In the old days of the A/N LF range stations used for air navigation, the 5
towers at each site were square towers and each leg was insulated, in
addition each insulator had an umbrella to protect it from water and
other contaminants.
The shape of these umbrellas were simply inverted large funnel over
each insulator. I do not have any clear pictures of these umbrellas,
but we still can see a few in Canada where the old range stations we
simply converted to NDB by removing 4 towers and leaving only one as
the radiator for the NDB.
Hope this will help
Jacques
Subj: 2 in the 4X4 !
Date: 98-11-24 20:06:56 EST
From: n4zvroanoke.infi (n4zv)
I was able to copy GIR 549 this past Saturday morning, parked in
downtown Charlottesville, Virginia. NC has been solid copy mobile for
the past two weeks.
Seems like a good season shaping up.
73,
Bart
Subj: Tower base insulators.
Date: 98-11-24 16:22:33 EST
From: iguanausit (Doug Williams)
I have a question for those of you who are using towers, not tubular
TV masts but "real" towers like Rohn 25G etc., as the radiating
elements on your 1750 meter transmitters. What are you using to
insulate the tower (which is "hot"), from the base (which is
grounded)? Do tower manufacturers make some sort of insulators for
this purpose, or does one have to "homebrew" them?
I would imagine
that such an insulator would have to be quite strong to support the
weight of the tower and still provide adequate RF insulation. Are AM
broadcast band towers, which are themselves radiators, isolated from
ground?
- Doug KB4OER
Reply 1: Hi, Doug. As I recall, there have been a few LowFERs using actual tower sections. We'll hope they write in to clarify how they did it. I can, however, confirm that most AM towers are base insulated.
It's true that some are operated with the base at ground potential, and are shunt-fed. Others have been re-engineered as "folded unipoles," with an outer radiating skirt that electrically ties to the now-grounded tower, at or near the top; very handy if FM or communications antennas need to go on the tower, plus it reduces loss in ground systems. But all grounded AM broadcast towers have one thing in common: they are a significantly larger fraction of a wavelength than we can muster at LF. Without that advantage, shunt feeds and folded unipoles don't work very well.
At the other extreme, a few AM towers have multiple insulators along their height! These are sectionalized to allow modification of their current distribution, in order to achieve power gain and/or high-angle skywave reduction.
However, most AM towers do have a base insulator. This is usually made of glazed porcelain, which has excellent insulating properties, and very high compression strength (although lateral forces and torsion can cause catastrophic failure). It's typically a foot or more in length. At one end, the insulator is mounted to the base plate of the tower; and at the other, it is tipped with a metal end that usually provides for a modest amount of pivoting on the support, thus reducing lateral and torsional stresses.
As you likely already know, insulators are rated with both a strike distance (the most direct path a discharge could take through air from one end to the other), and a creep distance (the path leakage current takes along the actual surface of the insulating material). The creep distance is lengthened on small insulators, or on those subject to extreme voltages, by adding multiple circumferential ridges.
On most AM installations, having moderate feed point impedances, creep is not a problem; so a simple tapering of the insulator is sufficient. However, I mention the point because leakage currents are a greater problem at LF. In today's world, it is impossible to keep an exposed insulator entirely free of contaminants...and when these are dampened by humidity or rain, an insulator starts to look more like a resistor at LF! The magnitude of this effect is sufficient to seriously alter received signal voltages when the antenna is operated in a high-impedance (E-field) mode, as well as when transmitting.
This fact, incidentally, blows the LF atmospheric attenuation theory out of the water! (No pun intended.) The controversial LOWDOWN article that attempted to link the vh/b factor describing water vapor content of air, with changes in received signal strength from NDBs, used a base-insulated vertical E-field antenna. It's not surprising, therefore, that the resulting voltages closely tracked water vapor at the receiving site. Too closely, in fact. The presented data completely ignore the likelihood that the humidity was quite different over the several intervening distances, in several different directions from the receiver!
European amateurs on 136 kHz have documented changes in antenna efficiency with varying weather, also. Thus, it's hard to overstress the importance of a first-rate insulator for LowFER installations. I hope someone will have some good suggestions to contribute.
