Historical transmitter SAQ Grimeton transmission
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- Опубліковано 4 жов 2024
- 10:20 CEST (08:20 UTC): Live video from World Heritage Grimeton Radio Station begins
10:30 CEST (08:30 UTC): Startup of the Alexanderson Alternator SAQ from 1924.
11:00 CEST (09:00 UTC): Transmission of a message from SAQ. - Наука та технологія
Greetings from Australia. Great to see this transmitter still working. Keep it up and well done to all of you.
This is the most impressing technical demonstrations I have ever seen! I visited the fantastic Grimeton last summer and seeing it in use is wonderful! Many thanks for all the impressing work keeping it alive!
Thank you for sharing and love that old machine. Please keep it running as long as possible. 73 de VE5EE
36:44 You can hear the CW transmission being received by the radio mike. Great presentation and well done to all involved for keeping this wonderful machine operating. 73's DE G8WOF QTH WIRRAL UK NEAR THE CITY OF LIVERPOOL UK. K
This transmitter is being maintained on a shoestring membership budget of only about €8,400 per year, plus anything they can raise from visitors and other supporters. not to mention a lot of volunteer work. So their call for members needs to be taken seriously, if we want to see this unique facility still operating in the coming years. Thanks to all who made this presentation and operated the station. 73 de G0MRB.
I don't know why I'm so interested in 100 years old radio stuff, but there's just something beautiful about it. Plus, your efforts of keeping it running are amazing, and makes me understand how they did it back then. If I'll visit Sweden, seeing the station in person is one of my highest rank on my priority list.
Congratulations for 100 Years (1924 - 2024) I am happy to be part of this unique event. I congratulate everyone for their effort and dedication. Thanks. Alencar - PY3CEJ
Beautiful! 4 July 2024
What a beautiful machine and amazing technology. As usual, very well explained and demonstrated! I listened through the Twente WebSDR, since my rig goes down to only 30 kHz. For future transmissions, I will build or acquire my own RX. I have applied for membership of the association. Best 73 de HA7RJA - Rob
Gratulera!! Very well received down in Granada, South of Spain.
I'm very happy and proud to be a newcomer member and Many Congrats to SAQ GRIMETON TEAM!
2 things to see in Sweden - Grimeton and the Vasa Ship.
Great transmission, thank and vy 73 I. received it only via websdr twenje. With ferrit-coil antenne or Whip and Loop I did'nt make it. Lets try later today.
Greetings from Poland SO5GB
That's cool as a fan
Brilliant. Is the Morse Key screwed to the panel the original Key.
Hello and thanks for your question.
Yes, the small morse key on the operating panel is all original 1924.
Fredrik / Alexander association
Your excellent tour did not indicate how the 50 Hz mains power was converted to DC. Was this by motor-generator, rotary converter or something else?
Thanks for your question. The 50kV AC suppy is transformed to 2.3kV and 3phases are converted to 2 phases by a Scott-connection ( en.wikipedia.org/wiki/Scott-T_transformer), which is the required supply to the main drive motor. The 2.3kV 2ph is also transformed to 440V 3ph for the supply to various drive motors in the auxilliary equipment. Here are two rotating converters that can produce 500 VDC and 125/250VDC, where the alternating current is rectified by means of a commutator, which allows direct current to be extracted from the rotor (en.wikipedia.org/wiki/Rotary_converter).
Fredrik / Alexander association
@@AlexanderSAQ Thank you. Rotary converters are fascinating pieces of equipment. They were used quite a bit in early transit systems to convert 3 phase AC to DC for third rail power.
@@AlexanderSAQ So the motor spinning the HF alternator is an AC motor? How do you adjust the speed of the drive motor to adjust the transmission frequency?
It also makes sense to me that a country like Sweden with a small population and relatively little international commercial activity could get by with one transmitting frequency. How about large generators of telegrams like the U.K. or the US?
@@Pamudder Thanks for your questions. To maintain a stable speed of the drive motor is a complex system. The voltage to the motor can be controlled between 1300 and 2300 VAC by using a Transductor, which is an adjustable choke coil, where the magnetic saturation of the metal core is adjusted with short pulses with 500VDC. The pulses are generated by the automatic speed control system which is chopping the field current to the 500VDC converter. Then the rotor of the drive motor is open in three phases. The resistance between the phases will determine the torque of the motor, and can be set using two separate liquid rheostats, one for key up and one for key down. At key down the latter is connected in parallell with the first, allowing for a lower resistance and thus more torque is applied to maintain the speed.
Sweden had a massive emigration to the US, one of six moved during the hard years in the late 1800's and early 1900's creating a great need for communication. One can also think that the fact that the inventor, Ernst Alexanderson, was Swedish, played a role in the decision.
Fredrik / Alexander association
@@AlexanderSAQ Thank you so much for the explanation.
Please, get rid of that torturous music.