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Re: Beacon BRO has a top hat.
Posted by Les Rayburn, N1LF (les highnoonfilm.com) on October 01, 2000 at 23:29:05: In Reply to: Beacon BRO has a top hat. posted by Bryce Ofstie, KI0LE on September 30, 2000 at 21:42:58:
Great job! This installation looks more like a commercial NDB or lf broadcast site than a lower operation! I'm sure that BRO will be putting a big signal out of the North this year!
Re: Beacon BRO has a top hat.
Posted by John Davis on October 02, 2000 at 03:57:31: In Reply to: Re: Beacon BRO has a top hat. posted by Les Rayburn, N1LF on October 01, 2000 at 23:29:05:
::Great job! This installation looks more like a commercial NDB or lf broadcast site than a lowfer operation!::
I must agree! Bryce has done a splendid job. I've worked for commercial AM broadcasters whose towers, guys, and grounds were _far_ from looking this professionally installed. 73, John
Re: Long Wave Receiver (200-400kHz)
Posted by rich cook (rcook airstamiami.uscg.mil) on October 06, 2000 at 14:16:19:
In Reply to: Long Wave Receiver (200-400kHz) (104.html) posted by Harry Joel on August 06, 2000 at 14:05:14:
if you could send a picture and what price are you asking also have you tried to put power on it yet
Winter Schedule for TEXAS Beacon
Posted by Bill Cantrell on October 04, 2000 at 01:50:27:
Hello All, TEXAS continues to operate BPSK/CW mode on 189.700 kHz and will remain this way throughout the winter. The BPSK message is "TX(space)" for a run length of 3, MS100, ET1, for the first 30 minutes of the hour. The CW message is TEXAS AGGIES at 6 wpm for the last 30 minutes of the hour. Frequency and baud rate accuracy are +/- 0.3 parts per billion. Location: Haslet, TX, EM12 Regards, Bill Cantrell "TEXAS" & WD5CVG
VALK 137.71
Posted by DAVID G. (cn2859 coastalnet.com) on October 06, 2000 at 06:08:39:
ANYONE KNOW WHEN HE WILL BE ON FOR SURE?..... GETTING ANXIOUS ! DAVID WD4KPD/FM15 NORTH CAROLINA
NC BEACONS
Posted by DAVID G. (cn2859 coastalnet.com) on October 06, 2000 at 06:16:13:
ANYONE KNOW FOR SURE IF THESE BEACONS ARE IN OPERATION..... NC RL XP JMN MY LOCATION IN GRID FM15 SHOULD ALLOW ME TO HEAR SOMETHING ! DAVID
Re: NC BEACONS
Posted by John Davis (webmaster lwca.org) on October 06, 2000 at 18:26:10: In Reply to: NC BEACONS (165.html) posted by DAVID G. on October 06, 2000 at 06:16:13:
Hi David, These beacons are generally seasonal, and none have them have yet reported to us as being operational this year. Keep an eye on the 1750 Meter column in The LOWDOWN, as the "fall beacon roundup" is presently underway. This is the time of year when most operators begin checking in with their plans for the DX season. 73, John
New CRUNCH version with Soundcard Input
Posted by Bill de Carle VE2IQ (bill1 cgocable.ca) on October 07, 2000 at 12:15:36:
Just uploaded CRUNCH version 2.8 to my webpage at http://cafe.rapidus.net/bill1/bbs.htm It can get its input from a SB16 or ESS-688 type soundcard instead of from the more traditional Sigma-Delta Interface. While I am in a good mood :-) this software is available free for the downloading to LWCA members and anyone who reads this message. Program needs DOS (no Windows), and follows same rules as the AFRICAM program. Bill VE2IQ
1LF remote beacon on the air!
Posted by Les Rayburn, N1LF (les highnoonfilm.com) on October 08, 2000 at 18:04:15:
After a lot of work, I finally have my second beacon, 1LF on the air. It is transmitting 24 hours a day/7 Days a week on 187.300khz. The modes are CW for the first half of each hour, and then BPSK for the second half of each hour. The beacon is operated from the site of AOA, an inactive NDB beacon that used to operate at 209khz. The site is in Calera, Alabama approximately 14 air miles from the site of XMGR. The antenna is a 40 foot vertical with 8 foot diameter tophat. Ground system consists of 64 500 foot long radials buried under the site. A solar panel charges the large marine battery that powers the beacon. Maximum charging power from the panel is about 5 watts, so in theory, the beacon could run forever from this setup. I have tested reception of the BPSK signal at home, at it locks in without a problem. Even with over 60db of attenuation switched in between the antenna and receiver. Antenna current was measured at a little over 200ma with 1 watt input. From my remote "monitoring" post located an equal distance between the two beacons, it appears to be about 3db down from the XMGR beacon, but that is to be expected. (Loading coil losses, and a better ground system account for this) I'll be posting pictures and a complete story about the project soon. We are operating with the permission of Shelby County, but the beacon may not be on the air for long, possibly only for part of the DX season. So listen for this one soon!