- John
Subj: LF to the rescue
Date: 98-11-23 23:48:15 EST
From: lylemlecmn (Lyle Koehler)
While talking to my son Bruce, W0BK Sunday morning on 75 meter SSB, a
solar flare caused a sudden loss of signal. The distance between us is
about 95 miles, a little too far for ground wave on that frequency. I
could hear Bruce in there faintly with his 100 watts, but even when I
switched to a kilowatt of CW he was having trouble copying me. No
problem; we went to the LowFER band and finished our QSO with armchair
copy (using CW). Shows you what a couple of milliwatts of effective
radiated power will do on the right band.
Lyle, K0LR
Subj: New URL for K0LR web site
Date: 98-11-23 23:41:39 EST
From: lylemlecmn (Lyle Koehler)
I've moved my web page to http://www.computerpro.com/~lyle/ Mostly
the same stuff with slight changes in format, although a couple of the
articles have been updated and audio clips of four more LowFER beacons
have been added.
The old page will still be operational for a while and will have a link
to the new page. However, files on the old page will not be updated.
Please let me know of any problems, errors or "missing links" on the new
page.
Lyle, K0LR
Subj: Reliable LF
Date: 98-11-23 19:59:38 EST
From: bhkoehlermmm
On Saturday evening Nov 21, BK had two CW QSO's with LEK after building
a De Carle Sigma Delta board. LEK gave me some pointers about the use of
the board and the Coherent software. Later that evening, I copied LEK
in BPSK MS100 ET1, my first BPSK reception. The next morning during our
regular 75 meter SSB schedule, the 75 meter band went dead but we were
able to make CW contact on LF and set-up some BPSK experiments. I copied
three long BPSK messages at MS10 ET1 with no problem. It's nice to have
LF to fall back on when 75 meters lets us down.
I hope to
have BK capable of sending BPSK in the near future. For now, BK sends 12
WPM CW with ID, windspeed, and indoor/outdoor temperatures and is keyed
with a BASIC Stamp.
Conditions have not been that great for listening on weekends, so I've
only heard LEK,SAM,RM,BRO, and OK from BK (Shell Lake WI) so far this
season. On weekdays in Maplewood, MN I have heard LEK, BK, SAM, and RM.
Noise levels are much higher in the city.
73,
Bruce BK, W0BK
Subj: copying NC
Date: 98-11-22 19:46:49 EST
From: ab4mspeachnet.campus.mci (john hoopes)
Just wanted to let Dexter know that I was copying NC tonight around 6:30 PM
EST. RST was 539 with QSB.
73
John/AB4MS/JDH
Subj: Geospace Systems VLF-12 Receiver
Date: 98-11-21 22:32:33 EST
From: ribbe001gold.tc.umn.edu (Peter Ribbens)
I have a Geospace Systems VLF-12 Receiver that, for all I know, is in
good repair. I don't want to trash it, since that seems wasteful. If you
would know anyone interested in this device for the cost of shipping and
handling, I would send it to them. If I dig around I might be able to
find a manual.
Thanks
Pete Ribbens
Subj: New e-mail address
Date: 98-11-20 17:01:57 EST
From: lylemlecmn (Lyle Koehler)
My new e-mail address is lylemlecmn.net. The k0lryahoo.com address is
still valid, but I'll be using this one most of the time.
73 from Lyle, K0LR
Subj: LF: Re: A New World Record
Date: 98-11-19 14:27:18 EST
From: tractorbihug.co.nz (David Brown)
Congratulations to GW4ALG and OH1TN for their new 1916 km record for 136
kHz.
However, you Europeans need to remember that amateur operation at LF is not
confined to just 136 kHz. We have had access to LF in ZL for several years
now but at 165 to 190 kHz.
So considering a broader definition for LF (freqs below 500 kHz would be a
good start for the definition) I believe that the world distance record for
amateur LF operation is still held, but only just!!!, by my contact on 176
kHz from ZL3 to VK7 last year (30/8/97 between 0800z and 1000z), a distance
of 1941 km.
I operated portable from Kumara Junction, West Coast, South Island and
Robert, VK7ZAL, operated home QTH from Moonah, Hobart Tasmania, using the
experimental callsign AX2TAR.
The contact was two way CW, and would have been two way SSB as well, but for
the unbelievable QRM I experienced, primarily from electric fences, at the
rural site that I operated from.
