Mixed thoughts of OH2LAK in the ham radio world - Hajatelmia radioamatöörimaailmasta

New remote station ready for use!

2011-11-25T02:05:00.001+02:00

Again a very long quiet period here but no worries, lots have been happening though I've felt there's really no time for anything. One very important thing has gained some attention and leaped a major step ahead before winter, that is the remote operations station on top of the tall house of the housing company where we used to live (that's news also since last writing, we've sold our flat and bought a house! :)

Rotatable VHF-UHF antenna setup of the new remote controlled station

The VHF-UHF rotatable antenna array consists of a Tonna heavy-duty 9-element yagi for 144 MHz, a Tonna 21-element yagi for 432 MHz, Tonna 35-element yagi for 1296 MHz and a Aerial SBFA antenna modified to 2320 MHz. On very top of the tower there is a Diamond VX-4000 triband (144, 432 and 1296 MHz) vertical antenna.

The antenna setup has now been tested for real at least on ä144 and 432 MHz, as there was extremely good tropo conditions over the sea few weeks ago, and I operated very good contacts to the baltic countries, Czech republic, Denmark and Sweden with the new setup and I was extremely happy finally to take part to the sudden conditions enhancements.

I'm gathering a info web of the remote controlled station and I promise to publish more data and pictures of how everything is made. I might say it is quite handsom setup :)

There's also the stationary tower up at the roof which carries big wheel omni antennas for 144 and 432 MHz, 1296 MHz versio of the 'big' wheel is still unfinished as it requires some kind of radome, a discone for all-band monitoring and few microwave link antennas to connect Espoonlahti water tank, Juhanila TSF site and our new house to the network.

Stationary tower up at the roof with general monitoring antennas
and microwave antennas for internet connections

Remote switching cabinet

The actual radio hardware inside the elevator room has two cabinets, one for cable intake & shielding and the other is actually the radio cabinet. The upped cabinet has the coaxial cables from the antennas termnated to a lightning protector block (hopefully to protect radios at the cable end!) Next to the Yaesu G-1000C rotator is the Microbit Webswitch for remote antenna rotator setup an relay control. Plan is to make the radio equipment power supply to be remote controlled to wake up the station when needed.

The first phase of the remote operated equipment;

Icom IC-706 mk2 G for 144 and 432 MHz operations
Icom IC-R7100 + SDR-IQ
Icom PCR-1000 receiver
Funcubedongle Pro
PC running Windows XP to control the SDR's and to perform other tasks.

I'm looking forward to replacing the IC-706 with Kenwood TS-2000 which I have in storage, but there are some restrictions how it should be used etc., the mobile control panel is a bit too small for full-feature HF+VHF+UHF flagship to operate.

Enroute to Dayton Hamvention!

2011-05-18T00:36:00.001+03:00

We are on our way to Dayton Hamvention with Hessu OH7LZB, writing this offline passing Greenland below us currently. Travelling there will use the well-tested scheme, so first fly to Dallas and then make a roadtrip to Dayton.. We actually fly via Chicago which is quite near to Dayton but going from there directly would make us miss a lot as the roadtrip is actually very fun, it's not just a thousand miles of road. I'm also eagerly waiting to see Rich and Cindy who kindly hosts us at their house in Dallas for few nights prior and after the roadtrip. It's been eight years from the last trip so we have a lot to catch up :)

We met my friend Yevgeny UA3AMH at Helsinki airport and found out he is on his way to Dayton too by the same flight as we are. Yevgeny goes to Dayton to promote his business Radiall antennas and duplexers.