Low Frequency Data Communication from Sewer Manhole
Posted by Larry Marsh (lbmarsh marsh-mcbirney.com) on October 10, 2000 at 14:32:35:
My company manufactures a flowmeter that measures the sewage flow from inside municipal manholes.The municipalities would like to 1) be able to "drive-by " the site and collect the stored data or 2) have the flowmeter communicate (from within the manhole) with a device that will allow the data to be sent via e-mail to the e-mail address of the local engineer. Is there a license -free band such that one can get reliable communications out of a manhole? What distance might one expect and at what power levels? Is such a product commerically available? Thank You, Larry Marsh Frederick, Maryland
Re: Low Frequency Data Communication from Sewer Manhole
Posted by Tim Brannon (KF5CQ arrl.net) on October 11, 2000 at 22:15:45: In Reply to: Low Frequency Data Communication from Sewer Manhole (170.html) posted by Larry Marsh on October 10, 2000 at 14:32:35:
LF would not be a good choice. You need equipment for one of the ISM bands (Industrial, Scientific, and Medical), and data like this is most often sent at UHF. I did a quick MSN search on "data radio" and came up with several good hits for this type of equipment. Take a look at: http://www.johnsondata.com 73, Tim KF5CQ
Beacon RB back on the air
Posted by Robert Bicking, W9RB (bicking mwci.net) on October 10, 2000 at 16:24:31:
As of Sunday, Oct.8, RB is on 186.920, CW, 24/7 except when in pursuit of rare DX on the ham bands.
unid beacons
Posted by al k2sse (k2sse gdi.net) on October 10, 2000 at 21:00:10:
hi can anyone help me identify these beacons heard at my central fl location?? SR on 243 khz. FJ on 341 khz. UIAV on 406 khz. this is the first 4 letter one i've ever heard. i've been logging off and on for many years. thanks al k2sse
Re: unid beacons
Posted by AL (K2SSE GDI.NET) on November 05, 2000 at 17:46:19: In Reply to: Re: unid beacons (174.html) posted by Dave Tomasko on October 11, 2000 at 13:22:56:
HI THANKS FOR THE INFO AND PLEASE FORGIVE ME FOR RESPONDING SO LATE. DO YOU HAVE A SOURCE FOR THIS INFORMATION THAT YOU COULD DIVULGE?? I'VE NOT HAD ANY SUCCESS WITH ALOT OF THE BEACONS I HEAR IN CENTRAL FLA. AL K2SSE MONTVERDE,FL
Re: unid beacons
Posted by Dave Tomasko (kdtomasko aol.com) on October 11, 2000 at 13:22:56: In Reply to: unid beacons (172.html) posted by al k2sse on October 10, 2000 at 21:00:10:
I have the following information on the Unids: 245:SR Sarasota FL 338:FJ Fort Myers FL Not sure about the UIAV. Was there a long dash after the V?? Dave in Chicago
Re: unid beacons
Posted by Dave Tomasko (kdtomasko aol.com) on October 11, 2000 at 14:15:58: In Reply to: Re: unid beacons (174.html) posted by Dave Tomasko on October 11, 2000 at 13:22:56:
As an after thought, if there was a long trailing dash, UIAV could be a negative key of 410:ECB El Cabo COL. Dave in Chicago
Re: unid beacons
Posted by Frank Reynolds (reynoldsf rl.af.mil) on October 11, 2000 at 06:44:57: In Reply to: unid beacons (172.html) posted by al k2sse on October 10, 2000 at 21:00:10:
Where are you? There is a 242 SY in Syracuse, NY
Dave Curry Longwave Products EXP-1750a LW transceiver
Posted by OTom kcw (cqdx4 aol.com) on October 11, 2000 at 22:34:00:
Is the EXP-1750a radio still being sold? I have seen in two places that it has stopped being shipped/sold. Does anyone have any comments about this radio? Would like to know more about it before maybe ordering one, if I still can. Thank you, Tom kcOw
Re: Dave Curry Longwave Products EXP-1750a LW transceiver
Posted by John Davis (webmaster lwca.org) on October 11, 2000 at 23:47:40: In Reply to: Dave Curry Longwave Products EXP-1750a LW transceiver (177.html) posted by Tom kcOw on October 11, 2000 at 22:34:00:
Curry Communications is listed and linked in the Vendors page at the LWCA site. You might want to check it out and jump to the Curry site for latest status of the kit and ordering information. John
Re: Dave Curry Longwave Products EXP-1750a LW transceiver
Posted by Les Rayburn, N1LF (les highnoonfilm.com) on October 11, 2000 at 23:18:06: In Reply to: Dave Curry Longwave Products EXP-1750a LW transceiver (177.html) posted by Tom kcOw on October 11, 2000 at 22:34:00:
The unit is still being sold. Look for a complete review of this transceiver in our upcoming Lowfer Documentary, to be released by year's end. From everything, I've heard a fine unit and a good value!
