The video clip on our website about “the multiple antenna” is, unfortunately, only available in Swedish language.
Here’s a link to information in English about the antenna:
- Det här svaret redigerades 3 veckor, 4 dagar sedan av AlexanderSAQ.
Thanks for your message.
The air time for the Old Lady is very limited and has, so far, been dedicated to manual morse code transmissions.
It is certainly an interesting idea to combine more modern transmission technology with the over 90 year old transmitter.
We will give this a thought.
Fredrik / AlexanderSAQ
We cannot hear any sound from the transmitter set that can be connected to the keying. The transmitter set is equipped with two Bartlett Hayward flexible couplings between drive motor/gearbox and gearbox/high frequency generator. According to the RCA description of the transmitter, a special lubricant is needed to these couplings ”to absorb the chock in telegraph service”.
However, the keying is easily heard in the transmitter hall, as four huge relay-switches are operating for the speed compensation. Moreover, these relay-switches are cooled with compressed air in order to blow out arcs and cool the contact surfaces. The sound from the cooling air is very aggressive and varies with the keying, so use of ear protections is recommended.
Ola Hernvall / AlexanderSAQ
Thanks for the question.
No, the alternator load is not kept constant, the load variations are handled by the power network.
In order to keep the frequency constant at keying, additional torque is given by the drive motor at key-down to match the increased power to the antenna. The drive motor is an induction motor. The supply lines to the motor are equipped by transductors, i.e. choke coils with variable inductance, so the voltage to the drive motor can be adjusted between 1500 and 2300 V. The rotor winding of the drive motor is connected to variable liquid resistors, so the rotor resistance can be varied over a wide range. At key-down the inductance of the transductors is reduced and also the rotor resistance is reduced, both measures contributing to increased torque. The additional torque can easily be adjusted by the liquid resistors to match the increased load. A German radio amateur has analyzed the frequency variation at keying and found it to be within +- 10 Hz.
Ola Hernvall /AlexanderSAQ
Yes, this is correct. Unfortunately, on this year ‘s Alexanderson Day, we are unable to air any transmission, due to maintenance. There will be start-ups of the Alexanderson alternator which can be monitored live on our YouTube channel. See more information on http://www.alexander.n.se
We are looking forward to hearing your stories, how you spent Christmas Eve morning, listening to SAQ.
Please write a short story to email@example.com and let us know how it was.
Bonus for attached pictures 😉
//Fredrik – AlexanderSAQ
P.S. Don’t forget to see the live video stream of the transmisson on http://www.alexander.n.se
We are happy to hear that you will come and visit the World Heritage Grimeton Radio Station this summer.
A fantastic site to visit. Our summer transmission schedule, looks like this:
– July 3rd (Sunday): Alexanderson Day. A full day event (detailed schedule will be posted on our web site about 4 weeks prior to the event) with many activities in and around the station. Display of the Alexanderson alternator by people who worked at the station when it was in operation. There will also be two occations (morning & afternoon) of startup and transmission of a message over the antenna that day. A great event!
Thanks for the nice tip – this is a great idea!
However we do not always know the exact date and time for the next transmission until shortly before the planned date, due to the fact that we don’t have regular access to the antenna. Access is granted but never guaranteed only weeks before a planned transmission.
But we would like to improve our communication with all listeners, so a count down clock on our website some weeks before a planned transmission is definitely something we will try!
Yes, today we got access to the antenna and started the transmitter at around 14:00 UTC for some testing to make sure everything is working OK for tomorrow.
The test was successful so everything is looking good for tomorrow’s transmission.
We are exited to hear about your efforts to receive SAQ far away in California and we will do our very best to get the signals over to you.
Don’t miss the live video broadcast of the SAQ transmission, here on alexander.n.se.
The Alexanderson alternator is driven by a 600 horse power asynchronous two phase 2300V electric motor, driving the high frequency generator via a gear box. The transmitting frequency is in direct proportion to the speed of the motor. One of the great challenges with the SAQ transmitter is to maintain the motor speed at a constant rate, both when the transmitter is idling (Morse key is up) and when it is transmitting (Morse key is pressed down). This is done by an automated control system, however at start-up it needs “tuning assistance” to find the right frequency. After the initial tuning of the transmitter, we normally can keep the frequency between 17190 and 17210 Hz. On the electric motor, with a speed of 711,3 revolutions per minute, this represents a maximum deviation of a single revolution per minute between idle running and full load.