I'm equipped with digital gear, both D-STAR and P25 and hope to see what are the latest inventions in the digital business. It was Hamvention which got me into P25 last time so it might be so again that this time some new technology will bite me, MotoTRBO maybe :)

We are most propably trackable during the roadtrip as OH7LZB-9 at http://aprs.fi/oh7lzb-9

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23cm D-STAR DV/DD repeater re-building moves on

2011-03-10T01:10:00.000+02:00

I did some hard work with the 23cm DV/DD radio units yesterday at Kauniainen Radio Club where I participated the weekly NAC contest by yelling comments to the radio shack from the workshop :)

All three radio modules have now decent antenna connectors (SMA) and the previously loosely wired service (USB) interface and the control interface are now wired to a neat D9 connector. The DD transceiver unit had both TX and RX control lines wired out so I needed to go for a D15 connector. I actually thought using a D15 also for the DV transmitter and receiver units, it would give free pins to wire RSSI, PTT, discriminator output etc. to use the modules for analog FM also. I might do that if I just find information about the required lines!

I was really surprised about the lossy and very low quality coaxial cable which was used in the original setup. The cable was not long but the connection to the chassis N-connector was quite HF-style I must admit. Now there's a SMA connector directly on the chassis which I consired well usable. Below is a close-up photo of the antenna connector revealing the details of such.

New SMA antenna connector replacing the coax pigtail

Project still goes on, next step is to start making new cables between the radio modules and the integrated controller.

POCSAG project - simulcasting

2011-02-28T13:40:00.000+02:00

One key element in paging is that it should cover a great geographical area with simultaneous transmission so that transmitters won't block or cancel each other. This technique was in use in the commercial paging network where some of the equipment used in our system originate, but we were dumb enough to discard all the material, equipment or even knowledge available when we got the transmitters. We were just looking at great PA's for 144 MHz, not actually paging transmitters where we ended up using them after a decade :)

The simulcasting technology is known and we know how we should do it, but as the infrastructure design differs quite much from the original network which was apparently synchronous till certain level, we need to do transmitter synchronizing differently. To enable simulcast, ie. multiple transmitters transmitting simultaneously on the same frequency, we need to achieve synchronization between the transmitters. Again, Hessu OH7LZB has done great job programming a PLL to the Arduino POCSAG encoder interfacing the actual POCSAG transceiver to the host controller computer. The PLL will lock to the master transmitter's special preamble sequence to achieve phase lock with it and then send out the messages in synchronous manner. This design is planned geocraphically so that there is a master transmitter in the middle, surrounded by slave transmitters.

Last week at Kauniainen Radio Club weekly club meeting, the PLL was tested initially and results were promising, the PLL locked to the test transmitter as expected.

Operating ham radio remotely

2011-02-12T00:43:00.000+02:00

One of my long-time interrests has been remote controlling ham radio equipment remotely, and I've been doing a lot of research on that side while helping Martti OH2BH with hes project of operating the contest station in Pusula from home in Espoo. The project has lasted over ten years and several different approaches to remote control has been crawled through.

Few years back, reading the swedish QTC magazine I found an article (or an advertisement) about new innovation, self-contained devices to be placed to control location and the remote radio location, which then would stretch the audio paths, PTT/CW signalling and control head data over IP network. I immediately ordered a pair of these RemoteRig boxes to play with. When they arrived, I was very convinced that they were the ultimate solution for Martti's remote.

CCF / OHDXF had a cruise meeting in January 2011, where I held a presentation about Martti's remote project. RemoteRig devices were there and Mike SM20, the author for the Remoterig devices held also a presentation about the technology and innovation of the RemoteRig devices. RemoteRig devices were demonstrated controlling a remote Yaesu FT-DX5000 at Arcala OH8X superstation with a local Yaesu FT-DX5000. Ultimate innovation by RemoteRig is that two Yaesu radio's can be remoted so that the control radio actually controls the remote radio by every knob and button, and remote S-meter and frequency/function display is showed in the local radio's display. Very cool!

Yours trulu here giving the speech about Martti's remote station. The presentation is downloadable here. Below is a short video from the meeting, Martti operating OH8X remotely (docked to Stockholm harbour)

And some D-STAR stuff again!

