Bolinas High Power

In his wonderful book "My San Francisco Story" Cmdr. Richard Johnstone talks about the radio stations and radiomen of the San Francisco Bay Area.  When speaking of the former Marconi, then RCA, point-to-point transmitting station in Bolinas he always refers to is as "Bolinas high power", a resonant title if there ever was one.

The station began with a 230kw rotary gap in 1913 with the receive site in Marshall on the east shore of Tomales Bay.  After WWI, when the assets of the American Marconi Co. were absorbed by RCA, the spark transmitter was replaced by two Alexanderson alternators, each capable of 200kW. The Bolinas alternators operated under the call KET on a frequency of 22.9kc (13,100 meters).

Later, after the discovery of the short waves, tube transmitters were installed, connected to stacked rhombic, curtain and fishbone antennas.

By 1930 there were 24 HF circuits originating at Bolinas, each with its own three letter call.  Here are some examples:

KEB - 6825.5kc

KEL - 6860.0kc (see below for photos of the original KEL transmitter)

KEI - 10620.0kc

KKQ - 11950kc (see below for a QSL letter from KKQ)

KEM - 15490.0kc

KQG - 18000.0kc

The transition to short wave for commercial point to point work meant that the Marconi receiving station in Marshall was no longer suitable as there was not enough flat ground for the multiple antennas short wave required.  RCA send Dr. Harold Beverage to California to find a new location for the point to point receive site.  He selected an area of ranch land on the Point Reyes peninsula with room the multiple high gain antennas.  The station used triple diversity for receiving with three antennas for each circuit replicated in the A, B and C antenna fields.  The Point Reyes point to point receive site was put into service in 1929 while the KPH receive site remained at Marshall.  Both services used transmitters at Bolinas.  The KPH receive site was moved to Point Reyes when the station re-opened after WWII.

The original KPH operating room at Point Reyes was in the former lunch room toward the front of the building on the first floor.  The rear of the first floor was occupied by the batteries and charging system for the point to point receivers upstairs.  When the point to point receivers were changed to AC operation the battery room became available and KPH moved into the newly vacated area.

The RCA point-to-point service at Bolinas and Point Reyes remained in service until 1973 when the last circuit - to Tahiti - was terminated.


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This announcement of the construction of the Marconi stations at Bolinas and Marshall appeared in the April 1913 issue of Modern Electronics magazine.

The apparatus for the "power house", as the Marconi transmitter building at Bolinas was called, was largely sent to the town by schooner from San Francisco.  The Bolinas wharf had to be reinforced to handle the loads.  Once ashore the components were brought to the site in horse drawn wagons such as this one, shown ascending a hill on Mesa Road, the same road one uses today to access the site. [Note: the location of this photo is "received wisdom" and not confirmed.  The curator of the Bolinas Museum thinks it may show equipment on its way to the receive site at Marshall.  Further research is underway.]

This photo of a mule team hauling a sledge carrying cable is confirmed to be from Bolinas.  See the next photo for the inscription on the reverse of the post card.

Inscription on the reverse of the previous photo confirms the mule team was used at Bolinas.

This is believed to the the rotary spark gap, the heart of the original 230kW Marconi transmitter. The words on the casting read W MACKIE & C, 47 1/2 OLD ST, LONDON EC. Perhaps someone can drop by and see if they have a manual available.

This interior view of the power house shows what we believe to be the drive motor for the original rotary gap. The drive shaft goes through a thrust bearing and then into the circular device near the wall. At first glance it might be thought that this is the rotary gap. But we have always read that the gap was contained in a cork lined "spark chamber" to reduce noise. And indeed the drive shaft seems to extend through the wall into the next room. We speculate that the smaller drive motor seen behind the main motor may be for a backup gap but we have never read any evidence of such a backup. The belt driven machines to the left look like compressors. What appear to be coils are on the gallery above.

This wider view shows the drive motors to the left and the switchboard on the gallery above to the rear.

This apparently inconsequential photograph is actually of great historic importance. It shows the anchor for the wires of the original Marconi antenna. This anchor, along with the cement bases of the Marconi support towers and their anchor points still exist today. In this photograph the Marconi power house has yet to be built.

Here is a wonderful view of the down leads from the original Marconi antenna connected to the anchor, their insulators suspended in mid air.

This wide view of the power house shows the down leads from the Marconi antenna and possible the antenna lead cable. We are not sure what purpose the box like structure on the side of the power house had.

This photo is alleged to be from 1915. However we see the cooling tower to the south of the power house and what we believe to be the tower that supported one end of the 126kc transmitting antenna. Those items would date the photo from the time of water cooled tube transmitters, much later than 1915.

