The "CT" LowFER Beacon
Formerly operating on 177.750 KHz (mostly)

Note:  Click on any picture to get a larger version
FCC Rules permitting LowFER Operations:

Sec. 15.217  Operation in the band 160-190 kHz. 

(a) The total input power to the final radio frequency stage (exclusive of filament or heater power) shall not exceed one watt. 

(b) The total length of the transmission line, antenna, and ground lead (if used) shall not exceed 15 meters. 

(c) All emissions below 160 kHz or above 190 kHz shall be attenuated at least 20 dB below the level of the unmodulated carrier. Determination of compliance with the 20 dB attenuation specification may be based on measurements at the intentional radiator's antenna output terminal unless the intentional radiator uses a permanently attached antenna, in which case compliance shall be demonstrated by measuring the radiated emissions.

What Is A LowFER beacon?

The word LowFER is a pseudo-acronym that stands for Low Frequency Experimental Radio and the basis of this facet of radio experimenting is based on FCC rules 15.217 (see sidebar) which allow unlicensed operation within these rules.  Over the years, there have been many beacons operated and, more recently, a petition to create an amateur radio band in that frequency range (see the links to related pages  - particularly the AMRAD link, below.)

As can be read into the FCC rules, the limitations currently put on LowFER operations are quite severe:  It is extremely difficult to make a 15 meter antenna operating the 160-190 KHz range radiate efficiently - not to mention the 1 watt power restriction!

Nevertheless, these are part of the challenge.  Despite these restrictions, impressive DX has been achieved on the LowFER band with these restrictions, including California-Hawaii and transcontinental DX (I personally was able to receive the 8LXJ beacon from Ohio when I lived in Flagstaff, Arizona on at least one occasion.)  Traditionally, CW has been used as it is an effective narrowband mode and takes no sophisticated equipment to receive.  More recently, modes such as QRSS (Extremely low-speed CW - go here to read more about QRSS operation) and BPSK (Bi-Phase Shift Keying) have begun to see increased usage.

Being non-licensed operation, most LowFERs (many of which just happen to be amateur radio operators) use a few letters from their amateur callsign, or their initials.  While I know of no specific laws against using an amateur callsign in non-licensed operation, I (and most other operators) have refrained from doing so.  What about a portion of a callsign?  I see nothing wrong with that (a portion doth not a callsign make...) and it may make it possible to work out who really operates the beacon in the absence of other information.
LowFER Beacons on the air from Utah

Fairly recently, two different LowFER beacons operated from Utah:

- FAW - on 184.4 KHz, this beacon was operated by Chris Spencer, WB7FAW from Riverton, Utah.  This has not been heard recently.
- In the past, ZTM - on 183.5 KHz, a beacon was operated by Pete Smith, K7ZTM, has operated from Layton, Utah.  It has not been on the air, recently.

A historical background  (or "Beacons of the Past"):

My interest in MedFER (Mediumwave Frequency Experimental Radio) and LowFER operation goes back well over a decade.  (Go here to see a growing archive of information on past "CT" LowFER beacons.) Starting in about 1986, I put my first LowFER beacon on the air from Flagstaff, AZ on 177.76 KHz.  This beacon ran CW, signing the call "CT" (my initials.)

This beacon evolved over time:  It was moved to 177.750 KHz.  I later moved to Utah and operated from there for a couple of years.  On this new frequency, I operated 10 baud CCW (Coherent CW) as well as 10 (and 1) baud BPSK using ASCII and the beacon was synthesized and kept to within 0.1 ppm of the desired frequency.  This beacon was successfully copied on CW in California on numerous occasions, and fairly consistently in Wyoming on BPSK.

I later moved again but did very little LowFER operation as the layout of the yard, available trees, etc. precluded putting up a reasonable antenna and laying a decent ground.  Instead, I put a MedFER beacon on the air on 1625 KHz. This beacon was copied over 700 miles away (this was before the "new" part of the AM broadcast band - from 1605 to 1705- was used for broadcasting.)

Times and interests change:  In recent years, I have had several opportunities to put either a LowFER or MedFER beacon on the air, but I just never got around to doing either until recently.

The big question:  Why?

Why do all of this?  Former (?) LowFER Don Pomplun (K2BIO) put it well:  "A friend asks why I would be interested in listening to weak stations that in fact don't even have anything to say.  I've found that LowFERing and ham radio can be likened to bird watching:  That answer seems to be more acceptable, even if no more explainable!"
View of the CT transmitter antenna in Bountiful, Utah showing support mast, guy rope, tophat wires, and multiple downleads
View of the "CT" transmitter antenna in Bountiful, Utah showing support mast, tophat wires, guy rope, and multiple downleads

A Brief History of my LowFER activity (Transmitting):

(Let me first mention that I do not currently have a LowFER beacon of my on on the air.  Now that I have said that...)