2011-02-10T00:39:00.000+02:00

A good time ago I received a Icom ID-RP1D/VS package from Jim N5MIJ to play with, and I have had it in my lab for a good time set up for some future interrest. Recently, a bunch of Icom ID-1 23cm D-STAR radios were offered for sale for a reasonable price, and I convinced fellow D-STAR entusiasts here that we need some radios as we do have a repeater. Only issue was to find a proper location for the repeater. The first generation repeater stuff is not packaged so that they would suffer in an outdoor cabined, although they are packed in a weather-proof looking chassis.

We took the radio's off the chassis to inspect how to re-build the setup so that we could fit everything important in to a (really) weatherproof casing and locate the repeater system to a high tower downtown Helsinki.

Finally I managed to start the recabling work on the radio units of the 23cm DV repeater (two boxes, TX and RX) and the 23cm DD data access point.

Here's the 23cm DV repeater TX unit with new SMA antenna connector in place, replacing the lossy pigtail cable which originally fed the N-connector on the chassis. Also the service connector cables and Control I/O cables are now terminated to a D9 connector, much easier for maintenance and cabling in the cabinet.

More details on this work will follow as it moves on. Next job is to modify the DV RX unit and DD accesspoint units accordingly and start planning how to fit them to the cabinet.

Quiet...

2011-02-10T00:29:00.001+02:00

It's been quiet here. I haven't died or vanished :) I've just had too much to do and not had any interresting to write about. That might be false and I'm just lazy as lots of things have happened since may when I last reported our trip to the Nordic VHF-meeting in Denmark. The trip went well, as usual I took a lot of pictures;

http://gallery.lakki.iki.fi/Nordic_VUSHF_meeting_2010_Denmark

Over the summer there was also the BIG event in Friedrichshafen, where from I planned to write something also but failed on that too. Sorry, as I had a great time and propably would have had something interresting to tell about the latest findings in the amateur world.

However, I took a lot ot pictures there also :)

http://gallery.lakki.iki.fi/Ham_Radio_Friedrichshafen_2010

The finnish annual meeting was held in June. It was very hot and we had a great meeting. I was not able to attend the meeting fully, but I visited few times. First time was to build up the temporary repeaters for the meeting and second time was to give a speech about them :) Setup being temporary is quite massive, as you can see!

Here's the setup:

2m / 70cm / 23cm FM repeaters controlled by TheLinkBox linux repeater controller. All repeaters were linked to the national IP radio network R.Net. That time, R.Net had the following coverage with 7 linked repeaters. Currently there's even few more active repeaters in the west coast, and more is coming

Later in the autumn, I visited the RSGB National Hamfest near Lincoln. It was truly an interresting trip. I flew to Manchester, rented a car and drove about 150 km to Lincoln in the nighttime to get to my guesthouse. First time ever in a car with right-side steering!

So there I was. At the wrong side of the car, at the wrong side of the road, and it was dark. I managed to reach my destination, an excellent Bed-And-Breakfast house only ten minutes drive from the showground. I highly recommend The Gables Guesthouse if you happen to be around. Excellent and kind owners ready to help with even strange questions (You wouldn't have a spare UK mains plug? :) ), nice rooms and very good breakfast.

And of course, some pictures from the trip;

http://gallery.lakki.iki.fi/RSGB_National_Hamfest_2010

First day at the VUSHF-meeting, sunshine and pouring rain

2010-05-29T02:21:00.001+03:00

Well, we arrived to the meeting place at the picturesque Island of Møn. During the day before arriving to the meeting we had travelled from Gremersdorf in Germany via Puttgarden-Rødby ferry to Denmark, and searched for few vital things en-route to the meeting; Grill coal and cash.

First things first, I opened the fleamarket from the trunk of my car even before I had laid suitcases to the sleeping quarters :) Shortly it started to really pour rain, it was so good that we had the marquee with us!

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Enroute to the Nordic VHF-UHF-SHF-meeting in Denmark!