The following is the text of a packet bulletin put out just after the event
by Bob ZL2CA. "The 122 metre mast at Kumara, near Greymouth, worked very
well for Dave ZL3FJ last evening when used on 176 kHz with
100 watts. The mast has recently finished service for an
MF AM broadcast station.
Signal reports from ZL listeners were typically 20 to 50 dB
over strength 9 for the ZL3FJ 176 kHz CW transmissions.
AX2TAR operated by Robert VK7ZAL gave Dave a 599 report.
Dave gave AX2TAR a 569 report. Richard VK7RO gave ZL3FJ a
599+10 dB report.
The CW tests were carried out between 0800Z and 0900Z on
Saturday 30 August.
SSB tests were tried in the following hour, using 177.5 kHz
LSB. VK7RO gave ZL3FJ a 59+15 dB report. VK7ZAL gave Dave
a 59 report. ZL3FJ could not get useful copy of the AX2TAR
SSB transmission due to QRM from local electric fences.
ZL4MD heard parts of the AX2TAR SSB transmission, between
fading, with up to readability 2.
In summary, the Saturday evening tests achieved the first
"two way" LF CW contact between VK and ZL, the first LF SSB
copy of a ZL in VK, and the first LF SSB copy of a VK in ZL.
Further tests are planned on Sunday morning. Unfortunately
the Kumara mast is being laid to rest on Tuesday."
The following is a quote from a report from Richard VK7RO re the SSB sigs on
the Sunday morning (the following morning) as part of the regular ZL LF SSB
net on 181.4 kHz USB."I heard ZL3FJ on Sunday morning from when he started at 2241z until he
faded
into the noise (S5) at 2345. He was initially 56-7, about 6dB above the
noise and gradually faded away. 2302z 46, 2326z 35, 2343z very weak,
2345z no copy.
Sunrise here was at 2126z."
And, yes, the 400 foot mast did eventually get ' laid to rest' , but only
after the first attempt failed miserably, with all the media present!!
It finally was dropped a few weeks later, with a little more brutal
treatment of two sets of stays before hand.
73
Dave ZL3FJ
Subj: Lowfer Site
Date: 98-11-19 00:28:57 EST
From: arc5ix (David Stinson)
Just wanted to compliment you on the Lowfer site.
I've been away from longwave for almost a decade,
raising children and etc., but was once very
active indeed. I enjoyed it and will refer to it again.
--
73 DE David Stinson AB5S
Subj: First I - G QSO on 136 kHz
Date: 98-11-12 15:41:40 EST
From: spininrete.it (M. Bruno)
On November 10 in the morning I had a qso with G3YXM in slow CW. Reports
"M" (EME-like) on both sides.
Lot of buzzing QRM here; signals of Dave very clear at the end (would be an
O report).
Time 0700z thru 0738z, frequency 137.720 . Mode CW, dot time 3 seconds.
I observed no QSB, only varying local noise.
Power on both sides around 1 W ERP.
73 - Marco
Subj: QYV Frequency change
Date: 98-11-12 13:40:20 EST
From: snozsgi (Bob Sethman)
There has been a frequency change for QYV. It is now 188.790.
This should be a stable frequency, moved because of plc.
Tnx
Bob WA3QYV--QYV
Subj: KRY
Date: 98-11-12 13:45:58 EST
From: snozsgi (Bob Sethman)
Great to hear KRY on this season. Reception in Donora, Pa. is about 239
with moderate noise. Also hearing A3O and GIR.
Bob QYV
Subj: ARRl Petition
Date: 98-11-12 12:14:45 EST
From: t-levstikti (Tony Levstik)
I looked over the Petition given to the FCC to establish
a new HAM band 135-190khz. If /when/ this takes effect will the License Free low power status of this band
be eliminated ??
I was going to put up a beacon and try some experimenting but if the band is
going away for License Free operation would I be better off going up in
freq. to MEDFER operation??
Regards:
Tony Levstik
The ARRL is proposing to use the band on a shared basis, as there are other services already allocated there, and is not seeking to remove the Part 15 unlicensed service. Hams and Part 15 users already share bands at UHF and microwave frequencies, so this will not be anything new.
Of course, the ham stations will have much higher effective radiated power than we do. But I'm afraid MedFER beacons face even bigger problems as their band becomes populated with multi-kilowatt broadcasters, using far more efficient antenna systems than hams will have.