I put my first LowFER beacon on the air from Flagstaff, AZ on 177.76 KHz back in 1986.  This beacon, like its successors, have signed the call "CT" (my initials.)  I decided that "OEI" (or something like that) was too confusing a melange of dits and dahs to be copiable in very noisy conditions (it's my callsign, so I can decide what I want!)

As I recall, this beacon was heard (by "NVA" himself) in Pahrump, NV, well over 100 miles away.  Not great DX, but at least I was getting out.  I rebuilt the transmitter and changed the frequency to 177.750 KHz and made provisions for this transmitter to be phase-locked to an external reference, but I don't recall ever running it in that mode while I lived in Flagstaff.
View of the CT transmitter and its loading coil, atop its protective garbage can located at the base of the antenna mast
The "CT" transmitter and loading coil (atop its protective garbage can at the base of the antenna mast.)

Then I moved to Bountiful, Utah and operated from there for a couple of years on 177.750 KHz where I operated 10 baud CCW (Coherent CW) as well as 10 (and 1) baud BPSK using ASCII.  The beacon was synthesized and the frequency and timing was kept to within 0.1 ppm of the desired frequency.  This beacon was successfully copied on CW in California on numerous occasions, and fairly consistently in Wyoming on BPSK (See QSLs and pictures.)
QSL from fellow LowFER NTS who heard CT from Nevada
A QSL from fellow LowFER "NTS" verifying my reception of his beacon as well as noting his reception of mine.
(Click here to listen to the beacon's ID)
LowFER Reception and QSLs:

Over the years, I have heard several LowFERs (other than my own signal.)  As far as I know, none of these beacons are still on the air (at least at their original locations.)  All of the recordings were made at approximately 0800 UTC on 19 December, 1987.

One of the strongest (non-local) beacons was NTS (see the QSL on the sidebar) run by Dave Stinson, AB5S/7 from a location very near the Nevada test site at Mercury, Nevada.  Almost any night that the noise wasn't overwhelming, this beacon could be heard on 189.8 KHz.  Another mainstay was beacon NVA from Pahrump, Nevada (listen to beacon NVA here.)  Having a lot of empty ground (and time and energy to put up the the antenna correctly!) resulted in this beacon being audible on its 177.26 KHz frequency.
A QSL from Steve Ratzlaff showing reception of the CT beacon in Oregon.
A "QSL" from Steve Ratzlaff, AA7U, verifying his reception of "CT" at Elgin, Oregon - the same location as the 7FS beacon.

A bit farther afield was the beacon "SUK" (listen to that one here) operated by Gary Waldsmith, K4SUK from Eldorado Hills, California on 174.39 KHz.  There was beacon 7FS operated by Steve Ratzlaff (listen to it here as recorded through a 30 Hz wide audio filter centered on about 500 Hz) on 174.85 KHz from Belfair, Washington.  If you listen to this recording, you'll see that the signal was very close to the noise, taking several passes of the ID to piece it together.

Much closer to home, there was the MPM beacon operated by Mark Mallory, WB7CAK (on 175.000 KHz, I believe) and the FAW beacon on 175.703 KHz.  This latter beacon was operated by Chris Spencer, WB7FAW from Orem, Utah (and you can hear it here.)  Incidentally, Chris has put the FAW beacon on the air again, this time on 184.4 KHz from Riverton, Utah.

 These days, many of the LowFER beacons operate, in addition to plain CW, more "digital-friendly" modes such as QRSS (very slow CW), WOLF and JASON - just to name a few - that allow much weaker signals to be decoded using DSP techniques.

The following are a few links that (may) have something to do with LowFER and MedFER operation:

The "CT" MedFER beacon - A PIC-Based PSK31 MedFER beacon

"QRSS and you..." - Using absurdly low-speed CW for "communications"

Using your computer to ambush unsuspecting NDBs - A brief description of how Spectran may be used when trying to receive NDBs.

A Line-Synchronous noise blanker for VLF/LF/MF use - This blanker produces very little intermod as compared to many others.

The Longwave Club of America:  "The World of Radio Below 500 KHz" - Also covers MedFER operation

Any comments or questions?  Send an email!

This page copyright 1999 - 2008 and maintained by Clint Turner, KA7OEI and yes, I know the background is for the MedFER beacon...
This page last updated on 20081229

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