2010-05-28T01:05:00.000+03:00

It's time again for the annual Nordic VHF-UHF-SHF-meeting, organized this year in Denmark by EDR. We took this year a ferry to Germany instead of driving through Sweden. The ferry trip was quite fantastic, very different from the ferry trips between Finland and Sweden added with the drive-through of Sweden, which we have done *many* times. Finnlines runs brand new Star-class cargo/passenger vessels between Helsinki and Travemunde. They can take up to 500 passengers in addition to the huge amount of cargo (containers and trucks etc)

We just arrived to our overnight location in Gremersdorf, Germany, and continue tomorrow to Denmark over the Puttgarden-Rödby ferry.

Our fleet consists of four cars and nine hams; Juha OH1JA, Memma OH1EG, Rami OH2LIY, Toni OH2LNM, Veli-Matti OH7VM, Marko OH8WM, Jouni OH2BZP, Tapio OH2TH and myself.

My car can be tracked over APRS using this link

200 W paging transmitter usability increased with Arduino..

2010-04-28T13:30:00.004+03:00

Hessu OH7LZB, a key player in the POCSAG project, has done again wonderful work to get the 200 W paging transmitters running. (We set the transmitters aside from the dismantling of the commercial paging network)

The paging transmitters have a controller card which we are not currently using due to lack of documentation how to interface to it. Arduino comes to rescue, and acts like a interface between the paging network client and the transmitter. See the video below!

The Arduino board sits on a interface PCB which is pressed to the controller board connector on the transmitter.

We are planning to replace the test transmitter at Haukilahti water tank with the 200 W Tecnomen Hi-Q transmitter with the Arduino interface. The following chart resembles the coverage area with the current 20 W transmitter (dark green) and the new 200 W transmitter (light green).

Service area estimate for the POCSAG pilot system

2010-04-25T01:53:00.002+03:00

I downloaded few hours ago the wonderful Radio Mobile -software which is a freeware prediction software to do coverage area plotting etc, with the assist of topographic map data available. I decided to give it a try with the POCSAG paging transmitter. Everything else I had solved out to create the map, but the manufacturer detail of 5.7 uV/m signal strengh requirement for paging reception was quite hard to punch in, in another format, of course..

The map shows quite accurately the locations as coverage area (green), where we have received paging transmissions successfully. I still propably would'nt actually trust 100% this software, as the topographic material lacks all urban buildings, houses etc. The topographic data for Finland is available only in 3 arc second resolution, which is about 100m in landscape resolution respectively..

POCSAG pilot network live and works well!

2010-04-24T14:40:00.003+03:00

The first transmitter of our POCSAG network has been installed to a "real" location on top of a local water tower where we have VHF antennas already installed. The transmitter outputs 20 W power on 144.975 MHz to a half-wave dipole which is about 100 m ASL. The single site has quite significant coverage area, much wider than I expected. I did not expect the little pager to be able to receive error-free pages from over 10 km distance from the transmitter while driving in a car, with pager on my belt. Also a DX-spot was received at the OH2K clubhouse 7km from the site, which is a concrete bunker, very RF tight!

The transmitter at the site is the first proof-of-concept transmitter build for testing (Motorola GM340), with breadboard POCSAG encoder. Lately we have also gained more information about the Tecnomen Hi-Q transmitters (200 W output power) to use them for POCSAG when the network spreads out.

There has been quite good interrest about the project over here in Finland but also from the readers of this blog. We try to document all we do as best as possible to make the work for other paging enthusiasts easy!

The pilot network delivers currently personal messages and few group messages for the subscribers. Currently the group messages are for DX-cluster spots which are fetch automatically from the DX-Cluster network; HF spots regarding Finland, 6m/4m spots regarding Finland and 2m and up spots regarding Finland. SAR-people (Search and Rescue, VAPEPA in finnish) have also impressed their interrest for group messaging for alerting and information delivery for their purposes. RATS has a SAM magnetometer online, we have also discussed about possibility to alert developing aurora conditions using the data from it.

