KTK Mussel Rock, CA

KTK was a coast station of the Robert Dollar company and was part of a network of stations designed to communicate exclusively with ships of the Robert Dollar line, notable for their dollar sign stack insignia.  The Robert Dollar stations were eventually required to serve as common carriers and communicate with ships of any line.

See the Incredible Radio Tales section of this Web site for information about the Robert Dollar Company.

KTK operated on 500kc and 6 frequencies in the HF band using A1 and A2 emission.  The station was later absorbed by Globe Wireless which continued to operate it under the KTK call sign.  Eventually the KTK frequencies became the KFS/B frequencies and were identified as such until Globe Wireless ceased Morse operation in 1999.

We want to express special thanks to Edward Prather for his help with information about KTK.  Mr. Prather writes:

"I was the Chief Engineer for Globe Wireless from 1952 - 1960 at which time Globe was acquired by  AC&R.

Actually started working as part time  KTK Opr in 1946. Permanent in middle 1947, in 1948 was assigned to the MR Station as Transmitter Technician."

View all images as a slideshow

KTK Receive Site

 KTK Receive Site
KTK Receive Site

Aerial view of the KTK and point-to-point receive site building today.  It's the orange building to the extreme left of the photo.  It is a private residence but is severely threatened by cliff erosion which has advanced even further than shown in this photo.

Transmitter Building

 Transmitter Building
Transmitter Building

East end of the KTK/point-to-point transmitter building.

Transmitter Building

 Transmitter Building
Transmitter Building

West end of KTK/point-to-point transmitter building, close view.

Transmitter Building

 Transmitter Building
Transmitter Building

West end of KTK/point-to-point transmitter building, wide view.

Transmitter Building

 Transmitter Building
Transmitter Building

MR (Mussel Rock) tower is the 225' one that supported one end of the KTK IF (now called MF) off center fed antenna.  The other end, the east tower is identical except it is 250'.  This is probably taken around 1949. There was a two car garage on the right. Under the water tower is the line shack.  Building material was hollow red bricks with slate roof.
Photo and description courtesy of Edward Prather, ex-KTK

Transmitter Building

 Transmitter Building
Transmitter Building

South east side of KTK/point-to-point transmitter building.

Transmitter Building

 Transmitter Building
Transmitter Building

East end of KTK/point-to-point transmitter building.

Transmitter Site

 Transmitter Site
Transmitter Site

This was taken around 1953 from east of the station on the ridge. (about where the freeway is now).  It shows both the Manila and Shanghai rhombic antennas.  Each was a 3-wire curtain, on 90' poles. The view is looking west toward the ocean and Mussel Rock. Quite often people would, during low tide, wade out to Mussel Rockand get stuck there not noticing the tide returning.  The Coast Guard would have to rescue them.

 

Photo and description courtesy of Edward Prather, ex-KTK

Transmitter Site

 Transmitter Site
Transmitter Site

This is an old photo, pre 1938, showing both towers.

 

Photo and description courtesy of Edward Prather, ex-KTK

Transmitter Site

 Transmitter Site
Transmitter Site

View looking west with one of the MF towers in the foreground.

 

PW-15 Transmitter

 PW-15 Transmitter
PW-15 Transmitter

Press Wireless PW-15 transmitter obtained when Globe Wireless absorbed Press Wireless.  This transmitter is similar to those that were moved to the ex-RCA transmitter site in Bolinas, CA from the Globe Wireless transmitter site in Palo Alto, CA by the MRHS.

Globe 4001 Transmitter

 Globe 4001 Transmitter
Globe 4001 Transmitter

Globe Model 4001 2kW marine and point-to-point transmitter.

WMR34

 WMR34
WMR34

10Mc point-to-point 800 cycle ship transmitter, call sign WMR34.  However Edward Prather writes: "I might mention, noting that you have labled two of the pictures as WMR34. The Point-to-point transmitters were not given a specific call sign - they took on a call sign representing the frequency they happened to be setup for. Often over a 24 hour period a Transmitter may be shifted frequency 3 or 4 times to match propagation conditions."

WMR34

 WMR34
WMR34

Another view, 10Mc point-to-point 800 cycle ship transmitter, call sign WMR34.  Edward Prather writes: "That Transmitter was a Heintz & Kaufman (HK) Type 920. Output about 10Kw with a pair of 750TL final tubes."

Press Wireless Transmitters

 Press Wireless Transmitters
Press Wireless Transmitters

Press Wireless 850 and TEB (Navy version of PW-15) point-to-point transmitters,

Transmitter Technician

 Transmitter Technician
Transmitter Technician

This photo was taken in 1953 in the Mussel Rock (MR) transmitting station.  It shows transmitter echnician John Taylor setting up the 15 kW TEB transmitter (Navy version of the PW-15).  This Transmitter was always used to Manila.
Photo and description courtesy of Edward Prather, ex-KTK

Transmitters

 Transmitters
Transmitters

15Kw TEB point-to-point transmitter (Navy version of PW-15) on the left.  The smaller Tecrad Transmitters at the end were used on KTK at about 800w. The large transmitter on right (floor to ceiling) was the I.F. (now called M.F.) transmitter putting out about 7.5Kw. It operated on 500/436 Kc. All the Marine transmitters were controlled from the Skyline Station by KTK Operators.
Photo and description courtesy of Edward Prather, ex-KTK

Edward Prather writes: "The picture, 6th back from the end, is a good one of the A-4001 Transmitter, rated about 3 Kw with pair 450TH finals.  The serial number they used at that time "4001" mfd in 1940 and, 01, first  production equipment type for that year."

Transmitter Technician

 Transmitter Technician
Transmitter Technician

Transmitter technician John Taylor in the MR (Mussel Rock) control room adjusting frequency on one of the point-to-point transmitters.  The frequency generating units were all in the control room racks and fed to the transitters via coax.  All point-to-point ransmitters ran on FSK (Frequency Shift Keying) and for most part carried 100wpm IBM Radiotype encoding.
Photo and description courtesy of Edward Prather, ex-KTK

This is a later KTK transmitter building on the ridge above Half Moon Bay, CA.  In this photo, taken in the 1970s, it is a transmitter site for ARINC.  The tower in the background supports a VHF billboard array.  In the upper right can be seen part of a fixed log periodic antenna for HF communications.