12 mars, 2023 kl. 09:04 som svar på: Question Antenna-Ammeter-Current at about 13:28 CET #10067
Sorry for late reply.
The antenna current meter, located in the upper right corner of the control panel is an important tool in the process of tuning SAQ.
The scale is between 0 – 200A, however it is logarithmic and really hard to read at 50-70A where we are today.
We always try to get as much amperage out into the antenna as possible. On World Radio Day, Feb 13th 2023 we had about 60A on the meter which is just below our target 65A.
The reasons to that could be many, weather, humidity, temperature, and of course, our own skills.
Tuning SAQ is a matter of keeping the main drive motor at a very constant speed, both at key-up and at key-down. The speed of the drive motor will directly determine the transmission frequency. There are two large liquid rheostats, filled with water and sodium carbonate, where the resistance can be adjusted by increasing or lowering the water level using a motor operated gate. The rotor of the main drive motor is wound three phase, and each lead goes to one of the liquid rheostats, to three separate copper bars, from which a set of hollow tubes, with different lengths are mounted, hanging down towards the water level. When operating the gate from the control panel, the water level increases, more tubes will come into contact with the water, and the resistance between the three rotor phases will decrease, giving the motor more torque. At key down, a second liquid rheostat will be connected in parallel with the first one, giving a good “torque boost” to the drive motor.
Another aspect of tuning SAQ is to adjust the tuning frequency of the antenna, to exactly match the alternator frequency. This is done by operating an adjustable inductor coil at key-down and observing the meter for outgoing power to the antenna. Turn the inductor coil until maximum power has been reached. Don’t forget to keep an eye on the speed of the drive motor, so that tuning is done at the correct frequency.
//Fredrik18 februari, 2023 kl. 11:58 som svar på: Could not receive at 17.3 kHz #10019
Sorry, you could not hear SAQ in WRD 2023.
We do receive positive reports from New England, this time we have a positive report from NH.
You can check out all received reports here:
Fredrik / Alexander association18 februari, 2023 kl. 07:19 som svar på: “Rectifiers” at SAQ #10018
The two DC generator sets for 125/250 V DC consist of two 125 V DC generators each and between these is an induction motor as the drive motor. These DC generators are self-magnetizing, that means they initially build up a voltage by means of remanent magnetism, and then the field winding receives its current from the armature winding. Some consumers need 125 V DC, e.g. relays for speed control and keying as well as the control motors for the antenna connecting switch and the variometer, and receives voltage from one generator. For objects that need 250 V DC, the two generators are connected in series. The magnetic amplifier, the field winding of the high frequency generator and the field windings of the 500 V DC generators use 250 V DC.
Only one of these DC generators is in operation, the other is redundancy.
The 500 V DC generator sets consist each of a 500 V DC generator powered by an induction motor. The only function of these DC power supplies is to supply control current to the four transductors that are included in the speed control and are connected in the drive motor supply lines. These DC generators receive their field current from the 250 V DC generators.
Only one of these DC generators is in operation.Only one of these DC generators is in operation, the other is redundancy.
Fredrik / Alexander association23 december, 2022 kl. 22:21 som svar på: Christmas 2022 Covid problem #9951
Please see our homepage.
Fredrik/AlexanderSAQ22 december, 2022 kl. 19:39 som svar på: Christmas 2022 Covid problem #9944
Sorry, but Covid-19 will prevent any activity on the Grimeton radio station.
It is such a great disappointment but we have no other options.
Fredrik/AlexanderSAQ16 november, 2022 kl. 10:41 som svar på: SAQ 16 november 2022 #9788
We made some tests yesterday and everything went well.
Information about today’s schedule you will find here:
Fredrik/AlexanderSAQ16 november, 2022 kl. 10:41 som svar på: SAQ 16 november 2022 #9787
We made some tests yesterday and everything went well.
Information about today’s schedule you will find here:
Fredrik/AlexanderSAQ13 november, 2022 kl. 09:04 som svar på: Supporting Masts Ground Grid Connection #9769
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.
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.
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/AlexanderSAQ13 november, 2022 kl. 09:00 som svar på: SAQ 16 november 2022 #9768
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 / AlexanderSAQ24 oktober, 2022 kl. 07:13 som svar på: Antenna Conductor Details #9702
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.
23 oktober, 2022 kl. 12:15 som svar på: Antenna Conductor Details #9700
- Det här svaret redigerades för 5 månader sedan av AlexanderSAQ.
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/AlexanderSAQ11 december, 2021 kl. 11:36 som svar på: Will there be a transmission on 24.December 2021? #9259
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 / AlexanderSAQ26 oktober, 2021 kl. 18:48 som svar på: SAQ transmission on UN Day Oct24th 2021 (NOT FOR QSL) #9232
Bitte hier einen offiziellen Bericht hinterlassen:
Fredrik / AlexanderSAQ19 oktober, 2021 kl. 08:45 som svar på: SAQ transmission on July 4th 2021 (NOT FOR QSL) #9208
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!
Fredrik/AlexanderSAQ22 september, 2021 kl. 10:34 som svar på: TX frequenciy audible #9174
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
A receiver kit is available from the shop at World Heritage Grimeton Radio Station.
Please write to email@example.com to order one.
Fredrik / AlexanderSAQ16 juli, 2021 kl. 10:25 som svar på: SAQ transmission on July 4th 2021 (NOT FOR QSL) #8992
What a beautiful receiver!
Fantastic with the “SAQ – Radio” sign, as well.
Thanks for sharing this with us.
Fredrik / AlexanderSAQ16 juli, 2021 kl. 10:22 som svar på: SAQ transmission on July 4th 2021 (NOT FOR QSL) #8991
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 / AlexanderSAQ29 juni, 2021 kl. 20:32 som svar på: schematics #8937
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:
Fredrik / AlexanderSAQ26 januari, 2021 kl. 15:38 som svar på: Transmission #8824
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 / AlexanderSAQ6 juli, 2020 kl. 12:03 som svar på: Chills copying by hand SAQ’s moving message today #8228
Thanks for your very nice comment. We are very happy for our successful transmissions.
Fredrik / AlexanderSAQ6 juli, 2020 kl. 11:52 som svar på: Antenna-direction #8220
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.
Fredrik / AlexanderSAQ5 juli, 2020 kl. 07:34 som svar på: SAQ Transmissions on July 5th, 2020 (NOT FOR QSL) #8140
Best of luck James. Looking forward to your report.
Fredrik / AlexanderSAQ5 juli, 2020 kl. 06:11 som svar på: SAQ Transmissions on July 5th, 2020 (NOT FOR QSL) #8138
Exiting to hear about your tube receiver and all luck to you today. Looking forward to receiving your report.
Fredrik / AlexanderSAQ18 juli, 2019 kl. 09:33 som svar på: Transdmission afternoon 30 June 2019 #7758
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.
Fredrik / AlexanderSAQ