Individual subscriber messages can be currently sent via APRS network as APRS messages to destination callsigns with a specific SSID, who are registered to the POCSAG network. In future, there are maybe ways to send individual messages using SMS or web-based forms.

The infrastructure has been designed and coded by Hessu OH7LZB, and the design seems to be quite robust. The client code (which resides at the computer at the transmitter) includes also a transmitter beacon function, which sends a specific group message (RIC 0011111) stating the station callsign (for identification) and the network status to notify the status of connectivity to the server. This group transmission occurring every five minutes is also a good method of evaluating the coverage area.

Parallel work is starting to design and build the tools needed for network and subscriber management. Currently Hessu touches the database quite directly to do things. Thoughts for subscriber management have included web-base tool where subscribers can add their RIC codes to the system and manage subscriptions to individual services, and propably even group services, if we get information about the OTA features in the pagers. OTA stands for Over-The-Air reprogramming, with which it would be possible to add and remove group affiliations from the terminals (pagers) and manage other settings amongst too. We have requested information about OTA from the pager supplier, waiting eagerly for answers!

73 for now!

D-STAR update: Our 2m repeater OH2RCH C gets new firmware

2010-04-02T23:49:00.003+03:00

I'm not sure is this news of any kind as it does not provide new functionalities to the repeater, it is just inline to keep up with Satoshi's code version. The repeater had been running v5.48L code for some time now, and I had upgraded all my other v5 chips to v6 as Satoshi provided a free upgrade for them, and decided to upgrade the repeater firmware as well when David G4ULF confirmed that hes code works OK with Satoshi v6 too.

The picture shows the Satoshi Node Adapter board and the actual repeater radio, Nokia BC58 without the 50W PA board.
I had to lift up the Satoshi board for minor fixes needed by the v6 code. The board is a very early version of the Node Adapter PCB, also featuring several modifications to run the v5 code too.The repeater runs surprisingly good from its site, running only 20 W power out.

OH2RCH C is the first full D-STAR compliant repeater in Finland. The transceiver is a modified Nokia BC58 repeater radio, interfaced to a Satoshi Node Adapter board.

The D-STAR repeater controller and gateway functions are provided by linux sofware written by David Lake G4ULF. David has done great job enabling these non-Icom repeaters with all D-STAR features available. The repeater is registered to the real D-STAR G2 network via the K5TIT trust. OH2RCH C features full G2 routing capabilities, DPLUS functionalities and DStarMonitor is running for location advertizing.

Currently the software supports only single radio port per site but now as the Satoshi firmware supports updating the USB product code, identifying multiple radio ports by USB product code is possible. David told however that support for multiple ports is not propably introduced yet in the near future

POCSAG project presented to the public at RATS technics day

2010-03-22T13:05:00.000+02:00

The POCSAG project has now been officially published and demonstrated to the public for the first time, at the RATS technics day held few weeks back (sorry, I am a lazy blogger :)

Initial interrest to the project was surprisingly strong, which I personally am really happy about. That could mean also there are lots of potential contributors to the project, either assisting building the network or providing sites for the transmitters. Hessu OH7LZB had done good work to present the infrastructure he designed for the POCSAG project, and there was the proto TX site feeding messages from APRS network and DX cluster via this infrastructure.

That is Hessu OH7LZB himself at the board where we presented the project. To show off a little, we brought also the Tecnomen Hi-Q POCSAG transmitter, which we have a suitable pile storaged away, acquired when the commercial national paging network Kaukohaku was decomissioned.

The Hi-Q can push out 200W power on 144 MHz, which should give quite good coverage and therefore no need for too many transmitters forexample to the capital area.

