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  • in reply to: SAQ 16 november 2022 #9788
    AlexanderSAQ
    Keymaster

    Dear Jochen,
    We made some tests yesterday and everything went well.
    Information about today’s schedule you will find here:

    SAQ scheduled to air on November 16th, 2022.

    Fredrik/AlexanderSAQ

    in reply to: SAQ 16 november 2022 #9787
    AlexanderSAQ
    Keymaster

    Dear Jochen,
    We made some tests yesterday and everything went well.
    Information about today’s schedule you will find here:

    SAQ scheduled to air on November 16th, 2022.

    Fredrik/AlexanderSAQ

    in reply to: Supporting Masts Ground Grid Connection #9769
    AlexanderSAQ
    Keymaster

    Dear Marcus,
    Here are some details of the antenna:

    The top lines
    The antenna current is distributed over the antenna via eight top lines. These go from the tuning coil at the station building up to the cross arm of the first tower, then under the cross arms of the other towers, and finally down to the tuning coil at the last tower. The material in the top lines is phosphor bronze, which is sufficiently tensile to withstand spans as long as 380 meters. The top lines are suspended in 2.9 m long insulators.
    (Originally there were twelve top lines. These were equipped with so-called break couplings, which had a dual purpose. They would break and let the lines fall down in the event of a large ice load or strong winds, partly to protect the lines from breakage, but also to protect the towers from extreme loads. However, the breakage couplings broke awkwardly often, and after a major cable race in the late 1960’s it was decided to remove four of the top lines, thus reducing the load on the towers so that the breakage couplings were not needed to protect them, and the breakage couplings could be replaced with fixed suspension. the problems with the top lines have been greatly reduced since then.)

    Radiant parts of the antenna
    Only vertical polarization works for long-distance connections. Therefore, useful radiation occurs only from elements that have a vertical component. From each of the intermediate towers, a conductor goes down to the ground almost vertically, and it is from these conductors that the radio radiation takes place. In addition, the ups and downs at the end towers are radiating. Between the towers, the top lines have no radiant function. On the other hand, the top lines act as capacitances in the oscillation circuits of the antenna.

    The oscillation circuit
    A capacitance and an inductance together form an oscillation circuit with a resonant frequency which is determined by the magnitude of the capacitance and the inductance. The capacitance in Grimeton’s antenna is formed by the top lines that make up one “plate” in the capacitance and the ground plane that make up the other “plate”. The capacitance of the antenna is about 47 nF. The inductance is mainly formed by the six tuning coils. The resonant frequency, i.e. the desired transmission frequency 17,200 Hz, is affected by adding on more or fewer turns on one or more of the tuning coils. Fine adjustment takes place with the variometer (variable inductance) inside the station building.

    Tuning coils
    The six tuning coils have a considerable format, about 1.8 m high and 2.7 m in diameter. They are set up on concrete foundations. The inductance of each coil is about 0.01 Henry.

    Ground line network
    An important part of the antenna is located below the earth’s surface. Along the entire length of the antenna, copper conductors are buried across the longitudinal direction of the antenna. These conductors reach about 250 m on each side of the antenna centerline. The distance between the copper conductors is normally about 6 m. Near the towers and the tuning coils they are denser. The copper conductors are interconnected about 100 meters from and on each side of the center line.

    Balance network
    To achieve good ground contact, each tuning coil is connected to the ground line network in 14 points. This is done via the so-called the balance network. This consists of conductors that are hung in wooden poles about 4 meters above the ground. The balance network branches out from the tuning coil to seven connection points on each side of resp. tower. The connection points are located 100 meters from the center line of the antenna and the distance between the connection points is approximately 54 meters. Thus, the ground current is evenly distributed to the ground line network along the entire length of the antenna.

    I hope this will give you an idea of how the antenna works.

