Sister station to KLFB Longwave now on-air
Posted by Ed Gelinas on May 01, 2003 at 00:36:13
KLFB Longwave A-M(164.9Khz) now has 'sister station' KHFB A-M (13.560Mhz) in full operation365/24/7
www.vlf.it update
Posted by Renato Romero, IK1QFK on May 01, 2003 at 04:18:30
a new update is on line:
THE LOCK IN MODULATION IN ULTRA LOW FREQUENCY APPLICATION by A. Ghedi (upd May 2003)
73, renato
HiFER GA in Norway this morning
Posted by Steinar Aanesland on May 03, 2003 at 04:21:09
Hi all!
I had the seasons first good copy of HiFER GA on 13.555,450 MHz in Norway 0800 local time (GMT+1h) this morning. Here is the link to the screen capture.
http://home.c2i.net/saa/Images/03_05_03/
Re: UNID
Posted by Michael Oexner on May 04, 2003 at 08:15:33
Hi Bob,
Per my database:
EZ-204.0 Newark/Lizah/Elizabeth NJ USA N40 36 26 W074 13 05
ESN-212.0 Easton MD USA N38 48 17 W076 04 10
Went through past messages on the NDBLIST reflector and found a log of of EZ-212 dating October 2000. ESN has not been reported on the list.
vy 73 + gd DX,
Michael
Re: HiFER GA in Norway this morning
Posted by Gilles Auger on May 04, 2003 at 09:28:29
Hi Steinar.
It's a pleasure to see you again.
It's good to see that GA is already up and running.
Is this Spectran, an fft artefact or the jpg compression but i can see sometime a .75 Hz split on GA ? I have take a look at other capture from you and it's the first time that i see this ?
The summer is comming here and i will probably take some time to check the GA antenne.
Thanks again for this reception report Steinar.
Gilles Auger Montreal
Re: HiFER GA in Norway this morning
Posted by John Davis on May 04, 2003 at 11:59:46
:: Is this Spectran, an fft artefact or the jpg compression but i can see sometime a .75 Hz split on GA ? ::
I have examined Steinar's captures closely, and I'm quite satisfied that it's not an artifact from the JPEG compression or the FFT algorithm. I have not observed the same phenomenon as a consistent problem in other Spectran captures, so I do not believe it is a result of the way Spectran accesses the soundcard data, either.
This is just my opinion, but I suspect that the split traces are probably the result of multipath propagation, with different ionospheric Doppler shift between the two paths. Notice how the trace splits and the frequencies diverge, then other times the two re-converge into one. This suggests a rather large and slow motion of the reflective layer, compared to the more rapid and broader ionospheric spreading of signals sometimes seen at 13.56 MHz.
John
Re: NDB antenna design
Posted by John Davis on May 04, 2003 at 14:35:32
Alan writes:
"My thoughts are if you draw a standing wave from the feed point to the end of one leg of the "T" you get a quater wave at 1000kHz. Then since the voltage at the split must be the same and the current at the other open end zero you can only draw a copy of the standing wave on the first leg on(to) the second leg... {snip} Thus a T with two 200 foot top runs will resonate at the same frequency of the "L" with the 200foot top."
The flaw in this reasoning is that one must consider both the voltage and the current standing waves. The current at the far end of either horizontal run is indeed zero. It is not, however, maximum at the feed point--it is maximum at the connection of the two horizontal wires. So, why would that not translate to maximum current at the feedpoint? Because, one cannot disregard the mirror image of the voltage standing waves...which, if the two L-sections were still independent, would indeed be of the same magnitude, but of OPPOSITE POLARITY for top sections running in opposite directions.
Hence, one has now created a halfwave dipole that just happens to have a downlead connected at the ZERO-VOLTAGE center point!
The horizontal also run has a somewhat *higher* self-resonant frequency in halfwave mode than the quarterwave self-resonance of the original L antenna. The downlead is largely irrelevant to the natural resonance of the horizontal run, and the horizontal run has no bearing on the self-resonance of the vertical run now except as the source of a lumped capacitance.
That's why a T antenna cannot be analyzed as two L's in parallel.
Regards,
John
Re: HiFER GA in Norway this morning
Posted by Stan on May 04, 2003 at 22:24:04
I have observed the same phenomenon on ON5EX test beacons on 10.140 MHZ using ARGO. I suspect John is correct and it is a combination of multi-path and doppler effects.
Re: NDB antenna design
Posted by J. Jason Wentworth on May 05, 2003 at 03:33:46
Very interesting...this is an example of what I call 'second convolution' thinking, but it makes sense. Following your reasoning to its conclusion, John, this would mean that the self-resonant frequency of a 'Tee' antenna is almost totally dependent on the length of the vertical downlead. Further, this suggests that there is some optimum ratio between the total tophat wire length and the vertical downlead height that results in the lowest possible required loading coil inductance ^and therefore the lowest loading coil loss.^ What do you think? -- Jason
Re: HiFER GA in Norway this morning
Posted by Steinar Aanesland on May 05, 2003 at 04:08:07
Hi Gilles!