Here they are, the two magnificent Alexanderson alternators of 200kW each. See the Radio Archeology section of this Web site for details of how the plaque announcing these alternators disappeared in 1973 and was finally returned. Compare this photo to the ones showing the rotary gap drive motors. The vertical I beams behind the alternators appear to be the ones shown in those photos and the gallery may be seen above.

RCA Communications, Inc., transmitting station at Bolinas, California, showing a forest of poles and towers of different types as used for a large number of high-frequency antennas. Butt-spliced poles and A poles may be seen, together with steel towers.

Entry road to the transmitter site in Bolinas.  Three of the original nine Marconi 300ft steel antenna masts may be seen, now painted red and white.

1935 - Bolinas point-to-point HF beams, anchor point for one of the original Marconi antenna masts in foreground.

1935 - One of the original 300ft. Marconi masts.  Open wire feeders to HF antenna may be seen to the left.

RCA fishbone point-to-point antennas, Bolinas.

This photo from the Belmar, NJ station shows how the Marconi masts were constructed.

Here's a photo of the rigger's truck taken from part way up one of the Marconi masts.

This amazing photo was taken from the very top of the short strap iron mast atop the 300ft Marconi mast. The photographer had to lean way out from the mast to get this photo showing one of the guy points below. You needed brass ones to be a rigger in those days as the following photo will confirm.

In this photo from the top of one of the Marconi masts you see another mast in the distance with the small strap iron tower atop it. In the near field are what we think are the insulators and bridle for an antenna being rigged. But there may be more to the device than just an insulator. More amazing is the other rigger in a bosun's chair in the middle distance. Brass ones.

Here's a closeup of that brave rigger.

This is the first transmitter to have the call KEL.  It operated experimentally on 95 meters, then considered a short wave, as indeed it was compared to the 13100 meter wave of the alternator it was about to replace.  By 1930 KEL had been moved to 6860.0kc.

The caption says it all

QSL letter dated 1935 confirming reception of KKQ on 11950.0kc

Here's a radiogram sent via RCA from Manila to Shanghai on 2 June 1940.  Given the date we hope that the folks involved left the area before the end of 1941.

This article from the September 1946 "RCA Relay" house organ talks about how overseas program feeds were received at the Riverhead station of Radio Central and relayed to Room 402 at 64 Broad Street.  WQV was on 14800kc.

Ignore the prominent door knob and check out the Hammarlund receiver, patch panel and terminal equipment.

Point to point transmitters thought to be in Building 2, built in 1929 to compliment the new HF receive site in Point Reyes.

Collins auto tune transmitter 175Y in Building 1

Ivan and operator Bill Meloney in front of 175Y. The three wire antenna lead for MF transmitter BL-10 may be seen above Ivan's head.

Composite transmitter 78/79 (mentioned in Frank Geisel's station reports in the KPH History section of this Web site) located on the upper gallery above transmitter BL-10 in Building 1. The bowl insulators marked 78 and 79 still exist in the wall of the gallery. One of the panels shown here still exists as well. It was mounted on the wall of the bedroom of Denice Stoops by her ex-husband after it was decommissioned! Denice brought it back to the station where it now resides as an object of veneration.

The original Marconi receive station was located in Marshall (or Marshalls or Fish-O-Mens) on the east side of Tomales Bay. This view looking north from Shoreline Highway shows the Marconi hotel, cottages and one of the towers. The view is much the same today except that the road is paved. See the Radio Archeology section of this Web site for photos of the buildings and surrounding area today.

This is the view looking south along Shoreline Highway toward Point Reyes Station.

The hotel and two cottages still exist today. The steps leading right to the water are gone. Note the reference to the fish camp near the site. Passengers on the narrow gauge railroad that passed the location often bought fresh fish from the fishermen at the camp.

The Marconi hotel and power house may be seen along with the antenna masts on the ridge. The bases and guy anchors for the masts still exist. See the Radio Archeology section of this Web site for recent photos. Unlike the transmitting station in Bolinas, where power was brought in from two different substations, power for the receive station was generated on site.

This is a view of the receiving station looking north.

This is the operations building at Marshall where the actual reception of trans-Pacific signals was carried out. The signals were sent by wire line to the Central Radio Office in San Francisco. This is also the building that was occupied by the KPH marine receivers when that station moved to Marin county in the 1920s. The tower is part of the balancing antenna system, believed to be used to reduce static.

This photo is said to show Frank Geisel at the power switchboard at Marshall.

