Tag Archives: Alpine

Alpine, New Jersey–My Recent Visit…


W2XMN–Armstrong’s original transmitter building built in 1937, 2010 November 6
W2XMN–Interior of building, 2010 November 6


I had the great pleasure of venturing out to Alpine, New Jersey this past Saturday. I was honored to receive an invitation from Dave Amundsen, the Director of Engineering for CSC Management (the organization who presently owns the Alpine site), to celebrate the 75th anniversary of Major Armstrong’s public demonstration of FM in 1935, through a live radio broadcast.

To be able to stand in close proximity to the original Armstrong tower was truly an incredible experience, and the engaging conversations with the many radio hams in attendance was priceless.

Steve Hemphill was kind enough to serve as a tour guide through the multitude of apparatus, including the one used to transmit the anniversary broadcast. Steve personally built a replica of Armstrong’s 42.8 Mhz FM transmitter, and has lent his helping hand to restore a variety of other instruments on the Alpine site.

The GE BT-1-B 250 watt FM broadcast transmitter that resembles an old refrigerator (photographs immediately below) is Steve’s handiwork. He purchased the GE 250 watt transmitter off Ebay back in August 2002 and refurbished it back to its original shiny and functioning glory.

GE 250 watt transmitter, 2010 November 6
Steve Hemphill with the GE 250 watt transmitter, 2010 November 6








I posted some photographs of the back interior of the GE transmitter to illuminate the amount of work involved in this project. You will see all new wiring–really quite incredible!

GE 250 watt transmitter–backside interior view, 2010 November 6
GE 250 watt transmitter–backside interior view, 2010 November 6










This particular GE transmitter originally belonged to WAVE-FM in the late 1940s and was subsequently sold to the Louisville Free Public Library for use as their transmitter at WFPL-FM, sometime in the 1950s. In 1950, public radio made its debut with WFPL when the Louisville Free Public Library became the first library in the country to obtain a radio license. They started broadcasting using a GE model BT-11-B transmitter (10 watt unit), later upgrading to the model seen here.

GE 250 watt transmitter–backside with "City of Louisville" tag, 2010 November 6


Armstrong’s tower stands as it did decades ago. The bottom of the tower has changed with the construction of a building that serves to house most of the apparatus.

Armstrong Tower, 2010 November 6
Armstrong Tower, 2010 November 6


Armstrong Tower, 2010 November 6







During World War II, Armstrong carried out contract work for the Signal Corps. The tower built for his work on radar still stands (photographs below), albeit with some modifications.

Radar Tower, 2010 November 6
Radar Tower, 2010 November 6







The W2XMN building contains a small museum housing various communications equipment. The photographs below are all from the museum.

Prototype of 30 KHz FM side-channel Multiplex Receiver, 2010 November 6
Prototype of 30KHz FM side-channel Multiplex Receiver, 2010 November 6






The 30 KHz FM side-channel multiplex receiver (photographs above), is a prototype of the receiver designed by John Bose in 1953. The receiver is described in detail in US Patent 2,835,803, issued to Bose in 1958 May 20.

Vacuum Tubes, 2010 November 6
Sample component wiring board–Part of Pulse Generator, Armstrong Experimental Radar, 2010 November 6



David Terwilliger–Radio Ham and textbook of knowledge, 2010 November 6


Double Super-het single knob, 2010 November 6















James O’Neal was kind enough to explain the meaning of Conelrad (CONtrol of ELectronic RADiation) to me. I have seen the CD triangle in a circle emblem on the back of radio apparatus and wondered what it signifies. Mr. O’Neal explained that during the Cold War Conelrad was set up to provide warnings to the public. The system was introduced in 1951, and if an alert was given, radio stations were to go off the air. Chosen stations were to move to either 640 or 1240 KHz, continually alternating so as to avoid enemy direction finding equipment capable of locking into US locations by using radio stations as beacons. In 1963, the Emergency Broadcast System (EMS) replaced Conelrad. Since 1997, the Emergency Alert System (EAS) has been used.

Also in attendance was John Nashmy, who in the aftermath of 9-11, assisted in moving a number of New York television stations to the Alpine site so they could continue broadcasting.