I have been monitoring the 137 kHz band this winter, but now I am back on 13 Mhz.
I am not an expert on this doppler shift phenomena, but I think John has an good explanation of the .75 Hz split.
If you look at the first picture on Steve Olney web sites;
http://www.zeta.org.au/~ollaneg/ism_22m/ric_vfskcw_recept.htm
you will see another example of the same distorted signal.
Steinar
Re: NDB antenna design
Posted by Alan G3NYK on May 05, 2003 at 19:36:34
Hi John, Ah I do not dispute the fact that there are other resonances on the T configuration. It as Jason suggests the top is 400feet there is a resonance at 1250kHz or thereabouts. You might call this "windom" mode. However the whole antenna is NOT resonant at that frequency as the impedance at the feed point will be reactive!!(a quick scribble says 11uH (or j89ohms)) But there is still a natural resonance at 1000kHz where the current IS a maximum at the feed point (the bottom of the the vertical)
Lets try another mind game........make an inverted L with two lengths of wire close together in the top section. The capacity is about 400pf and the natural resonance is 1000kHz. Now split the two wires to run about 3 feet apart. You have what I think is called a flat top. it is still resonance at 1000kHz but the capacity is now about 750pF. (I know this as I have measured it on my own inverted L.) Now walk one of the top-wire ends round to make a T. The capacity stays at 750pF and the natural (lowest) resonance is still at 1000kHz). Adding top wire at that height add a ball-park 6pF per metre and it doesnt matter where the wire goes provided there is at least about 2 feet separation. This admitedly means a lower inductor to tune to LF but that was not the question. The lowest natural resonance is still determined by the length of the vertical and the longest top wire.
Now my plot is not big enough to lay out and measure a T so I could be talking rubbish, but I will need to see a measurement (not a NEC simulation) before I change my stance.
The point Jason may be making is that you now need a lower inductor to tune this aerial to LF...yes about half the size of the L. Also you get get it even lower by stringing another 400foot top wire spaced by about 2 to 3 feet. The capacity goes up to about 1400pF now. This extra wire does not need to be connected at the centre...... it has just the same effect if only connected at the ends of the original T.
Great fun this antenna stuff !!
Cheers de Alan G3NYK alan.melia@btinternet.com
Re: NDB antenna design
Posted by John Davis on May 06, 2003 at 00:04:49
I think I catch a glimmer of what you are getting at, Alan. I'm now trying to picture the situation in terms of current arising from a signal injected at the bottom of the horizontal run, rather than looking at the standing waves arising from received signals. Clearly, there is a natural resonance for a combined vertical and horizontal run, whatever the geometry of the horizontal section, where the self reactance will equal zero.
But it's hard to visualize the resonant frequency remaining the same for additional equal horizontal runs. The second wire in your example nearly doubles the capacitance of the horizontal run; but does it halve the inductance thereof in the exact same proportion? Can this remain true for various geometries, or doesn't the resonant frequency shift to some extent?
If analyzed as independent L's in parallel, that's one thing; but the real world antennas are not truly independent. They're coupled, having the downlead in common. Even if the changes in inductance and capacitance values of the horizontal runs happen to automatically offset each other, their counterparts in the vertical section remain constant. The resonance frequency of the total system, therefore, seems as if it should vary somewhat as wires are added to the top. (Not as widely as the capacitance variation, as I first supposed.)
More fundamentally, I suppose, is why would one convert an L into a T if self-resonance is the object? Whichever way one looks at it, by either Alan's approach or mine, self-resonance is a special case. Our discussion so far seems to suggest its relevance to an artificially resonated electrically short NDB antenna is pretty minimal.
Only one thing do I see in common between these two cases: In receive mode, adding a second horizontal wire in opposite direction from the first results in cancellation of voltages induced by horizontally polarized fields or tilted wavefronts. In transmit mode, the vector sum of waves from currents in the horizontal section of the T (or any other top configuration that is symmetrical about the downlead connection) is zero.
Biggest difference: When self-resonant, adding a second wire to the L does not necessarily make it more efficient. But within limits, additional top section does provide a way to make the artificially resonated version more efficient.
Regards,
John
Re: NDB antenna design
Posted by John Davis on May 06, 2003 at 01:31:42
:: Following your reasoning to its conclusion, John, this would mean that the self-resonant frequency of a 'Tee' antenna is almost totally dependent on the length of the vertical downlead. ::
As you may notice from my latest reply to Alan, my earlier reasoning may not be entirely on target. But under that reasoning, the length of the vertical section would still be only one factor; the top capacitance being the other.
:: Further, this suggests that there is some optimum ratio between the total tophat wire length and the vertical downlead height that results in the lowest possible required loading coil inductance ^and therefore the lowest loading coil loss.^ ::
As I believe both Alan and I note, the self-resonant case doesn't really say a lot about the electrically-short case.