Here is a closeup of one of the two beautiful cottages at the Marshall station. One has been restored by the Marconi Conference Center, which now runs the site.

In 1929, with the advent of the short waves as a commercially viable medium, the point to point receive site moved to the Point Reyes peninsula. The site was selected for RCA by Dr. Harold Beverage to provide space for all the HF antennas that would be needed. This areal photo shows the RCA site in the center, identified by the cypress lined driveway (the trees much shorter than they are now). The KMI receive site may be barely seen to the lower left on the same side of the road as the RCA site above the ranch.

This rear quarter view of the receive building gives just a hint of how many antennas were at the site. Triple space diversity was used with three highly directional antennas aimed at the target city.

The stairs just inside the main entry of the Point Reyes receiving station leading to the point to point (Overseas) department upstairs.

Here are the men of the point to point department enjoying lunch in the combined lunch and locker room. Judging by the pot on the table they were big eaters.

The original point to point receivers at Point Reyes.

The entry door into the receiving room may be seen beyond the row of receivers.  The room is copper shielded and the doors are copper clad.  The doors remain in position today.

Here is a closeup of some of the receivers with the schedule board visable.

The overhead balanced antenna lines and Collins 51J-4 monitor receiver may be seen in this photo.

The updated installation showing the copper doors and the RCA "meatball" logo inlain in the floor.  Amazingly, the meatball survives today.  The Shanghai receiver is to the left.

This great photo shows the men and women of the point to point department with the receivers in the background, each bearing the name of the city to which it is listening.

This central console was installed at the time the point to point receivers were replaced with units designed for operation on AC.

Central console.  The only item remaining from this installation is the small storage file to the left.

The coaxial cables from the matching networks terminated in this turret head in the central console.

Central console with the coaxial turret access panel secured.

Point to point operators at work.  Note the National receiver in the console above the counter.

These magnificant receivers listened to the world.  The city names above the receivers read, from left to right, Tokyo, Manila, Papeete, Honolulu, Tokyo.  MRHS member Richard Dillman remembers listening to these receivers when he visited the point to point receiving room in 1972.  The only item remaining that is seen in this view is the small roll around cart at the extreme left.

Panalyzer on central panel for oeration from Collins receiver (1960).

Here we see Steve Bowers,  (SB) on the left.  To the right is Joy E. Kinney, point to point technician, ex-KPH marine Telex operator, ex Radio Telephone Operator at RMCA WGK St.Louis, (JK). SB talking to JK at the point to point receiving station operations room at Point Reyes RS (the wire line designation for the station) on the second floor. JK and WGK's manager, Ed Fleming, transferred to RS when RCA closed WGK. Ed took the single RS tech opening, and Joy Kinney took an open KPH telex operator position. He later transferred to RS as a Receiving Tech when a position opened. When RS closed, Joy transferred to Central Telegraph Office in San Francisco as an Operating Tech. He still lives in Inverness Park and is well into his 80s.

This is a former window in the former battery room on the first floor in the process of being converted into the input port for antenna leads for the point to point service and KPH.

Shelves were built into the former window to house matching networks to transfer from the 4-wire antenna feed lines to coaxial cable.

Two shelves under construction. These shelves and the remains of the matching network remain in the former window where they were installed. Some of the matching networks will be restored to accept the recently restored 4-wire antenna leads (see the Antenna Maintenance section of this Web site for details).

This rare photo shows the scanner, a point to point receiver that was modified to mechanically scan the marine calling bands for the KPH operators on the floor below.  This setup scanned the 6, 8. 12 16 and 22Mc marine bands.

The control for the scanner in the KPH operating room is the panel to the left in this photo.  Operators had to manually hit a switch to stop the scan when a ship was heard calling.

Receivers for Honolulu, Melbourne and Tokyo.

Tokyo SSB-R3 receiver before before conversion for multicoupler use (1960)

Tone sets for keying the lines to the Central Radio Office in San Francisco.  The same model tone sets are in use today for keying the KSM transmitters in Bolinas.

RCA "H" sets on Bolinas were first used for point to point service.  Later they were used for SITOR marine service but they retained their original Dymo labels showing their point to point heritage.  These transmitters remain at Bolinas today.  Transmitter 341H was used on the Manila circuit.

RCA "L" sets were also used in the point to point service before being converted to CW use in the marine service.  Transmitter 305L was used on the circuit to Japan.  This transmitter has been restored and is now in service for KSM.

Transmitter 355H was used on the circuit to Hong Kong.

Transmitter 342H was used on the circuit to Sydney.