Closing of Station KE2XCC…

A. McCormack’s write up for the closing of Alpine, 1954 March 4, page 1

McCormack, closing of Alpine, 1954 March 4, page 2

McCormack, closing of Alpine, 1954 March 4, page 3

McCormack, closing of Alpine, 1954 March 4, page 4

On March 6, 1954, the first experimental FM station, KE2XCC (W2XMN), at Alpine, New Jersey, went off the air. Armstrong’s station had been broadcasting for over fifteen years– it was the end an an era.

I had come across quite a number of letters written to Station KE2XCC from listeners expressing great loss when the station closed. It should be recognized that for all the years Armstrong broadcast from Alpine, not one commercial was heard by his listeners. This was made possible on his own dime, of course.

I think the letters speak for themselves….

Note for documents seen above: Al McCormack was Armstrong’s longtime attorney and friend.

L.T. Alstrup, letter to KE2XCC, 1954 March 10

John Burkhart, letter to KE2XCC, 1954 March 10

D. L. Pace, letter to KE2XCC, 1954 March 9, page 1

D. L. Pace, letter to KE2XCC, 1954 March 9, page 2

Albert Willis, letter to KE2XCC, 1954 March 11, page 1

Albert Willis, letter to KE2XCC, 1954 March 11, page 2

Alan Cunningham, letter to KE2XCC, 1954 March 6

D. B. Lucas, letter to KE2XCC, 1954 March 10

Louise Godley, letter to KE2XCC, 1954 March 9

Carolyn Bedford, letter to KE2XCC, 1954 March 11

Alpine, New Jersey-Part II…

Alpine, NJ-Aerial view of 400 foot

radio tower and transmitter building, undated



As a result of some queries I received with regard to the last post, I decided station W2XMN warrants additional details (photographs and documents).

Alpine,NJ-Unidentified individuals on radio tower, undated

First, Armstrong choose Alpine as the site for his station because of the importance of height as it directly relates to the surrounding landscape, so the chosen site was 500 feet above the Hudson River, facilitating ultra frequency transmissions.

Alpine, NJ-Base of the radio tower, undated

The structure of the antenna of the Alpine station can be seen in many photographs here. Armstrong delineates the details of his tower as follows:

"The height of the tower above grade is 400 feet. The length of the three cross arms is 150 feet and their vertical separation slightly over 80 feet. The radiating members of the antenna consist of a series of seven pairs of crossed rods about 11 feet long which are mounted on a boom supported between the tips of the two upper arms. These crossed rods or ‘turnstiles’ are separated slightly less than half a wave length and are fed by a series of transmission lines which wind around the supporting member. The whole antenna is fed by an open-wire transmission line of about 500 ohms impedance which runs vertically through the center of the tower and horizontally over the transmitter building for a total distance of about 700 feet. The efficiency of transmission appears to be in the order of 90 per cent." 1

Alpine, NJ, Unidentified individuals around the construction site of tower, 1937

Alpine, NJ-Charley Fowler on construction site of radio tower, 1937

Alpine, NJ, original radio mast, 1937 December 4

Following the W2AG’ s many demonstrations by W2AG (Yonkers, New York) to members of the broadcasting industry, the Yankee Network decided to construct a station at Mt. Asnebumskit, Paxton, and Station WDRC (Hartford, Connecticut) management followed with the construction of a station on Meriden Mountain located in Meriden, Connecticut. General Electric was intrigued with Frequency modulation broadcasting and, along with Zenith, began to build FM equipment. Eventually General Electric would build it’s own FM station.

REL turnstile antenna arm correct for 42 to 50 Mc., 1941 March 7

Alpine, NJ-Exterior View of W2XMN building, undated

Skinner, Cook and Babcock builders, estimated costs for lab at Alpine, NJ, 1937 August 7

Immediately following, many more stations were constructed and applications for experimental licenses were flowing into the Federal Communications Commission (FCC).  On December 19, 1939, the FCC finally decided to look into the commercial broadcasting possibilities of FM. The Commission held hearings and as a result released the following advantages of FM:

"1) lack of static; 2) FM operates on low power and gives greater service area than an AM station with similar power; 3) FM stations do not interfere with each other (an FM receiver will accept only the strongest signal when the ratio of the desired to undesired strength is about 2 to 1, whereas in the case of AM, the ratio must at least 20 to 1 for good broadcast service); and 4) FM has definite advantages (technically, economically, quality of service) in operating low power services such as forestry, police, aircraft, etc." 2

On January 1, 1941 the FCC approved commercial FM broadcasting. When the United States entered World War II permits for FM broadcasting would come to a halt. The next battle became postwar frequency allocations.