Vertical E measurement
Posted by David Goldak (dave goldak-exploration.com) on October 12, 2000 at 12:38:58:
Hello, I'm in dire need some help with my vertical electric field pre-amp. I am using a 2.7 m whip antenna, mounted on a wooden stake so that the distance to the mid-point of the whip is about 3.8 m - 4 m. I take the whip antenna output into an OPA627 voltage follower with no passive ciruitry prior to the voltage follwer, I use another OPA627 as a shield driver to eliminate (nearly) the cable capacitance of the doubly sheilded cable between the whip and the pre-amp located about 10 m away from the whip (inner conductor-signal, first sheild is driven, outer shield -grounded). I then use another OPA627 as a Sallen-Key type of 2'nd order low pass at about 50 kHz, I then amplify with an LT1007 after out of band signals (AM, FM etc) have been eliminated or reduced. I record 'spheric' signals from lightning discharges with a 16 bit A-to-D on both E_vertical and H_horizontal in an effort to measure the free space impedance of 377 Ohms over the bandwidth 10 Hz to 35 kHz (may only see 377 Ohms in the VLF range though where we truly have a propagating wavefield). I am confused about all the pre-amp schematics on the web which show passive circuitry prior to a FET input pre-amp. Doesn't the passive circuitry act like a voltage divider with the antenna capacitance thereby reducing the antenna output?, even worse, if one wants to restore recorded data to true units of V/m by removing the response of the pre-amp etc, the effective height of the antenna is no longer simply half the physical height due to the voltage divider effect of the passive circuitry right?, or am I incorrect about this?. Does anyone know how to properly measure E_vertical so that I can restore the recorded data to true units of V/m correctly??. Right now I don't observe the proper free space impedance of 377 Ohms so the effective antenna height must be wrong (I use the distance to the midpoint of the whip antenna as the effective height). I appreciate any help that can be given. Best Regards David Goldak
Re: Vertical E measurement
Posted by Scott Fusare (sfusare adelphia.net) on October 13, 2000 at 05:15:28: In Reply to: Vertical E measurement (180.html) posted by David Goldak on October 12, 2000 at 12:38:58:
David, I have been working along similar lines in an effort to optimize my e-field receiver. My main references have been "VLF Engineering" by Watt and "Natural VLF Radio Waves" by Okada and Iwai. So far I have come away with the following: An e-field probe can be modeled as capacitance, equivalent to the isotropic capacitance of the whip, and resistance, equivalent to the sum of the radiation and loss resistance of the whip, all in series with the signal source. At the frequencies we are dealing with (10 KHz and down) the radiation resistance is nil and the loss resistance so many orders of magnitude below the capacitive reactance that it can also be ignored. That leaves the capacitance of the probe as the only significant parameter. The isotropic capacitance of a long thin whip is approximately 10 pF / meter. This leaves us with one very high impedance source. To prevent loading , the receiver input impedance need be at least and order of magnitude higher than the antenna. This ends up being 300 Mohm at lower audio (500 Hz) for a 1 meter whip! I agree, no input filtering is possible without potentially severe signal attenuation. Also, being as the source is capacitive, the input capacitance must be very low to prevent forming a voltage divider with the already low capacitance source. In your case you have a 27 pF source feeding a chip with an input shunt capacitance (per the spec sheet) of 8 pF. That's nearly 25% of the available signal gone. Per the above references, the receiver can be characterized by the use of a "simulated antenna" - a signal generator feeding a capacitor equivalent in value to the theoretical capacitance of your antenna. Using this technique has been enlightening to say the least. I have temporarily given up on op amp followers and gone back to a source follower as it is easier to bootstrap out the input capacitance. As an aside, I find term "effective height" to be confusing as it appears to me that the meaning is really "effective length" i.e. the available signal voltage is &laqo; the whip length times the field strength. Regards Scott Fusare N2BJW
UNID
Posted by chris steele (rm3squid earthlink.net) on October 12, 2000 at 18:53:27:
i ahve a UNId on 428 to 430, seems to be transmitting VA, i ahve heard for the pastfew nights here in andrews, sc located about 15 to 20 miles from the coast of south carolina in between charleston and myrtle beach. any info will be appreciated. it transmits for 2 seconds and off for 5, heard about 0500 to 0600 utc on each day..chris steele, andrews, sc
Re: UNID
Posted by Dave Tomasko (kdtomasko aol.com) on October 12, 2000 at 19:55:10: In Reply to: UNID (181.html)posted by chris steele on October 12, 2000 at 18:53:27:
430:VA is Varder Cuba Dave in Chicago
"TEXAS" Knocked off-the-air by Lightning
Posted by Bill Cantrell (Bill.Cantrell motorola.com) on October 16, 2000 at 11:54:21:
"TEXAS" was knocked off-the-air yesterday by lightning. I am working to repair the keyer and replace a power supply. TEXAS will be down until further notice... Regards, Bill C "TEXAS" & WD5CVG
New Loading Coil
Posted by Bryce Ofstie (KI0LE) (ki0le cp.duluth.mn.us) on October 16, 2000 at 22:19:10:
I finished a new loading coil, 100 turns of #12 on a 15 1/2 inch form. Improved BRO beacon signal strength a little more. I'm also using a variometer for tuning so I no longer have any slug tuned coils in the antenna circuit. I posted a couple more pictures and descriptions to the web page (http://cp.duluth.mn.us/~ki0le).
TEXAS Beacon Back On-the-Air
Posted by Bill Cantrell (Bill.Cantrell motorola.com) on October 17, 2000 at 12:07:37:
Hello All, The TEXAS Beacon is back ON-THE-AIR. I don't know if it was a DIRECT lightning strike that took it off-the-air two days ago, but inside the house it took out a HP power supply, a fuse, and the line driver IC. Outside at the base of the tower, it took out the final device, a hex-inverter IC (exploded), and a power zener clamping device. Thank goodness for surge protection devices and IC sockets! ) TEXAS continues to operate BPSK/CW mode on 189.700 kHz and will remain ) this way throughout the winter. The BPSK message is "TX(space)" for a run ) length of 3, MS100, ET1, for the first 30 minutes of the hour. The CW ) message is TEXAS AGGIES at 6 wpm for the last 30 minutes of the hour. ) Frequency and baud rate accuracy are +/- 0.3 parts per billion. Location: ) Haslet, TX, EM12 BPSK-only and other baud rates available on special request. ) ) Regards, ) Bill Cantrell ) "TEXAS" & WD5CVG
DDS update
Posted by Johan Bodin (sm6lkm.jbeab swipnet.se) on October 17, 2000 at 12:31:43:
Controller schematic and PIC source code for G0MRF's DDS LF exciter is now available from my web page: http://home4.swipnet.se/~w-41522/minidds/minidds.html The added stuff is at the bottom of the page. The frequency range is "hardcoded" to 135.7-137.8 kHz but it is easy to change it for U.S. Lowfer operation or whatever. 73 Johan SM6LKM
Needed: National RBL-5 VLF Parts
Posted by Greg Gifford (Cleophus hiwaay.net) on October 21, 2000 at 22:03:18:
Hey, I am in great need of the high and low pass filters for a 1942 National RBL-5 VLF Receiver. If there is anyone out there that has these, or a parts set that is for sale, please give me a holler!
RBL Schematic or Manual?
Posted by Dave Curry (currycom pacbell.net) on October 22, 2000 at 03:02:34:
Does anyone happen to know where I can get a copy of an RBL schematic or manual? I'm doing some upgrading on the ol' rig but don't have any schematic. Sincerely yours- David
Re: RBL Schematic or Manual?
Posted by roger dillon (rdillontx home.com) on October 22, 2000 at 09:54:29: In Reply to: RBL Schematic or Manual? (192.html) posted by Dave Curry on October 22, 2000 at 03:02:34:
There is a gif of the RBL schematic at: http://www.nj7p.org/millist/sch/rbl.gif I don't know if the various sub-models had exactly the same schematic or not. I have yet to find a manual anywhere, but I'm sure one will turn up eventually. Good luck. Roger
Weird tones around 13kHz
Posted by Matt W. (matt psibercom.org) on October 22, 2000 at 23:58:33:
Just did my first VLF field recording and got some interesting sequenced tones around 13kHz. I was near the US Coast Guard CAMSPAC site. Could it be from one of their signals? Please take a look at my VLF page and tell me if you recognize the source! thanks! -matt http://www.psibercom.org/vlf/
Re: Weird tones around 13kHz
Posted by Matt W. (matt psibercom.org) on October 23, 2000 at 01:04:02: In Reply to: Weird tones around 13kHz (194.html) posted by Matt W. on October 22, 2000 at 23:58:33:
I should do my research! it looks like ALPHA :)
Re: Weird tones around 13kHz
Posted by Frank Reynolds (reynoldsf rl.af.mil) on October 25, 2000 at 06:35:38: In Reply to: Re: Weird tones around 13kHz (195.html) posted by Matt W. on October 23, 2000 at 01:04:02:
Is Alpha the Russian version of LORAN?