Part 15 operation will still be possible, but will probably involve more resourcefulness, accomodation, and adaptation than before.
- JHD
Subj: LEK report for November
Date: 98-11-10 22:04:34 EST
From: k0lryahoo (Lyle Koehler)
We were braced for a major winter storm today, but ended up with only
about two inches of slushy snow and lots of wind. It gave me a chance
to test the new loading coil for LEK...
My old faithful receiving loop has also been replaced by a 16-turn,
8-foot loop with a balanced preamp. Sensitivity is about the same, but the nulls off the side are
considerably better. The balanced preamp also seems fairly
resistant to overload. I can now listen to NDBs while LEK is
transmitting about 100 feet from the receiving loop... So far this season I've heard
LowFERs BK, SAM, RM, BRO, OK, TEXAS (BPSK and CW), A3O and GIR.
LEK will continue to transmit alternating 12 WPM CW and MS100, ET1
BPSK until further notice. CW is sent for the first half of each hour;
BPSK during the second half. The BPSK identifier is LEK(space)(space)
with a run length of 5.
73 from Lyle, K0LR
Subj: Change in frequency
Date: 98-11-10 09:46:41 EST
From: William.Ashlockedwards.boc (Ashlock, William)
I'm planning to temporarily move WA to 167.5 kHz and compare the signal
strength to the old 187.5 kHz at various locations that I've established in
this area. At the same time I will be looking for other signals and noise on
or near this new frequency.
I would appreciate any signal reports from you listeners out there. Should
be able to make this change by 12:00 tonight.
Bill Ashlock
Subj: magnetar effects
Date: 98-11-10 01:22:04 EST
From: nhpieee.org (Nick Hall-Patch)
The magnetar disturbance* was very badly timed, as it coincided with a major
geomagnetic storm starting 0059 UTC on 27 Aug (I believe the planetary
A-index was 112), while the information put out by W1AW says the magnetar's
effects would have been around 1022 UTC.
I'm recording nightly signal strengths of several trans-Pacific MW stations,
and for that date a couple of the signal traces are virtually nil right from
local sunset (i.e. the aurora wiped out even the normal interference from
North American MW transmitters). I suspect Matthew Francey's observations
of the visual aurora may have been due to the activity of our sun, as the
observations would have been before the magnetar's effects.
On another topic, John Lauerman's article "Monitoring the Really Lowdown",
was really fascinating, an excellent example of how an LWCA membership is
worth every penny.
best wishes,
Nick Hall-Patch (VE7DXR)
*Refers to a news item in the "LF Notebook" column in the November LOWDOWN, which also appeared on the LW Home Page during October, regarding effects similar to a solar flare but which was actually due to a gamma ray burst from a highly magnetic neutron star 20,000 light-years away.
Subj: RE: GWEN
Date: 98-11-09 10:10:59 EST
From: William.Ashlockedwards.boc (Ashlock, William)
After some more exploring over the weekend down in
the low end of the band I have found some consistently quiet areas. This in
sharp contrast to the upper end where I have sidebands of the Icelandic
power-house and other AM broadcasters to contend with. Do you know if any of
the 'regulars' are planning to transmit at the low end.
Bill
(No one has stated their plans so far. First come, first served! - JHD)
Subj: Lowfer News (GWEN)
Date: 98-11-08 16:51:37 EST
From: W0rwkktv
Those pesky old GWEN (Ground Wave Emergency Network) packet stations
that were operating from 160 to 170 KHz have just been decommissioned by
the USAF. There were over 60 stations in the network, (i think there
was one in the Black Forest).
They are now being converted into NDGPS (Nationwide Differential Global
Positioning System) and they are moving their
frequencies up to 300KHz (using RTCM Format corrections), out of the
160-190KHz Band. This removes the main obstacle to full Amateur Radio
allocation of this band.
Stations in Whitney, Nebraska and Appleton, WA are already (converted).
Chino, CA and Savannah, GA are due on in a few weeks.
All of the stations have abandoned the 160KHz Band.... Yeah.....
Paul Signorelli
w0rwkktv.com
Subj: Off to a Good Start.
Date: 98-11-08 13:38:10 EST
From: n4zvroanoke.infi (n4zv)
Receptions are picking up. So far, A3O, GIR, TH, and NC. Dex is good
"daytime" copy even mobile.... using a home brew active antenna and
converter to a 2 meter multi-mode in the truck.