W2XMN-Special temporary authorization for station from FCC, 1938 June 18


Alpine, NJ-Logbook, Number 2, Cover page, W2XMN, 1939 August 14 through 1940 January 31


Alpine, NJ-Logbook, Number 2, W2XMN, interior page 78, 1939 November 16


Alpine, NJ-Logbook, Number 2, W2XMN, interior page 83, 1939 November 22



Alpine, NJ-Logbook, Number 2, W2XMN, interior 139, 1940 January 22



All of the photographs, documents and logbooks you see here are available within the Edwin H. Armstrong Papers.

1. Armstrong, Edwin H. "Evolution of Frequency Modulation," Electrical Engineering, 1940 December, pp. 490.

2. Erikson, Don V.,  Armstrong’s Fight for FM Broadcasting: One Man vs. Big Business and Bureaucracy, The University of Alabama Press (University, Alabama), 1973, pp. 69.

Alpine, New Jersey…

Subsequent to Armstrong’s frequency modulation system, much of which was patented in 1933, he set out to prove its superiority over AM. He first approached RCA, offering them first option on his new invention. In the spring of 1934 he set up his system in the Empire State building and for the next few years RCA engineers, alongside Armstrong, tested FM. During the summer of 1934, tests were conducted between the Empire State building and Westhampton Beach, Long Island.  The results were excellent, but proof was needed from a site located at a further distance. The receiver was moved to Harry Sadenwater’s (RCA employee) home in Haddonfield, New Jersey, with signals heard loud and crystal clear.

H. Sadenwater Notebook–Memorandum dated 1934 June 22
H. Sadenwater’s Notebook, 1934










Still, RCA would not buy Armstrong’s frequency modulation system. So he attempted to obtain permission to build a high powered FM station in 1935 from the FCC. First, the FCC denied his request. Armstrong then retained an attorney, who was able to get the commissioners to issue an experimental license.

Armstrong began building his station in Alpine, New Jersey. He poured a large sum of money into it, selling some of his RCA stock to do so. There were no FM broadcast stations in existence (with the exception of W2AG, his longtime childhood friend Randy Runyon’s station, operating out of Yonkers, New York), hence all the apparatus would have to be built from scratch. Armstrong oversaw the project from top to bottom.

Amateur Station W2AG Log, Yonkers, New York, 1937-1938
Amateur Station W2AG Log–interior, 1937-1938

Lawrence Lessing describes Armstrong’s creation of  Alpine Station W2XMN in his biography "Man of High Fidelity: Edwin Howard Armstrong" best:

The historic significance of Station W2XMN has never been widely realized. Armstrong lavished all the care and attention to detail of which he was prodigiously capable. With this station, the first full-scale one of its kind, many basic contributions were made to ultra-shortwave communications. In the development of an antenna to operate in this relatively untried region of the radio spectrum, Armstrong spent long days at Alpine making meticulous measurements, observations and modifications in antenna design which added much to the sum of general knowledge in this area. In the development of power tubes and other vacuum tubes to operate at these frequencies, Armstrong acted as a goad. No tubes adequately designed to operate at high power in ultra-shortwaves were available when the Alpine station was contemplated. Armstrong bombarded tube manufacturers with observations, criticisms and suggestions that gradually drew forth adequate tubes. All this was part of the enormous influence which, over the years, Armstrong exercised on the development of radio. 1

Armstrong on the tower at Alpine, NJ station, undated
Interior apparatus, Alpine, NJ, undated

Station W2XMN went on the air with a regular operating schedule in July 1939. Immediately following, various other FM stations were going on the air, all under experimental licenses. These stations now wanted to go commercial and thus were applying to the FCC to do so. Finally, at the end of 1939, the FCC began to study the commercial possibilities of FM broadcast. New battles would be forthcoming with the FCC….

High power amplifier, Alpine, NJ Station, 1938 August
Single unit grid and isolation oscillator set up with solid dielectric feedback cable, Alpine, NJ Station, undated

Harry Sadenwater’s Notebooks, Amateur Station W2AG Log Book, and all photographs of Alpine, NJ Station can be found within the Edwin H. Armstrong Papers in Columbia University’s Rare Book and Manuscript Library.

1 Lessing, Lawrence, Man of High Fidelity: Edwin Howard Armstrong, J.B. Lippencott Company, Philidelphia and New York, 1956, pp. 256.