No loading coil is required at self-resonance. But does that necessarily make a self-resonant L or T more effective, because it doesn't need a loading coil? No. Coil resistance is usually one of the *smaller* factors in total loss. Ground loss is generally the largest, and a sizeable horizontal run of antenna will often add up to more loss because more of the antenna current has to interact with the soil.
For that reason, in the self-resonant case, the most efficient proportions are 100% of the antenna vertical, 0% horizontal, and a good ground system out to 1/4 wavelength from the base.
Now, considering LowFER realities, the electrically short, artificially resonated antenna is pretty much mandated by law. Even with the 136kHz ham band, all antenna options are going to be electrically short as a practical matter. Self resonance is not an issue.
In LowFER antenna design, one uses top loading not principally for the sake of a smaller inductor, but to maximize current in the vertical section. I cannot overemphasize the necessity for doing this.
First, only the vertical section radiates, for all practical purposes. Second, if you let the current taper to zero at the top (the 100% vertical case for a shorter-than-resonant antenna), the effective height of an antenna is only half its physical height. But top loading causes at least some current to flow all the way to the top of the vertical run, thus extending the effective height of the radiating section to something nearer its physical height.
You want some top loading to maximize radiation from the vertical section. In the case of an NDB, a designer can define his coverage area based on RF current flowing in a particular length of vertical wire. That height will be limited by proximity to the runway and by materials cost. He will then pick a suitable length of horizontal section to ensure he can get the necessary value of current with a reasonable transmitter power output, and a reasonable value of loading coil. Here, he can choose any length of horizontal run that fits the available space and which does not incur diminishing returns because of added ground loss. Thus, the proportions of the antenna are largely selected on a case-by-case basis.
Many ham antennas at 136kHz will be designed much the same way, except with budget and space being more critical limiting factors.
Under Part 15, we have additional constraints. The written rules are very plain: total length of antenna, transmission line-- whether it radiates or not-- and ground connection must not exceed 15 meters at LowFER frequencies, or 3 meters for MedFERs. (Not a cylindrical volume of those dimensions, either. Sorry. The ARRL antenna book is *not* an authoritative reference on this subject. The cylindrical interpretation was proposed to the FCC in formal rulemaking at the last major revision of Part 15 during the Nineties, and they rejected it!)
Thus, for us, there is a limit within which both the vertical and horizontal parts combined must fit. And when size is so thoroughly limited, then your thought is correct: there is indeed an optimum ratio between vertical run and top length or radius.
Experiments performed by Mike Mideke, Jim Ericson, and other pioneers, suggest that in most cases about 2/3 of the total length should be vertical, and the remainder should be the radius of the top hat. Numerical models also show this to be a good tradeoff between physical height and effective height. The antenna articles at Lyle Koehler's site discuss this in some detail, as I recall.
John
Next transmissions of SAQ Grimeton
Posted by Harald on May 06, 2003 at 14:53:18
The next transmissions of SAQ Grimeton will take place on June 29th, 2003 8.30 UTC, 10.30 UTC and 12.30 UTC . Check http;//www.alexander.n.se for further information.
Re: NDB antenna design
Posted by Alan G3NYK on May 06, 2003 at 16:37:45
Hi John, Yes it is a bit hypothetical. I did hint at the advantages in my earlier message. It is not generally the case at HF where the ground penetration is much less and the losses much lower (probably antennas nearer to natural resonance than at LF, where all amateur antennas are very small) but increasing the capacity of an antenna does seriously increase the efficiency at LF. Now, I am talking externally loaded or I think you said artificially tuned. Several set of measurements I have done (also Laurie G3AQC )have confirmed that, whilst the radiation resistance increases only by a certain amount, the ground loss decreases dramatically as the capacity of the antenna is increased. Alex on the RSGB reflector did produce an equation. The problem is it doesnt fit due to the difficulty of defining the losses. However it does indicate that doubling the aerial capacity halves the loss resistance, which is in agreement with my measurements. Thus these extra wires do play a vital part. Laurie has a "meander-top" configuration with approaching 200m of wire zig-zaged across his plot. He has a capacity of 1000pF and a loss resistance down to 10 ohm. This is something he could never achieve with ground stakes or "radials" (and boy did he try!!) This is rather why Laurie is one of the stations who is heard on your side when he transmits on 136kHz.
The natural resonance is probably not very useful, but it did enable me to model top inductance loaded antennas reasonably well. Another configuration that NEC says gives no advantage!! I am a little more careful about that because it may be that the effect depends much more upon it reducing the environmental loss. (not something that can be modelled) However stuffing capacity loading wires above the inductor gave reduced ground loss again.
I missed one comment the reason for a T, I think in NDB and such may be to get the radiating vertical away from environmental losses (the masts) This is difficult with an L. Notice the tops are often caged or multiple wire flat-tops.
I found the thread was getting a bit difficult to follow. So I guess I wont bore you any more on this one.