    Fredrik/AlexanderSAQ

    in reply to: SAQ 16 november 2022 #9768
    AlexanderSAQ
    Keymaster

    Dear Job,
    Yes, we have finally got everything in place for a transmission on November 16th.
    Please read more here: https://alexander.n.se/saq-scheduled-to-air-on-november-16th-2022/

    Fredrik / AlexanderSAQ

    in reply to: Antenna Conductor Details #9702
    AlexanderSAQ
    Keymaster

    Dear Marcus,
    A phosphor bronze wire consists of 7 strands, each 2.5mm in diameter, twisted into a helix, forming a rope.
    The vertical radiator in tower 2-5 is made from six thinner phosphor bronze wires, see image https://commons.wikimedia.org/w/index.php?curid=1296820, separated by a metal ring, 250mm in diameter.

    Fredrik/AlexanderSAQ

    • This reply was modified 1 month, 1 week ago by AlexanderSAQ.
    in reply to: Antenna Conductor Details #9700
    AlexanderSAQ
    Keymaster

    Dear Marcus,
    The antenna top distribution net is made from 8 pcs 7×2.5mm phosphor bronze wires. The 8 wires are mounted on isolators, hanging down from the top support structure. The sag between each tower is approx. 17m, depending on the temperature.
    At each tower, there is a tuning coil, made from litz wire, 1.8m in height and 2.7m in diameter. On tower 1 and 6 the coil is located were the top network is going up/comming down. On tower 2-5 the tuning coil is connected to a near-vertical lead, connected to the top distribution net.

    Fredrik/AlexanderSAQ

    in reply to: Will there be a transmission on 24.December 2021? #9259
    AlexanderSAQ
    Keymaster

    Dear Alex,
    YES!! – we are planning for a transmission on Christmas Eve, Dec. 24th.
    A brand new post (https://alexander.n.se/saq-scheduled-for-a-transmission-on-christmas-eve-december-24th/) on our website alexander.n.se will reveal all details.
    Looking forward to your report!
    //Fredrik / AlexanderSAQ

    in reply to: SAQ transmission on UN Day Oct24th 2021 (NOT FOR QSL) #9232
    AlexanderSAQ
    Keymaster

    Hallo Hans-Peter,
    Bitte hier einen offiziellen Bericht hinterlassen:
    https://forms.gle/PiyVsFuNZY1junuk8
    MfG,
    Fredrik / AlexanderSAQ

    in reply to: SAQ transmission on July 4th 2021 (NOT FOR QSL) #9208
    AlexanderSAQ
    Keymaster

    Dear Ricardo,
    Yes, we are planning for a transmission on October 24th.
    Startup of the transmitter will begin at 16.30 CET (14.30 UTC) and a message will be sent out at 17.00 CET ( 15.00 UTC)
    The entire event can be followed live on our YouTube channel here: https://youtu.be/f6cEm9A71g8

    The text to be transmitted is not published in advance, but this year’s message is composed by the Swedish human rights lawyer and sustainability expert Ms. Parul Sharma.
    Transmitted speed is usually close to 15 WPM.
    You can read more about the entire event here: https://alexander.n.se/saq-grimeton-un-day-transmission-on-october-24th-2021/

    Best of luck!
    Regards,
    Fredrik/AlexanderSAQ

    in reply to: TX frequenciy audible #9174
    AlexanderSAQ
    Keymaster

    Dear Emil,
    That’s an interesting and exiting twist to this question.
    We have never had any visitor (old or young) telling us that they have “heard” the 17200Hz.
    One should know that the machine, when running, is creating lots of loud noice in the transmitter hall, mainly coming from the air cooling fan, used to cool and blow out any arcs on the large contactors for modulation of the carrier wave. So to pick up any high frequency sound it that environment would be rather difficult.
    One could also wonder why many visiting children, gets restless and sad during the transmitter startup. Could that be the high frequency that they are picking up?
    Most likely not. I beleive they just get bored and wants to go out and play on our new playground 😉