Fredrik / AlexanderSAQ
(thanks to Ola Hernvall for technical assistance)
Moved from comments: Radu / YO8SXX
YO8SXX – amateur radio qth SUCEAVA-ROMANIA, loc. KN37CQ
Frequency: 17,2 KHz
UTC: start time 10:00, end time 10:09
CALL: SAQ Grimeton Suedia
Signal report: 579 / 599, slight QSB, loud QRN from artificial source
vvv vvv vvv de saq saq saq……
cq cq cq de saq saq saq
this is grimeton radio/saq in a transmission on united nations day using the alexanderson 200 kw alternator on 17.2 khz ; the message is written by paskberg ii paskberg school in varberg . =
; understand the rep(?)ugees situation . not their choice , not their fault . refugees are an asset . refugees are also human beings . treat the refugees the way you want to be treated . all countries must help . war separates families . fight war , g ii not refugees . fight terrorism . learn to live with other cultures . eu (sn) everyone has the same value . help out , next time it could be you . =
signed : world heritage grimeton and the alexander-grimeton veteranradios vaenner association a^r =
info : we do not require any qsl reports on this transmission =
de saq saq saq s^k
receive and written by: Radu Chisalita/YO8SXX
– This report includes attached audio files containing the recording of parts of the issue and the whole final message.
– Receiving equipment: VLF converter 10-200 KHz to 10,01-10,2 MHz, yaesu FT1000 MP transceiver, inverted V antenna for 80 m amateur band, audio interface for PC recording.
This Report and attached audio files was sent to SAQ Grimeton Suedia
Moved from comments: OE3FFC, Franz
Your fine transmission on the SAQ-UN-Day i must listen on web-sdr uni twenty, because i had big QRM/QRN from my neighbor. Sri. The sigs during the whole transmitting-time were fine with S 7.
So i´m looking forward to your next transmission with the “old boy” with my new homebrew rig.
Many thanks for all,
de — . …– ..-. ..-. -.-. :))
Moved from comments: G3JNB
Very heavy static S9+60 covered most of the transmission this time. 100ft LW, VLF converter to FT2000.
Disappointing but glad the Old Lady did her stuff again.
73 Victor G3JNB>
Moved from comments: OK1DSO , JARDA
SAQ-UN Day Transmission very very strong S / N + 30 db, Receiving Mini Whip. PC and saqrx_exe, near Prague airport
Moved from comments: Erik PE1NOJ
Strong signal (RST 578)
Eddystone VLF receiver and Mini Whip
Thank you Lars
Moved from comments: RA4HGN
Heard SAQ RST 579. My QTH Samara, LOC: LO53CF, QRB 2390 km, Setup:
1. ANT – long wire 80 m
2. RX – sound card PC
3. Soft – GNU Radio
Moved from comments: Bert, SM1CJV
Heard the Old Lady with +28db over noiselevel,RX computer+soundcard,antenna half Square 10Mhz.
73 de SM1CJV/Bert
Moved from comments: Stig Linnarud, SM4EFQ
Har idag emottagit er sändning på 17.2 KHz ,
RST 579, ngt QRM men annars stabil signal.
TACKAR ! Vi höres. 73 Stig.
Moved from comments: DF7DJ, Bert
Nice transsmission today. Copied very good in the near of Dormund with homemade converter and aktive antenna.
Moved from comments: Hajo
Very good and stabil signals and
a very good message to all people of the whole world.
Thank you dear Lars!
The simple answer to your question is that we have no modulator, it is pure CW we are sending out. There is however no prefect square wave but it has a short rise- and decay time (about 12 ms).
However, Arne Siko here at the Alexander association had a data simulation made on a rough theoretical model of the antenna, and in the curves of that simulation one can discern an overlay that would be perceived as a 1100 Hz tone. We have never thought of this, as we see an overshoot in the amplitude at approximately 15 ms, that we thought little of, but not found any explanation. All this can be seen on the attached report.
/Fredrik Wiklund @AlexanderSAQ with help from Ola Hernvall
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
Of course its on SATURDAY December 24th and not Thursday…thanks for noticing. 🙂
//Fredrik – AlexanderSAQ
Tests were done today Tuesday Dec 20th at around 10 UTC, see link below.
Next test will be on Friday Dec 23rd at around 09.00 UTC.
Looking forward to hearing from you all on Christmas Eve.
//Fredrik – AlexanderSAQ