73,
Bart
Subj: ARRL letter
Date: 98-11-08 12:44:12 EST
From: kahrscaip.rutgers.edu (Mark Kahrs)
Hi there; do you know if it's appropriate to comment on the ARRL letter
(to the FCC that is) or just wait until the FCC issues a NPRM (if
they do). What's your opinion? Personally, I'm steamed they designed
the lowfer band for the brass key crowd. Technicians need not apply.
And they wonder why I'm not a member.
All the best,
Mark.
Reply 1: It is best to wait until the FCC has issued an NPRM or else a Notice of Inquiry (NOI), so there will be a docket number to reference. They will announce this at their Web site (www.fcc.gov), and will very likely provide for e-mail comments and responses. - JHD
Subj: BPSK Baud Rate Change for TEXAS
Date: 98-11-07 23:48:40 EST
From: QA0057email.mot (William Cantrell)
Hello Once Again,
I have modified the De Carle / Koehler keyer. CW speed is now
independent of BPSK Baud rate, and MS25 capability has replaced MS10.
Here is the new schedule for "TEXAS" for the winter `98 -`99 DX season.
Baud rate is set to MS100 and the CW speed is forever "fixed" at 6 wpm.
LowFER "TEXAS" (Haslet, TX grid EM12) is now transmitting alternate BPSK
and CW on 189.900 kHz. BPSK is sent during the *first* 30 minutes of
each hour, and CW (6 wpm) is sent for the last 30 minutes. The BPSK
format is MS100, ET1, and the identifier is TEXAS(space)AGGIE(space),
with a run length of 12. The CW ID is "TEXAS AGGIES".
For experimental purposes, BPSK can be sent at any of the following
speeds: MS5, MS25, MS50, MS100, MS200, MS500, or MS1000. Frequency and
baud rate accuracy are +/- 3 parts in 10 billion. If you would like a
special format, just let me know. I can also send CW-only or
BPSK-only. Note that the 30 minute sequencing shown above is the exact
opposite of Lyle's LEK Beacon, at the same MS100 baud rate. This way,
DXers can copy either station on alternating half-hour segments.
(Please disregard old emails, and sorry for so many notices.)
--
Regards,
Bill Cantrell WD5CVG
Subj: Beacon NC 187.050 On Air
Date: 98-11-07 19:55:46 EST
From: dmcintyreatt (Dexter McIntyre W4DEX)
Today I placed the coil back on the building roof and activated LF
beacon "NC" on 187.050 KC. Reception reports will be appreciated.
73, Dex
Subj: JDH update
Date: 98-11-07 18:43:49 EST
From: ab4mspeachnet.campus.mci (john hoopes)
Just a short note to let everyone know JDH is cranking away at 8 wpm on
184.5. I'm having problems with my clunker laptop which I use to generate BPSK so that
mode will be on hold untill further notice.
Talked with RED this afternoon and he told me that his beacon is transmitting at 185.5 and not 185.0 as listed in the LOWDOWN.
73s
John/AB4MS/JDH
Subj: KRY
Date: 98-11-07 06:29:27 EST
From: mustangkickit.pgh (Mike Lamanna)
Hey all I heard KRY on this morning on 175.48 khz..sig was weak ..but
readable with Joe's address heard it 11/7/98 at 11:25 UTC
Mike A3O
Subj: First LowFERs of season
Date: 98-11-06 10:58:08 EST
From: bickingmwci (rbicking)
Heard OK at 1159Z on 11/6 with LEK later at 1208Z. Both abt 539. OK seemed
loudest on my E-W beverage and LEK best using NW-SE.
73.
Subj: LowFER Reception
Date: 98-11-05 20:52:41 EST
From: RLLaneyaol
Today I was out driving to test the range of RL. In the process I did some listening at a fairly quiet spot at Sky Meadows State Park, which is at the foot of the Blue Ridge about 50 miles west of Washington, DC near the town of Paris, Virginia. I copied A3O in Monroeville, PA at 339 and GIR in New Eagle, PA at 439. Both are about 140 miles from the state park. Not bad. In addition, I copied QYV on 187.8 at 229.