Have fun and enjoy antenna farming
Cheers de Alan G3NYK alan.melia@btinternet.com my LF page at http://www.alan.melia.btinternet.co.uk
Re: NDB antenna design
Posted by Alan G3NYK on May 06, 2003 at 16:49:35
Ah I missed these comments. The optimum for a lowfer with a total limit of 50feet, does not allow you to optimise for ground loss.
John states that more wire in the air equals more loss. That is not what we measure over real ground at LF (136kHz) because the losses due to the wire resistance are insignificant compared with the loss in the ground. NEC simulations do not cover this accurately at LF and do lead to erroneous conclusions about the advantages of long and multiwire tops. See my other posting above.
I'd better shut up I am becomming a crashing bore !!
Have fun and hope to hear you all on 136kHz before too long
Cheers de Alan G3NYK
LowFER RB, 186.92 kHz, off for summer
Posted by Robert Bicking on May 06, 2003 at 18:27:08
My beacon is off the air and I will be retuning it for 136 kHz, assuming that the LF ham band HAS to be approved soon. I have completed a 136 kHz xmtr based on a design in the RSGB LF Experimenter's Handbook and it seems to work fine into a dummy load. 73, W9RB
Re: NDB antenna design
Posted by John Davis on May 06, 2003 at 18:29:20
:: The optimum for a lowfer with a total limit of 50feet, does not allow you to optimise for ground loss. ::
All too true. It's a series of compromises, with the objective being to find the combination which results in the least restriction of coverage.
:: John states that more wire in the air equals more loss. ::
For sake of quotational accuracy, I must protest the overly broad summarization. :-)
:: That is not what we measure over real ground at LF (136kHz) because the losses due to the wire resistance are insignificant compared with the loss in the ground. ::
This is exactly what I'm referring to...not losses in the wire, but in the ground under the wire, through which the displacement current must return to the source.
In the instance where I stated a longer horizontal run sometimes implies larger loss, I was only thinking of the L case. I did not make that clear, and I should have added that the result also depends in part on the vertical profile of the soil conductivity (what's happening farther down in the skin depth).
Elsewhere, when I referred to diminishing returns, I was thinking of larger installations where the cost and effort of an improvement in capacitance begin to increase out of proportion to the improvement in signal strength.
That could happen in an NDB installation. But hams are not going to reach that point, out of practical necessity. I agree entirely with your other post of today. Wire in the air, where Part 15 limits are no longer a factor, and where a person can cover surface area in more than just a single straight line, will spread the return current through more of the earth and result in lower loss. We do agree on this.
Sorry for being too unfocused somewhere between what I was thinking and what came out on the keyboard.
Regards,
John
Re: NDB antenna design
Posted by John Davis on May 06, 2003 at 19:32:15
Hi Alan,
When the thread split into multiple subthreads, it did become a little harder to follow, but I don't think anyone could call it boring. :) For my part, I found it a great opportunity to view some age-old antenna issues in a new light, and I especially thank you for this latest message.
We appear to agree that spreading the return current over a greater area (and hence through a greater volume) of earth is a good technique for reducing ground loss. Hams on 2200m will have a considerable advantage over Part 15 LowFERs since the absence of a total length limit will allow verticals--at least, those away from major environmental loss factors--to be much more effective than they are now at 1750m, even if the physical height cannot be raised significantly.
(It does occur to me that some readers may fixate on the capacitance part of the discussion, and later find out the hard way that there are ways of increasing capacitance that actually lower the effective height of the system, and/or which do not spread the current out adequately to reduce loss. Maximize that capacitance with wire *in the air*, friends! Otherwise you might as well buy a Crossed Field Antenna. :)
I also believe you are right on target in thinking that the elevated loading coil approach improves efficiency through reduction of local environmental losses. My own experience here in the late Nineties strongly suggested that to be the case. A lot more of my RF current made it to the top of the vertical section with an elevated coil, implying that less was being sidetracked in my nearby pine-sap-cooled, bark-covered power resistors!
Again, thanks for a most interesting and enlightening discussion.
73,
John
Re: Odd signal on 36.3 kHz
Posted by Jacques d'Avignon on May 07, 2003 at 15:38:13
Stephan, send me your e-mail directly at monitor@rac.ca
I tried to send you the file but it bounced.
Jacques
UNID
Posted by AL on May 09, 2003 at 20:25:47
I'M HEARING DADA ON 263KHZ ABOUT S6 MOST OF THE DAY HERE IN CENTRAL FLA NEAR DISNEY WORLD.
DOES ANYONE KNOW THE LOCATION OF THIS BEACON?
AL
mfj 25 b modification for lf
Posted by Larry ik3chk on May 10, 2003 at 13:10:58
anyone know the exact modificatin for MFJ 259 B antenna analizer for works to 100khz - 1000 khz. 73 de Larry
Re: mfj 25 b modification for lf
Posted by Webmaster on May 10, 2003 at 19:45:27
David Oliver (then WB6VKH, now W7DNO) wrote up an article on this very thing, which we published in The LOWDOWN and had on the Longwave BBS 'way back when.' It's in our library to this very day. Check out:
http://lwca.org/library/articles/k0lr/lfanalyz/mfj259.htm
John
Re: NDB antenna design (Tee vs inverted L resonant freq.)
