sunnuntai 27. toukokuuta 2012

2012: Expreciencies and background of Remote FM-DX-Utö

UPDATE 26.8.2012: Experiencies
Here a few lines with updated info of 3 month experiencies of Utö's remote site:
The site has been working well through the summer although we still have a problem.
The only problem seems to be the high RF-level coming from the radars in the same cabin/site. This RF seems to break the USB-connection of ARS (remote controlled rotator) very easily and the driver must be re-installed very often! The chokes around the cables seems not to help.

Also there has been breaks with Elisa's 3G-service. We lost the connection to the site for one week after heavy thunderstorm and lightning on the 30.7. 2012 as Elisa 3G went down. This distant island does not have the highest priority to be fixed, of course. The thunderstrom was heavy also in the continent making problems on 3G-sites around Finland so we had to wait one week.
According to local people in the island there were one straight lightning hitting the island (making metallic sound) but luckily our site survived.

Here is a description and background of the installation of remote controlled FM-DX-station in far distant Utö island in SW Finland, 90 km SW from Turku city. The idea is to have FM-receiver in a distant island and you tune it at home. Heavy-DXing.

Everything changed in FM-DXing in 2011 by Perseus FM+, which appeared to be a very good and sensitive FM-tuner. FM-DXers around the world use conventional home-FM-receivers which are very difficult to install remote-controlled. FM-Perseus made this possible. The other positive thing in Perseus FM+ is that you can record 2 MHz bandwidht (or 1,9 MHz) at once.

I (Harri Kujala, blogger) started to plan remote controlled FM-DX-station in autumn 2011. The idea was based on my collegue-DXer's Kimmo Vuorela's experiencies on remote-controlled AM-Perseus installations in Karvia, mid-Finland. He lives in urban area in Espoo and tunes country-side AM succesfully (using many remoted longwires).
So, I and Kimmo decided to install similar system on FM to the best possible FM-QTH, Utö island. No interferencies from local transmitters. The site is located in the Utö's sea-pilot-station, beside the Utö lighthouse.
It takes 2 h by car and 4,5 h by ferry to Utö from Turku. You must also stay overnight if you go there. This means that when making installations to this kind of place, you need to have everything double-checked to avoid extra visits!
After 4-5 months of preparations and tests we were ready to go there in mid May 2012. We had 36 h time to get everything installed. All this time was needed, no breaks, no eating, just installing and testing the whole Saturday. Many key-things were still left open when arriving there, and we had many thrilling moments (about mobile internet connection, interference from 3 radars above, rotator, tower, guylines etc.).
We had pre-check visit in April but you never know...  

Here is a description of the system in Utö. Click for a better view:
Photos of installations in Utö in mid-May:


There were many questions while planning this:

- How to open computer remotedly? 
Kimmo had solved this by Nokia 3110-phone-controlled relaybox (PG-11) which is a product of Probyte Oy. With this we can control 4-6 relays to start PC, change antenna etc. With PG-11 we close or open relays by phoning to Nokia 3110-phone (very old Nokia-product and not easy find anymore) and give numeral codes. This phone opens automaticly itself after two call-tones. Then,  for example, we start computer by typing a code 321. It gives 1 sec. pulse to start-button of PC (via relay 2). So, this is like I press the start-button for 1 sec. time with my finger!
Nokia 3110 runs by prepaid SIM-card, so there are no extra costs.

- How to protect Perseus-receivers from lightning?
This is a very bad problem on FM-remote installation comparing to AM. The lightning can destroy your equipment.
We have extra relays and box to connect yagis to the ground when not in use. This might not be enough, so there is always a risk that lightning will destroy our system. We have also installed lightning protection to the mains current 220V.  Also we use GSM-controlled 220V on/off. With a simple text message we can call the site completly off the mains and call it back later.

- Can we have mobile internet-connection good enough for remote controlling PC with real-time-audio?
This is an extra-problem in a distant island. When visiting Utö-island in a pre-check we had two mobile net-sticks along. Saunalahti (Elisa) appeared to be right in Utö-island giving full 3G (8 Mb download and 3 Mb upload)!! However, there were problems on this too of which we were not aware... When Saunalahti 3G-net collapse we need to have net-stick reset. The stick will not log in automaticly when 3G comes back even after very short break. The net-stick needs then total reset because USB from PC gives power to stick altough PC is off! So, we needed to have total 220 V-reset to reset the net-stick...
This is done by GSM-controlled 220V on/off which is mentioned above.

- The best PC-remote-controll sowtware?
We use LogMeIn ( for remote controlling the computers. It gives very nice real-time-remote-DXing!! It is free to use but Pro-version costs a few euros per month giving some extra features.  LogMeIn offers also own Ignition-software to connect the remote-site faster. With free version you must use browser of course. LogMeIn is good for this.

- Audio over internet?
Another big question on the line... We are using Skype for taking receiver-audio out (LogMeIn-audio appeared to have slightly too low quality, like other similar products, too). Anway, this means that we must have line-out connected to mic-in. Works quite well with good audio. Audiostream like "internet-radio" is out of the question because these all have 20-30 s delay!! There seems not be other cheap solutions to have live audio with good quality.
- How to have IP for net-stick?
This was the biggest question for the start. Net-stick changes IP every time when you log in with it. The answer is Hamachi (LogMeIn). It gives virtual IP (or name) for the PC and it must be installed on the PC which is remoted. 
Both, net-stick and Hamachi open automaticly when PC is opening, so we can take remote control of the distant-PC with them, Hamachi and LogMeIn.
- Stable tower for antennas for extreme windy place?
The place of our antenna is certainly facing one of the heaviest wind in Finland in autumns!!!
So, the tower is guylined with rod and two steel-wires with Kimmo's excellent solutions. We hope it is enough for 25 m/s winds. The rotator Yaesu G-1000C is for heavy loads. The antennas 5-el V-yagi and 8-el H-yagi are on 3 m tower, so the wind-load is not so bad.

How to use rotator remotedly?
The answer for this came from Spain. ARS USB is designed to be connected to dozens of different rotators to use them from PC.
Like mentioned above we have problems using ARS. The ARS is connected to Yaesu-rotator-controller. However, ARS loses USB-connection to PC very easily, about after 20-30 turns the ARS-driver must be re-installed to have it back in use. The reason seems to be the high RF-level coming from the radars in the same site! We have tried chokes and metal-covers but nothing helps. However, it is useable like this. The driver re-installation takes only about 30 sec.

How to change H- and V-antennas?
There are some soft/hardwares found from internet, but we decided to change antenna by phoning antenna-relays on/off. So, when we want to change antenna-polarisation, we phone certain code to Nokia 3110 and change H/V-antennas. Perhaps we need to improve this later
altough H/V-chancing is not needed so often.

Extra harddisks?
We have 2 TB hard-disks (2 TB gives 70 h on Perseus FM+ with 2 MHz-wide recording). You must choose harddisks which are not running when PC is off. Note also that harddisks which have power voltage from USB-port do not run Perseus-files well in playback-mode! (Removing files to computer's hard-disk passes the problem).

This is working and we have made a lot of 1,9 bandwidth recordings during the summer! There will be the whole winter time to check the recordings.

1 kommentti:

  1. Huhhuh poijjat...

    Pioneerin osa on kova mutta varmaan antoisa!

    73 MJ Karperö