For the past week or two here at home, I have copied some broad band verrrrry slow CW that seems to be at different places in the LowFER band at different times. I have also heard this signal in the lower part of the aero band. It seems to be a series of V's with some S's and 4's, maybe like S4VV4VVVVV. Not completely sure of the copy. Has anyone else heard this signal. Maybe a dirft net?
73,
Bob
Subj: Lowfer beacon QYV update
Date: 98-11-04 21:56:38 EST
From: snozsgi (Bob Sethman)
Beacon ID- QYV
Name-Bob Sethman
Donora, Pa. 15033
Beacon freq. 188.165 kHz
Schedule- 24/7 Mode- cw
Location- 40.177590 N, 79.86280 W
Grid Locator- FN00
Subj: LF: EA8 trip
Date: 98-11-05 12:31:39 EST
From: rik.strobbefys.kuleuven.ac.be (Rik Strobbe)
Forwarded Message: Sender: owner-rsgb_lf_groupblacksheep.org
Got my Xmas hollyday arranged by now, I will be in EA8 from 30 december 98
until 6 january 99.
QTH will be Arguineguin at the southern coast of Gran Canaria
(15°41W-27°48N = IL27DT).
Distance to UK/EI is in the 2800-3200km range, closest active LF stations
are GW4ALG and G3LDO both at 2860km. G3YXM is at 2960km, EI0CF at 3120km.
The good thing is that for all stations the path will be almost completely
over salt water.
On HF I can be QRV on 20 and 40 with a TS440 + dipole, for LF (receive
only) I will try to take a foldable loop with me (any design suggestions ?)
to use with the TS440. Callsign will EA8/ON7YD.
I will have a PC (so can try QRS tests with the GRAM software) and e-mail
acces so there will be some feedback via this reflector.
Any idea if I will have to expect LORAN troubles ? From experiences on 160
I know that QRN levels can be high, even in winter.
My dad (ON8RI) is already there and although I cannot turn him into a LF
enthousiast he promised me to check on the 138kHz signal (just using his
40m dipole as a T-antenna but without any loading coil) in order to
determine when the best signals from Europe can be expected.
Last year I had a DCF77 clock with me, that did not lock to DCF77 during
the day but worked OK during the night. So ionospheric propagation will be
involved.
73, Rik
Rik Strobbe ON7YD
rik.strobbefys.kuleuven.ac.be
Villadreef 14 B-3128 14 Baal 14 BELGIUM (JO20IX)
Subj: ARRL LF petition
From: "Tod Olson"
Date: Wed, 4 Nov 1998 23:03:04 -0600
We should expect that there will be objection on the part of
the Power Companies even though a substantial amount of
effort was expended to see if it was possible to get their
acceptance of this proposal. At such time as this reaches
'Notice of Proposed Rulemaking' (NPRM) or 'Notice of
Inquiry' (NOI) status at the FCC a note will appear on the
FCC web site requesting comments. That is the time at which
as much comment as possible on the part of LOWFER's will be
valuable.
Tod Olson, K0TO
ARRL Director, Dakota Division
Subj: RE: LW Antenna Top Hat Construction
Date: 98-11-04 21:49:01 EST
From: bickingmwci (rbicking)
This is in reply to a message dated 11-3.
An excellent book on 160 m ham band antennas is "Antennas and Techniques
for Low Band DXing" available from the ARRL. It analyzes many different
vertical antenna loading configurations and even though 160 m is roughly
ten times higher than 1750 m, the basics apply. What is unique about the
Part 15 Lowfer operation is the restriction on antenna length to 15 m. This
amounts to only 3 degrees and the radiation resistance of a vertical this
short with no top loading will be low.
The pamphlet "Transmitting Antennas
and Ground Systems for 1750 Meters", edited by Mike Mideke, 1987; has an
article on page 18 which suggests that height of 9 m with a 6 m top hat
increasing to a height of 12 m with a 3 m top hat provides best results.
The first one should have greater capacitance allowing a smaller loading
coil. A circular top hat provides the greatest capacitance for the
constrained dimensions needed to comply with Part 15. Typical top hats can
be part of self-supporting masts and made from aluminum tubing with several
rings of copper wire to increase the capacitance.
The loading coil and
ground system are also very important and again, the wavelength precludes
using radials approaching a quarter wave.