Posted by Lyle Koehler on May 10, 2003 at 23:33:04
Back when I thought this thread was dead, I modeled the antennas in question (which Alan has probably done also). I realize that's cheating, but here are the results:
Inverted L with 34 foot vertical section and 200 foot horizontal section -- first self-resonance at 1.05 MHz.
Tee antenna with 34 foot vertical section and a 400 foot horizontal section, fed in the center -- first self-resonance at 0.96 MHz.
Although the presence of the other half of the tee antenna lowers the resonant frequency slightly, the effect is much smaller than some folks (including me) would have guessed!
Re: NDB antenna design (Tee vs inverted L resonant freq.)
Posted by John Davis on May 11, 2003 at 01:04:27
Interesting results, Lyle.
I wonder how much difference there would be between the L and T cases if the vertical section of the L/T comprised a different percentage of the total antenna.
Say, perhaps half the original value (17 feet), and then twice the original value (64 feet), with the total length remaining at 234 feet?
John
Argo V1 build 134
Posted by Alberto, I2PHD on May 11, 2003 at 11:16:12
Hello group
I have just uploaded Argo V1 build 134.
Main changes are (from the readme):
V1, build 134 (May 11th, 2003)
- Added time information on mouse cursor display
- Added Led to indicate capture status, clickable to change it
- Dialog for recomputing screenfull time when changing QRSS mode or speed
- The calibration function has been split for the horizontal and vertical scrolling modes
- Floor for value at cursor lowered from -120dB to -160dB
Freely downloadable from http://www.weaksignals.com
Please report bugs, malfunctions, etc. Thanks.
73 Alberto I2PHD
Re: NDB antenna design (Tee vs inverted L resonant freq.)
Posted by Lyle Koehler on May 11, 2003 at 15:38:47
I was also curious about what would happen with different ratios of vertical to horizontal segments. Here are the resonant frequencies predicted by a NEC2 based antenna modeling program for antennas made of #14 wire. The frequencies are slightly different (by less than 2 per cent) from the ones I obtained earlier with the AO software, which is based on Mininec. For the inverted L antenna, the total length is always 234 feet, giving a resonance at approximately 1 Mhz. The tee antenna has a top wire that is twice as long as the horizontal wire in the inverted L, and whose center is connected to the vertical wire.
Height = 17 feet; L ant = 1.050 MHz, T ant = 0.994 MHz
Height = 34 feet; L ant = 1.052 MHz, T ant = 0.946 MHz
Height = 68 feet; L ant = 1.054 MHz, T ant = 0.882 MHz
Height = 136 feet; L ant = 1.048 MHz, T ant = 0.858 MHz
Height = 200 feet; L ant = 1.036 MHz, T ant = 0.940 MHz
Height = 233 feet; L ant = 1.026 Mhz, T ant = 1.022 MHz
Height = 234 feet (no top wire); Freq = 1.026 MHz
When the top wire is very short, both antennas look pretty much like a quarter-wave vertical. As the height gets close to zero, the inverted L becomes an open-circuited quarter-wave transmission line, and the tee is like two such lines in parallel. Somewhere in between, when the vertical and horizontal segments of the antenna have about the same length, the extra wire in the tee antenna has the greatest effect on the self-resonant frequency.
At a lower frequency, where the antenna is not self-resonant, the additional wire in the tee antenna has a much greater effect. With a 1000 uH base loading inductor, a height of 34 feet, and a horizontal segment of 200 feet, the inverted L would resonate at about 251 kHz. The tee antenna at the same height but with a 400-foot top wire would resonate at about 187 kHz. If you increase the top wire on the inverted L to 400 feet, it would resonate at about 182 kHz. So in this case, you get almost the full "benefit" of all the wire in the tee antenna.
Beacon Activation
Posted by Walter Glazar on May 11, 2003 at 17:23:18
I am in the process of reactivating my "WI" Beacon. The new QRA is AIKEN,SC 29803. I plan to leave the beacon on 24/7 through the summer. QRG 188.7 kHz.
Re: Argo V1 build 134
Posted by Ray, W2RS on May 11, 2003 at 19:43:35
Alberto,
I was unable to install the program. When I tried, I got an error message that some files could not be installed. I was running build 132, but this version did not install. I am running Win98.
73,
Ray, W2RS
Re: Beacon Activation
Posted by John Hoopes on May 12, 2003 at 11:12:48
Hey Walt old buddy! Glad to see your going to put WI back on the air. The airwaves have too quiet without the flagship beacon pounding away. Welcome back and we'll keep and ear out for you.
Best Regards John
Re: Beacon Activation
Posted by John Davis on May 12, 2003 at 13:38:09
With WI coming back, does that mean JDH might also make a return, John?