Re: Weird tones around 13kHz
Posted by Jacques d'Avignon (monitor rac.ca) on October 25, 2000 at 07:16:03: In Reply to: Re: Weird tones around 13kHz (197.html) posted by Frank Reynolds on October 25, 2000 at 06:35:38:
No. The Alpha system is similar to the Omega system that was operational for many years around the world.
WTB:Inexpensive 1750 xmtr/beacon
Posted by Charlie Vest (cvest hit.net) on October 27, 2000 at 03:39:52:
Hi, I am interested in purchasing a relatively inexpensive xmtr/beacon.Homebrew is fine.I am disabled with a neuro-muscular disease which prevents me from homebrewing any small devices that require soldering of small components.Would prefer as inexpensive as possible due to fixed income. THANKS, 73...Charlie...KC0EH...
Update of the database of Canadian NDB's
Posted by Jacques d'Avignon (monitor rac.ca) on October 29, 2000 at 08:55:08:
The databases of Canadian NDB's located on Pierre Thomson's web page, have been updated to reflect all changes up to October 5th, 2000. (http://frodo.bruderhof.com/ka2qpg/)
ranger ar 3500
Posted by chris (rm3squid earthlink.net)on October 29, 2000 at 17:57:38:
I have found info that says that the ranger can receive down to 100 khz, i am unable to get audio when i enter the freq. also i found a mod that says i can have receive from 3 meg to 30 meg, i did the mod but to no avail, i stil couldn't get any audio from any freq other than 26000 to 29999. can any one please advise.chris in andrews, sc
JDH on the air
Posted by John Hoopes (jdhatti hom.net) on October 30, 2000 at 09:02:22:
Just a short note to let you all know beacon JDH is on the air. Frequency is 184.500 as near as I can tell. Operation will be CW only 24/7. Good DXing, John/AB4MS/JDH
RB off the air during Nov.
Posted by Robert Bicking, W9RB (bicking mwci.net) on October 30, 2000 at 16:43:48:
I had planned to make some antenna improvements but not in this way! While picking up leaves with my leaf vacuum, I managed to hook a guy wire for the RB antenna and the next thing I knew, I heard a crashing noise as the antenna settled on the leaf vacuum (better that than my head!). Not too much damage other than a few bent spokes on the top hat but I decided to wait until Thanksgiving to put it up when my son and son-in-law (both tall, young and strong) will be here. I did take the opportunity to add two more circular wires to increase the top hat capacitance and hopefully, the antenna current. P. S., for those of you that are hams, I will be operating from Aruba as P40RB from Nov. 27 thru Dec. 3, CW, all bands including the ARRL 160M contest. 73, W9RB.
Reception report from Duluth, MN
Posted by Roger Magnuson (k0mvj duluth.com) on October 31, 2000 at 09:09:58:
RM copies TX for the first dx station of this season. I saw several strings of TX using arfricam starting a little after 9PM CST. I thought it might be a good night to try after checking thunderstorm.com and seeing little lightning activity around the country. The other beacons that I always copy day or night are LEK, BRO, and BK. Hoping for more DX soon... Roger
XMGR copied in MN
Posted by Lyle Koehler (k0lr arrl.net) on October 31, 2000 at 09:17:23:
Before going to bed last night, I set up the receiver and computer to "listen" for XMGR's BPSK transmissions. At a little before 0400 local time, I came into the shack and tried playing with the GRAB settings in AFRICA. With a GRAB depth of 63, XMGR was printing solid on the screen. Later analysis with COHPLAY showed that XMGR had come in several times earlier during the night, and that there were a total of 7 hits on XMGR(space) with a GRAB depth of only 3. Yesterday afternoon and again yesterday evening, TX was partial copy on the screen without the frame grabber. Also heard between 0400 and 0430 CST was OK in CW mode. In fact, I noticed that OK did not switch to BPSK at 0430.
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