    Fredrik / AlexanderSAQ

    in reply to: Receiver #8993
    AlexanderSAQ
    Keymaster

    Dear Juerg,
    A receiver kit is available from the shop at World Heritage Grimeton Radio Station.
    Link: https://grimeton.org/radioaffaren-2/?lang=en
    Please write to info@grimeton.org to order one.
    Fredrik / AlexanderSAQ

    in reply to: SAQ transmission on July 4th 2021 (NOT FOR QSL) #8992
    AlexanderSAQ
    Keymaster

    Dear Mark,
    What a beautiful receiver!
    Fantastic with the “SAQ – Radio” sign, as well.
    Thanks for sharing this with us.
    Fredrik / AlexanderSAQ

    in reply to: SAQ transmission on July 4th 2021 (NOT FOR QSL) #8991
    AlexanderSAQ
    Keymaster

    Dear Whitham,
    Thanks for your feedback.
    Yes, the frequency was a little low, around 17.180 KhZ.
    We could not tune at 17.200 kHz without loosing motor power and we don’t have a clear idea of why this happened.
    Propably it is some settings in the combination of idle rotor restance / key-down resistance, and correct tuning of the automatic speed control, that are incorrect.
    We will do some more research on this after the summer break and can hopefully do some tests around the UN Day, October 24th.
    Fredrik / AlexanderSAQ

    in reply to: schematics #8937
    AlexanderSAQ
    Keymaster

    Mike,
    Sorry, but we have no updated, modern schematics to publish at the moment. An updated set may be available in a while.
    You can find the original schematic from April 1923 (large file) here:
    https://drive.google.com/file/d/0B3A7AtKeUBOqS2hoYTZyNWM2Sjg/view?usp=sharing&resourcekey=0-T5LnmxwbjqrmfFG6JK2GnA

    Regards,
    Fredrik / AlexanderSAQ

    in reply to: Transmission #8824
    AlexanderSAQ
    Keymaster

    Great to hear that you have your receiver ready.
    Due to the ongoing pandemic, there is no confirmed transmission for 2021 but we will do our best to get on air this year.
    Keep checking our website and subscribe to our newsletter to stay updated about any upcoming transmissions.
    Fredrik / AlexanderSAQ

    in reply to: Chills copying by hand SAQ’s moving message today #8228
    AlexanderSAQ
    Keymaster

    David,
    Thanks for your very nice comment. We are very happy for our successful transmissions.
    Kind regards,
    Fredrik / AlexanderSAQ

    in reply to: Antenna-direction #8220
    AlexanderSAQ
    Keymaster

    Dear Jens,
    The antenna towers are directed towards Long Island, outside New York, where the receiving station was located.
    My theory is that its because Googe Maps uses the Mercator projection type for its map images. It gives accurate ‘zoomed-in views’ but this projection also distorts a ‘zoomed-out view’, which will make it look like the antenna towers are pointing in another direction.
    Maybe there is a better explantion out there.
    Regards,
    Fredrik / AlexanderSAQ

    in reply to: SAQ Transmissions on July 5th, 2020 (NOT FOR QSL) #8140
    AlexanderSAQ
    Keymaster

    Best of luck James. Looking forward to your report.
    Fredrik / AlexanderSAQ

    in reply to: SAQ Transmissions on July 5th, 2020 (NOT FOR QSL) #8138
    AlexanderSAQ
    Keymaster

    Dear Mark,
    Exiting to hear about your tube receiver and all luck to you today. Looking forward to receiving your report.
    Fredrik / AlexanderSAQ

    in reply to: Transdmission afternoon 30 June 2019 #7758
    AlexanderSAQ
    Keymaster

    Dear Whitham,
    Yes, all reception reports from the Alexanderson Day June 30, 2019, filed to us via online form or by Email will receive a QSL.
    We are currently putting together the complete listeners reports list which will be published any soon.
    After that we will issue the QSL cards.