John D.
Re: Argo V1 build 134 - problem
Posted by Alberto I2PHD (fwd) on May 12, 2003 at 14:03:34
Larry, Jay and the others having the same problem,
that problem has been identified and already corrected. On my PC it did not manifest... but anyway I have been able to reproduce and fix it. I am not releasing the correction yet, as first I want to find the cause of a small anomaly that shows only with Windows XP. Nothing serious, but I would like to understand what is causing it before releasing the amended version of Argo. Please permit me another day.
73 Alberto I2PHD
Argo V1 build 134 (2nd shot)
Posted by Alberto I2PHD (fwd) on May 13, 2003 at 01:52:12
I have uploaded the amended version of Argo V1 build 134.
Please redownload it again. I haven't changed the build number, as the only mod is a change in how a dynamic array gets allocated.
Each and every time I repeat to myself to give an adequate "burn-in" period to new software versions before releasing them, and each and every time I make the same mistake of ignoring my own advices...
Let's hope there will be no need of a 3rd try.
73 Alberto I2PHD
http://www.weaksignals.com
Re: Beacon Activation
Posted by John Hoopes on May 13, 2003 at 13:30:52
It's a possibility. I haven't taken down the LF antenna but I'm sure it's going to need some attention. I'll keep you posted.
John
Re: Beacon Activation
Posted by lloyd chastant on May 13, 2003 at 14:46:10
I noted it was Dec, 1986 that I had WI logged and qsl so will be listening to see if I can get an update on that..
de Lloyd W3NF
Re: mfj 25 b modification for lf
Posted by Larry on May 14, 2003 at 04:25:30
tank you i know this article but is no ( for me ) very clear the constrution of the two broad band loop stick
( it's critical ?? )
73 De larry ik3chk
Beacon listing
Posted by Bob Montgomery on May 14, 2003 at 09:58:08
Hi:
I have just completed a beacon listing that will be given to Bill Oliver to have printed. Bill will take the orders and ship as requested. I think printing should be completed near the end of the month, but not sure yet. Still deciding on proper format. Bob Montgomery
2-nd Rus DXpedition's Fotos (fwd)
Posted by Ed Lesnichy on May 14, 2003 at 14:43:26
Hello LF-group!
Some photos abt Siberian LF DXpedition on interesting URL:
http://136.73.ru/2rus.html
Thanks Sam RN6BN !
136.73.RU site under construction ...
73! Ed RU6LA ed@dx.ru
No LF ham band in US
Posted by Lyle Koehler on May 14, 2003 at 18:22:10
The FCC has denied the ARRL's petition for an LF ham band.
http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-03-105A1.doc
Re: Beacon Activation
Posted by Dexter McIntyre W4DEX on May 14, 2003 at 23:15:56
Hi Walt! Sure will be nice to hear WI again. I've told the story many times about our first QSO which was totally unplanned. This was my introduction to present day organized Lowfer operating. You may not recognize my name but maybe you will remember working ZIA from Stanfield, NC. I been using NC for my beacon since changing my call about 6 years ago. Great to have you back!
Dexter
Re: No LF ham band in US
Posted by Webmaster on May 15, 2003 at 00:33:02
To read the reasoning behind this off-the-wall decision without having to download the whole 1.1MB Word document, you can also obtain it in much smaller PDF and text forms from links at: www.lwca.org .
John
Re: UNID
Posted by Kevin Carey on May 15, 2003 at 15:45:45
Hello Al,
My 2003 BeaconFinder lists this as follows:
263 DA Daytona Beach, FL (Daytona Beach Int'l) Lat. 29-08-39.5N, Long. 081-08-52.0W.
73 and best LW DX,
--Kevin
FCC Ruling on LF Ham Band
Posted by Robert Bicking, W9RB on May 15, 2003 at 18:05:51
I'm very disappointed as I have operated LowFER "RB" for 6 seasons and have pretty much been heard about as far as possible. I was looking forward to a LF ham band where the increased power might make actual QSO's feasible. Being a DXer, exploring the possibilities of LF DX to Europe, etc. would have been a lot of fun. In fact, I recently completed a 136 kHz xmtr from a design in the RSGB LF Handbook and was nearly ready to get on the air. The power companies were very successful in frightening the FCC with potential problems. One might ask, why aren't there any problems resulting from present users of LF like the many aircraft NDBs?
TAG is back
Posted by John Andrews, W1TAG on May 16, 2003 at 20:02:05
TAG has returned to the air, on 185.800 kHz. Current format is QRSS30, though that will change over the weekend. As always, the current status and mode may be found at:
http://webpages.charter.net/w1tag/
John Andrews
Re: Argo V1 build 134
Posted by Ray, W2RS on May 17, 2003 at 16:59:25
Alberto,
Argo V1 build 134 (2nd shot)installed and runs on my Win98 system with no problems.
Many thanks!
73,
Ray
and in WOLF mode...
