenna up about 30ft. Mainly in the winter DX season, and this season I've logged about 30 new NDBs inlcuding my best NDB catch 323kHz, TAB, Trinidad & Tobago.

Also, regularly hearing Allouise France on 162kHz, Radio Mediterranee Int'l, Morrocco on 171kHz and Iceland on 189 kHz, mostly around local midnight.
Link Posted: 1/21/2013 12:25:59 PM EDT
Originally Posted By seek2:
I got curious and just tried, there's still a NDB active near me (about 50 miles) and
heard it fine on the 43' vertical (even with the tuner set to 40M).

My Icom 7200, I just discovered, will tune down to 30 KHz. I'll have to see if I can
hear WWVB tonight if I get a break from working.



There is one near me as well. CLB at 216 kHz. I remember hearing that beacon in the radio room in the battleship USS North Carolina.


Vulcan94
Link Posted: 1/21/2013 3:44:40 PM EDT
CLB is a blowtorch here in Central PA
Link Posted: 1/21/2013 4:57:49 PM EDT
Originally Posted By WonkDeMollyDeHonk:
CLB is a blowtorch here in Central PA


If it's a blowtorch in PA, just think what it is here in Southeastern North Carolina!


Vulcan94

Link Posted: 1/21/2013 5:09:09 PM EDT
Funny you should mention it, I've been slowly putting together information to build a broadband ULF receiver to play with at work. We've got gear that transmits & receives at 525Hz and ~1900Hz. That's Hz, not kHz, mind you. Since our gear uses BPSK, I'm curious to compare the signal with an amateur BPSK-31 signal. Antenna design should get pretty interesting. I think I'm going to end up using a "field probe" instead of a proper resonant antenna to avoid the miles of wire that would require ;-)
Link Posted: 1/21/2013 5:41:17 PM EDT
I am interested in this and I built an ensemble rx as well. I am thoroughly entranced by seeing 192khz of bandwidth at once.

I have seen a project kit somewhere that up converts to 10mhz from way down low while i was chasing something else. I will see if

I can find it again.
Link Posted: 1/21/2013 5:43:08 PM EDT
Running fldigi with the 7200 tuned down to 60 KHz. WWVB is faint but obvious on the waterfall.
Can't imagine my antenna is too efficient at these frequencies, but at least the feedline
losses are low!
Link Posted: 1/21/2013 5:50:25 PM EDT
Originally Posted By Beefington:
Funny you should mention it, I've been slowly putting together information to build a broadband ULF receiver to play with at work. We've got gear that transmits & receives at 525Hz and ~1900Hz. That's Hz, not kHz, mind you. Since our gear uses BPSK, I'm curious to compare the signal with an amateur BPSK-31 signal. Antenna design should get pretty interesting. I think I'm going to end up using a "field probe" instead of a proper resonant antenna to avoid the miles of wire that would require ;-)


When I explored doing a VLF antenna, which due to FCC regs are limited to 50' in size, the go-to
was basically a vertical with a huge loading coil on the bottom and a huge capacitance hat on
top.
Link Posted: 1/21/2013 6:53:15 PM EDT
I tried to listen down there but i have too much man made niose in my part of town....ugh. Someday i am going to move away from everyone....lol
Link Posted: 1/21/2013 7:39:31 PM EDT
[Last Edit: 1/21/2013 7:42:26 PM EDT by hdhogman]
Just getting back into LW and lower.
Used to have the ideal property, way up on a hill, had a long-wire loop about 800 feet,(total length) and a base loaded tuning coil, adjustable taps and and amp.
Liked to tune in beacons from all over the world.
And, good ground system is everything.
Link Posted: 1/21/2013 7:49:57 PM EDT
Originally Posted By seek2:
Originally Posted By Beefington:
Funny you should mention it, I've been slowly putting together information to build a broadband ULF receiver to play with at work. We've got gear that transmits & receives at 525Hz and ~1900Hz. That's Hz, not kHz, mind you. Since our gear uses BPSK, I'm curious to compare the signal with an amateur BPSK-31 signal. Antenna design should get pretty interesting. I think I'm going to end up using a "field probe" instead of a proper resonant antenna to avoid the miles of wire that would require ;-)


When I explored doing a VLF antenna, which due to FCC regs are limited to 50' in size, the go-to
was basically a vertical with a huge loading coil on the bottom and a huge capacitance hat on
top.


Thanks for the tip. I'm likely going to be doing Rx only, so antenna design is less critical. Our transmitting equipment uses magnetic loops of some sort. They are sealed inside a metal case, so it's hard to say exactly what they are. When I feel like listening to something other than my gear, I'll probably just use a random wire.
Link Posted: 1/21/2013 7:50:53 PM EDT
CLB coming in clearly in NE OH.
Link Posted: 1/22/2013 5:08:30 AM EDT
[Last Edit: 1/22/2013 5:08:44 AM EDT by Mr_Harry]
I'm thinking about building the The AMRAD Active LF Antenna unless
I can find something better (since some of the parts may be hard to find).

Link Posted: 1/22/2013 5:13:18 AM EDT
[Last Edit: 1/22/2013 5:13:56 AM EDT by WonkDeMollyDeHonk]
Originally Posted By Mr_Harry:
I'm thinking about building the The AMRAD Active LF Antenna unless
I can find something better (since some of the parts may be hard to find).





Google search Roelof Bakker, PA0RDT Antenna

I have two of them, they are the best LF to MF antenna I have used in over 20 years of DXing.
Link Posted: 1/22/2013 6:45:08 AM EDT
[Last Edit: 1/22/2013 8:03:22 AM EDT by Mr_Harry]
Originally Posted By WonkDeMollyDeHonk:
Originally Posted By Mr_Harry:
I'm thinking about building the The AMRAD Active LF Antenna unless
I can find something better (since some of the parts may be hard to find).





Google search Roelof Bakker, PA0RDT Antenna

I have two of them, they are the best LF to MF antenna I have used in over 20 years of DXing.




Thank you


I found a kit for it on eBay

Top Top