    Kind regards,
    Fredrik / AlexanderSAQ

    in reply to: Christmas Eve Morning Transmission 2018 #7512
    AlexanderSAQ
    Keymaster

    Dear Rob,
    I am sorry to hear that we may have missed your report.
    Did you send us an Email or did you report via bureau or by mail?
    Kind regards,
    Fredrik / AlexanderSAQ

    in reply to: Automatic keying message (aka "wheel") fpr SAQ #6904
    AlexanderSAQ
    Keymaster

    Dear Duncan,
    According to the “Manual for the telegraph co.” (“Handbok för Telegrafverket”) from 1933, they were using the 2-line Creed-system perforator and punch hole reader at Gothenburg Radio. The signal was then relayed to the Grimeton radio station over the telephone line.
    The Creed system is a further development of the original Wheatstone system.
    At the radio station, we are in the possess of a perforator and punch hole reader from those days, both seems to be for field use.

    The punch hole reader used at our start-up sequence, is a “Hell” 5-line type, of a more modern style, propably introduced when Morse code was replaced by Telex/Teletype and frequency shift. For example, the radio telegram connection between Sweden (Grimeton) and New York via Tanger, was using this 5-line system however with slightly higher speed (60 Baud) than with Telex/Teletype (50 resp. 45 Baud).

    Regards,
    Fredrik / AlexanderSAQ (with lots of assistance from Ola Hernvall)

    in reply to: Christmas Eve Morning Transmission 2018 #6902
    AlexanderSAQ
    Keymaster

    Dear Christopher,
    Sorry for my late reply.
    The small plank pieces seen on the live video stream are used to start the circulation pumps in the liquid resistors. There are two liquid resistors used as variable rotor resistance for the electric motor.

    The liquid resistors consist of about 2 m high containers, in which electrodes made from stainless steel are dipped into the liquid consisting of water and sodium carbonate. The liquid level in the containers may be varied by “sluices” controlled from the control board (you can see the operator adjuating the liquid level several times during the startup phase). This regulates the resistance between steel electrodes and thus controlled the rotor resistance. The heat generated is cooled off in the liquor through a heat exchanger for cooling station facility. Read more about this and watch video (Swedish language) here:

    The Alexanderson transmitter

    Best regards,
    Fredrik / AlexnderSAQ

    in reply to: Who is allowed to key the transmitter? #6667
    AlexanderSAQ
    Keymaster

    Dear Laurens,
    First, we are sorry for our late reply.
    Currently we have two dedicated telegraphists, keying the SAQ transmitter on transmission events.
    We schedule two annual transmissions, one on Alexanderson Day, early July, and on Christmas Eve morning.
    In between, we do not make any transmissions, other than occasional tests.

    Let’s hope you will be able to complete your build of your transmitter in time for the coming Christmas Eve transmission.

    Kind regards,
    Fredrik / AlexanderSAQ

    in reply to: Grimeton antenna details in English #6602
    AlexanderSAQ
    Keymaster

    Dear Ugo,
    Here’s a short desciption of the antenna and the ground network:
    There are 6 antenna towers, each 127 meters tall, with a total distance of about 2000m between tower no 1 and no 6. The six towers are oriented for best radiation towards New York, though, we have not seen any document that confirms this. The radiation pattern of the antenna is almost omnidirectional, with a slight increase in NW-SE direction and a slight dip in the NE direction.
    Along the entire antenna there is a 500 meter wide ground grid and the coils at the towers 2-6 are connected to the ground grid via overhead lines, 100m out from the towers, 7 connections on each side from each coil (no connection near the coils).
    At tower no 1 it is a bit different. The coil is connected to the alternator and it is the alternator that is grounded. The alternator is connected via overhead lines to the ground line in 10 points, 5 on each side. The connection points closest to the station building are roughly 100-200 meters away from the buildning so you can assume that there is no ground grid close to the station building. Instead, overhead lines have been supplemented with extra lines closest to the station, which can then be seen as an elevated ground plane that replaces the missing ground line there.

    The radiant parts of the antenna are almost vertical at towers 2-5. At towers 1 and 6, the top lines that goes up/down at about 45 degrees, is giving “useful” radiation.

    Fredrik (with assistance from Ola Hernvall) / AlexanderSAQ

Viewing 25 replies - 1 through 25 (of 58 total)