Posted by John Andrews on May 18, 2003 at 14:42:30
TAG will be running in WOLF mode for most of this week. Frequency remains 185.800 kHz. WOLF software (nothing new) may be found at:
http://www.scgroup.com/ham/wolf.html
John Andrews
Re: NDB antenna design ("Halo" Tee antenna characteristics?)
Posted by J. Jason Wentworth on May 19, 2003 at 07:51:02
Would the Tee antenna have the same or similar characteristics if the 400 foot top wires were formed into a circular or square 'halo' loop, rather like a DDRR antenna? I was inspired to ask this after seeing the helipad NDB antennas offered by the NDB manufacturers. These are square or octagonal 'long wire' loop antennas strung up around helipad perimeters, and they can be either end-fed like an L or center-fed like a Tee. The installation diagrams show both feed arrangements. -- Jason
Re: NDB antenna design ("Halo" Tee antenna characteristics?)
Posted by John Davis on May 19, 2003 at 16:03:18
These are generally not long enough to be self resonant at the operating frequency, so despite physical appearances, they do not have much in common with a DDRR electrically. Analytically, they can be viewed much the same as T or inverted-L antennas, or any other capacitively top-loaded electrically short vertical.
John
Re: TAG is back
Posted by lloyd chastant on May 20, 2003 at 08:53:10
John,I have been trying to get copy on your Wolf mode, but have tried a dozen or so captures in last couple days and so far nothing..will continue and see if there may be a breakthrough to the Maryland area--
de Lloyd W3NF
Re: Beacon Activation
Posted by AL K2SSE on May 20, 2003 at 19:27:56
HI
WILL YOUR BEACON RUN QRSS??
AL K2SSE CENTRAL FL
Re: TAG is back
Posted by lloyd chastant on May 21, 2003 at 22:42:22
Well finally had a good Wolf copy on TAG tonite(May 21 -0200z) here in Maryland ..Lost count of all the tries but all of a sudden there was the TAG HOLDEN MASS message. Interesting thing was had a copy at the 192 time and then not again until the 864 through the 1536 time.Guess was just a rapid fade or weird propagation..Will send John a copy de Lloyd W3NF
TH Beacon and TAG Wolf copy
Posted by lloyd chastant on May 21, 2003 at 22:49:29
I had a very nice copy on TH beacon(189.31) at 0130z May21 but there was much fading shortly after that..Also had a good Wolf copy on TAG a half hour later...But No copy on Walt--WI(188.7) hr yet..
de Lloyd W3NF FM19MH
TAG in Jason Mode
Posted by John Andrews on May 25, 2003 at 20:11:04
TAG is now running in Jason mode on 185.800 kHz. Jason software may be found at:
http://www.weaksignals.com
Jason provides text copy with a "signal grabbing power" roughly equal to QRSS15. No miracles are expected at this time of year!
John Andrews, W1TAG
Re: Beacon Activation
Posted by Walt Glazar, WI, W3WI on May 26, 2003 at 22:43:47
WI transmits ordinary Morse message: VVV de WI WI etc. The keyer is coherent with the carrier oscillator. Speed 15 wpm.
Re: Beacon Activation
Posted by Walt Glazar on May 26, 2003 at 22:48:37
To John: I heard JDH from this location with a good signal strength- Best regards
DSP
Posted by Bob Montgomery on May 27, 2003 at 00:50:19
I might be the last one to find this program but just in case there is someone that has not seen it yet, here is a freebie dsp filter software program that I have been using and have found to be very useful when dxing:
http://www.qsl.net/ok1rr/dsp.html
I would save the page to text format as that is the only operating instructions with the program.
Have fun.
Bob Montgomery
Signal of unidentified transmitter on 18.6kHz
Posted by Harald on May 27, 2003 at 09:57:35
On May 25th, 2003 I received a signal of an unidentified transmitter on 18.6kHz, which I never received before at my home town in Germany at 48N 43 and 8E 58 (look on the spectrogramme).
Re: FCC Ruling on LF Ham Band
Posted by Jon Schumacher, K1NV on May 28, 2003 at 07:38:45
It definitely was a major disappointment and an injustice for the FCC to rule negatively on the LF allocation (both times) without any practical consideration of the interference potential.
We operated beacons in the 160-190 KHZ band for several years in the presence of PLC systems in southern Nevada with absolutely no interference whatsoever. We had a direct line to the PLC people and never heard of any problems. In fact their systems frequently interfered with us on occasion when we were in a listening mode.
Most power companies have gone to landline and microwave control of their systems and PLC's are something of a "dinosaur." We need to keep trying and back it up with good practical data.
Whistlers - which are the best reception frequencies?
Posted by Friedrich on May 28, 2003 at 09:36:41
Which are the best reception frequencies for the reception of whistlers? Is the band between 1kHz and 10kHz or the band between 10kHz or 24kHz better?