Subj: ARRL LF petition
Date: 98-11-04 10:00:08 EST
From: k0lryahoo (Lyle Koehler)
The ARRL LF petition is available in pdf form at
http://www.arrl.org/announce/lf-pet.pdf
(Requires Adobe Acrobat 3 or later to view.)
The text of a news announcement* in the ARRL Web Extra on-line magazine
is attached below.
Lyle, K0LR
(* Excerpted somewhat. Additional news, and links to the petition in other formats, can be found on the LW Home Page. - JHD)
NEWINGTON, CT, Nov 2, 1998--The ARRL has petitioned the FCC to
create two low frequency Amateur Radio allocations at 136 kHz and at
160 kHz. "These allocations will permit experimentation with
equipment, antennas, and propagation phenomena in a small segment
of the radio spectrum that has not been available to the Amateur
Service for many years," the League's petition declared.
Specifically, the League has proposed permitting CW,
SSB, RTTY/data, and image emissions for amateurs in a 2.1-kHz
"sliver band" from 135.7 to 137.8 kHz and in a 30-kHz
segment from 160 to 190 kHz. The 135.7 to 137.8 kHz band
adheres to the European Conference of Postal and
Telecommunications Administrations (CEPT) band plan. The ARRL
has proposed allowing a transmitter output in both LF
segments of 200 W PEP, but in no case greater than 2 W EIRP
(effective isotropic radiated power). The League's
petition points out that poor antenna efficiencies and ground-loss
characteristics likely would keep EIRPs at less than 1
W. The two bands would be available to General and higher
licensees.
Hams would be secondary to the Fixed and Maritime
Mobile services in the 136-kHz allocation, and secondary to the
Fixed Service in the 160-190 kHz band. The League said
its engineering surveys suggest that hams could operate in the
two segments without causing problems to power line
carrier (PLC) systems already active in that vicinity or to
government assignments. Unallocated, Part 15 PLC systems are used
by electric utilities to send control signals, data and voice.
Calculations included with the League's filing
demonstrate how inefficient even relatively large radiators
can be on LF. For example, at 200 W TPO (transmitter power output)
and a 200 foot vertical radiator, efficiency is only in the
range of 1%,yielding up to 2 W EIRP. A more practical setup--200 W
TPO into a 100-foot vertical radiator (efficiency of 0.2%) would
yield an EIRP of between 10 and 40 mW.
Subj: LW Antenna Top Hat Construction
Date: 98-11-03 13:52:47 EST
From: (Nicklaw, Jeffrey M.)
I am trying to build a top hat for my LW antenna (187 kHz) and would like
some ideas or advice on its construction. I would appreciate any antenna
formulas for top hats or pictures to guide my construction.
Thanks,
Jeff Nicklaw
Reply 1: I'm not aware of any formulas for top hats, but there are some good pictures in various LWCA Members Pages, listed on the LW Home Page. A good place to start are Lyle Koehler's and Darwin Long's pages. Maybe some LowFER operators would also care to post some ideas for Jeff here in the LW Message Board. - JHD
Subj: 1st LW Broadcaster
Date: 98-11-02 14:36:44 EST
From: reynoldsfrl.af.mil (Frank H. Reynolds)
I heard my first LW broadcast last night in Rome NY. 252 Ireland. Music was
listenable but the voice was not too clear. It sounded like French. Beacons
popping in and out from TX, NC, and even Venezuala. I still haven't heard a
lowfer though.
Frank H. Reynolds
Subj: INSPIRE team 19 planned outings
Date: 98-11-01 15:46:47 EST
From: kc6qpoqnis (Laurence E. Kramer)
Here is Team 19's plan for Very Low Frequency data taking in November.
click on the updated planned outings link.
Team 19 website
(Late November is one of the two times each year when organized monitoring efforts are conducted by Project INSPIRE. The LW Home Page will have more information by mid-month, but you may want to check the links on Team 19's page in the meantime.)
Subj: ARRL LF petition
Date: 98-11-01 08:48:21 EST
From: wilderclark (Dick Wilder (K3DI))
The ARRL LF petition has been submitted to the FCC. I understand it requests all emissions that are allowed on the
160 meter band and a maximum transmitter power of 200 Watts output though
the EIRP may not exceed 2 Watts.
73,
Dick Wilder, K3DI