MARITIME RADIO HISTORICAL SOCIETY |
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1 April 2022
MRHS Newsletter No. 83
Dedicated to the True Believers Worldwide
Hangin' around
Teletype
Frames
Lead ins
4 wire
IMD
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In the previous week at BL this cross arm had been seen listing at 45 degrees and when a chance to investigate came on 12 February 2022, the hardware had failed and everything was hanging by the transmission line. Bob Venditti (VI) and Bill Ruck (RK) deployed some temporary repairs to get the cross arm back on the pole and additional work is needed to make it more permanent. The top of the pole is splitting and you don't bring in equipment for replacement of one item so this will have to be part of a funded project later on. In the mean time efforts will be put toward arresting the effects the elements have on the pole and hardware. This is a short pole by the way and you can see that young tree encroaching on it. |
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Before VI and RK were done for the week, the crossarm and hardware had been temporarily secured and the strain on the wires relieved. Top of the pole has been banded and fasteners need to be obtained. A possibility to prevent further splitting is to use the UPR product ( Utility Pole Repair) in the crack |
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Saturday 25 February 2022 - Hardware and bands had been installed and trying to use the same holes in the pole, any parts and pieces that remained need to be removed. These are pieces of a 5/8" bolt that VI (Bob Venditti) removed. The lump in the threaded area was a nut. Replacement parts are 5/8" HDG (Hot Dipped Galvanized) . This type of erosion is called a pencil point failure. |
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If you would like to help support this work and/or you enjoy using the KiwiSDR receivers you can use the link below to donate through PayPal or send your gift to:
MRHS
PO BOX 392
Point Reyes Station, CA 94956
The MRHS is a registered 501(c)3 non-profit organization, so your gifts are tax deductible. Our Tax ID Number is: 20-1122405.
Thank you in advance for your continued support. We are committed to using your gifts responsibly to help preserve our maritime and communications heritage!
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While doing some work at RS I passed by what I identified as a Siemens T1000 Teletype/Teleprinter sitting on a bench. The Teletype room has a whole bunch of machines, this was in the open in the shop and easy to get a picture of. Above the keyboard is the printer mechanism which is daisy wheel. On the right is the device that punches the tape with the catch bin for all the little paper dots. To the right of the keyboard is the tape reader. The tape would come out of the little slot and feed under the plate that sits above the deck. In Stand alone Telex service these also had a rotary dial and buttons in a box for operating. Page from manual is below. (RB) |
5 February 2022 On the Northeast side of RS (Point Reyes) is a set of wooden frames with remnants of 4 wire antenna leads. In the day the upkeep of both the wooden frames and the wires took a crew of people with constant attention. |
This 1959 Photo is an example of how much more equipment was in place at RS and the same can be said for BL as well. |
5 February 2022 This is the back of the building at RS where most of the antenna lead ins come into the building. Other than a handful of coax in the center of the photo, the elaborately spaced and routed twin lead left from the 4 wire days. At RS there are no transmitting antennas. This is a receive only site. Impedance of the twinlead is 200 ohms. |
This decade old picture is Paul Shinn (PS) restoring some 4 wire line. The wire is 14 gauge and not hard drawn copper. Split bolts are temporarily installed so soldering can be completed without tension interfering with the splices. Paul is using his "Big Bertha" soldering iron with Low Temp silver solder and the idea is to heat hot and fast. If you heat slow and long the wire was prone to getting brittle and breaking. The wires make a square with the corners diagonal from each other connecting together and matching the impedance of the twin lead. Bear in mind that getting power from a transmitter to an antenna might work great at one impedance and hooking a receiver to an antenna might be optimized at a different impedance |
Below is a chart for Four wire taken from the 1947 Edition of "Radio Handbook". |
International Marconi Day
Maritime Radio Historical Society’s K6KPH will be Active for International Marconi Day. K6KPH, the amateur station of the Maritime Radio Historical Society (MRHS), will be among those active on International Marconi Day (IMD), Saturday, April 23 (UTC). Organized by the Cornish Amateur Radio Club, IMD takes place each year on the weekend closest to Marconi's birthday, April 25.
K6KPH will operate on CW on 80, 40, 20, 17, and 15 meters on fixed frequencies. Since K6KPH transmits from the original Marconi site that went into service in 1914, it is a registered IMD station. K6KPH uses the original transmitters, receivers, and antennas of heritage shore station KPH. Operators at the receive station in Point Reyes, California, key the transmitters in Bolinas remotely, just as was done when KPH was in service.
The Cornish Amateur Radio Club will issue an award to stations that contact 15 officially registered IMD stations like K6KPH. KPH, KFS also will be on the air with normal operations not connected to IMD ( as it is an Amateur event). For more information go to www.radiomarine.org
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And don't miss our fabulous MRHS Swag store. Your purchases also provide some much needed income to the MRHS. To access these treasures, click on the picture of our lovely MRHS Model, Tina Shinn/TS, below! |
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When visiting KPH be sure to tune in to KWMR for
the great music,
local knowledge and,
most important, emergency information.
For more information about KWMR, and to listen to the live stream, click here.
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