Mailing addresses beacon stations
Posted by Al Rugel on May 28, 2003 at 13:37:14
Being a long time amateur radio/SWL fan I now want to get into longwave beacon dxing. QUESTION: How or where can I obtain postal mailing addresses for beacon stations for QSL purposes?? Do they even exist? Thanks! Al Rugel
Re: Whistlers - which are the best reception frequencies?
Posted by Mike Thompson on May 28, 2003 at 15:15:44
I always thought the band for whistlers was between .1Khz and 3Khz. I usually try and peak my whistler receivers in and around 2Khz.
Here in Florida there are not many whistlers, but the few that I do hear seem to start around 2.5Khz and drop to around 500Hz.
Re: Whistlers - which are the best reception frequencies?
Posted by John Davis on May 28, 2003 at 18:28:10
A lot of sferic activity occurs above 2.5kHz on some recordings I've heard (and seen), Mike, but it may depend on where one is listening.
On the other hand, Friedrich, a whistler is descending in frequency rather rapidly when the tone is still above about 10kHz. It doesn't have much of the sound or appearance of a whistler above that range, and it's also rather weak by comparison to man-made signals and to lightning crashes. That may be the reason why Mike gets better results with limited audio bandwidth.
John
Solar Activity, LF Propagation, Natural Radio
Posted by Shawn E. Korgan (fwd) on May 28, 2003 at 18:36:14
Date: Wed, 28 May 2003 07:43:41 -0600
From: "Shawn E. Korgan" Subject: Activity
Greetings,
Wow, there is a lot going on with the sun right now! We are at this moment experiencing the effects of one or even possible two coronal holes on the surface of the sun. Activity could be good tonight. Two X class flares have just occurred from a large sunspot that is over six earth diameters wide as already noted. If these major flares impact the earth, they will likely arrive in the next 72 hours. The chances are very good that they will impact the earth due to the sunspot that created the flares being nearly dead center on the surface of the sun (from the earth) currently!
Also, two comets were seen diving toward the sun and disintegrating! They were part of an enormous comet at one point per www.spaceweather.com. What would happen if the debris of a comet were to get caught up in a high speed solar wind stream and slam in to the earth's atmosphere? Maybe nothing?
All the best in your listening endeavors over the next several days! I will very likely be out monitoring when the flares are expected to arrive!
Shawn
Re: Mailing addresses beacon stations
Posted by Stan AK0B on May 28, 2003 at 21:42:39
Try here - these guys post beacon received lists about every day. I believe this is the subscribe address, takes about a day or so to be on the mailing list.
hfbeacons@explore.plus.com
Re: Whistlers - which are the best reception frequencies?
Posted by Mike Thompson on May 29, 2003 at 07:21:21
>A lot of sferic activity occurs above 2.5kHz on some >recordings I've heard (and seen), Mike, but it may depend >on where one is listening.
Hmmm this could very well be the reason why I hear so few whistlers in my area :D The ones I HAVE heard usually had to be dug out of the backround with cooledit pro.
>On the other hand, Friedrich, a whistler is descending in >frequency rather rapidly when the tone is still above >about 10kHz. It doesn't have much of the sound or >appearance of a whistler above that range, and it's also >rather weak by comparison to man-made signals and to >lightning crashes. That may be the reason why Mike gets >better results with limited audio bandwidth.
Well the reason I set my receivers to around 2.5Khz, is because all the material out on this subject seems to suggest that the best reception would be in this area of the spectrum.
However, I have seen some articles that deal with lightning detection that seems to center around 300Khz.
Watkins Johnson R1401A/G VLF Receiver for sale
Posted by Gerry Chafee on May 29, 2003 at 21:29:32
Hello all,
I hope that this is not considered commercial because I am just trying to get rid of some of my personal stuff. I have a WJ R1401A/G VLF receiver on sale now on eBay. I also have spare parts. I have had it for many years and it has served me well. If you are familiar with this unit, you will know that it isn't microprocessor controlled, so no spurious signals when you look in the LF to VLF bands (1KHz to 600KHz range). If you are interested, it is at: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4673&item=3027550919 .
Thanks,
Gerry
Jason speed option?
Posted by John Andrews on May 30, 2003 at 20:05:07
Responding to an inquiry I made on the Lowfer reflector, Alberto di Bene has indicated that he would look into providing a fast/normal/slow version of Jason if there was sufficient interest. My suggestion had been for the slow option as an aid for U.S. Lowfers who primarily send one-way beacon transmissions. He indicated that there had been some interest from the EU side in a faster speed for 2-way QSOs.
Anyone interested in the topic is invited to make their suggestions.
John Andrews, W1TAG
Re: Sister station to KLFB Longwave now on-air
Posted by Ed Gelinas on May 30, 2003 at 23:55:37
Currently KHFB plays non-stop music with NO i.d. 7AM-9PM local time(Ca) and long dash(770Hz) after hrs. We operate 365/24/7. If you think you've copied us, please see if you can name a song you heard and approx time you heard it. We QSL 100% and as far as we know, KHFB is currently the only A-M full timer on 22Mtr band
www.lwca.org
potrzebie