Project moves onward slowly, currently we are looking for a pager model to fulfill the needs for the "customers" for this network. Fortunately the world is not yet completely pagerless, and we found suitable pager dealers from the USA. I ordered a test batch of pagers from a dealer saying that they can provide the predicted amount of pagers this network is going to need when in full run someday. More about the new pagers when they arrive!

Network infrastructure prototype for POCSAG network ready for testing!

2010-03-16T14:18:00.001+02:00

Hessu OH7LZB was busy over the weekend and the result was the first working revision of the server and client software components to drive the POCSAG network. There are also integrations to DX-cluster network to feed dx-spots to the pagers and APRS-IS integration for APRS messaging.

Hessu has an article of the setup in his blog.

OH7LZB contributes to the POCSAG project

2010-03-13T01:23:00.000+02:00

Great news everyone! Hessu OH7LZB, the author of APRS.fi, joins the POCSAG project by developing and producing the first version of the client-server infrastructure for the paging network, so we have something working to show at the RATS meeting next weekend. As I write this, Hessu's system is feeding the test transmitter DX-spots in quite constant stream..

Great job Hessu, thank you very much for your contribution!

OH8HQL contributes to the POCSAG project

2010-03-10T17:20:00.001+02:00

Jarkko OH8HQL from OH8TA radio club has contributed this SMD version of the AVR POCSAG encoder, very fine job indeed! We are looking into the options of making a small batch of these in some cheap PCB factory.

Click the image to inspect it full-size!

Great job Jarkko!

First POCSAG pages sent and received OK!

2010-03-10T11:25:00.001+02:00

The test setup for POCSAG paging on 144.975 MHz is working and the first messages have been sent and received successfully! This Proof Of Concept-setup will be on display in few weeks at the RATS technics-meeting held in Espoo. We will try to automate something to be sent to the few test pagers we have.

Next thing to do is to design the infrastructure for the paging network and investigate how to use the real paging transmitters left behind from the commercial network in this system. We can, of course, use the transmitters as just transmitters and create the modulation using the AVR POCSAG encoder, but it would be interresting to be able to use the internal modulator and POCSAG encoder of the transmitters. I'll keep this issue posted too.

The YouTube video above shows the first tests with the encoder and few test pagers, and my image gallery has some more pictures of the project

So what if paging is so last decade. This is fun!

POCSAG paging project moves forward

2010-02-26T12:04:00.000+02:00

There has been a long-going project to do POCSAG paging on amateur bands. Some time ago at Kauniainen Radio Club we talked about that again and decided to give it a try, as we coul determine a handful of services for such system. DX spots could be delivered to either group message or individual customized spots, APRS messages could be delivered to pagers (this is also being processed and projected by Bob Bruniga), tropo condition alerts, club notifications locally etc.

I have purchased a small batch of programmable pagers some years ago and it was time to dig them out, we had started to play with a AVR POCSAG encoder by N2RVQ, but had some trouble compiling the code to a compatible ATTINY-processor. Last night we eventually got things running after finding out that some pull-up resistors were missing from the proto board and the main loop of the code did not run because of that...

The picture shows the test TX (Motorola GM340) and the AVR proto board which houses the AVR processor to send out the POCSAG page controlled from a RS232-line.

I hope to update you with a working page video or other proof of functionality next week!

Welcome, the few readers :)

2010-02-19T11:48:00.000+02:00

Decided to start a blog, though I do not generally like them as I do not want to just write what I have been doing or share my emotions about global or local issues, as I do not feel my opinion is that important that it should be readable worldwide...

This blog should and shall be about the technical journey through amateur radio technology and my personal passion for digital communications, remote operations and other interresting 'ham radio stuff'. I hope that I can publish my first technical blog article soon, I have lots of projects in pockets getting ready.. D-STAR, P25, POCSAG on 2m, remote ops of HF and VHF/UHF radios, and maybe even little microcontroller stuff, which I do not understand a single bit (hah!) yet..

Few ham radio related trips coming up during the spring and summer, more about them later.

73 & R2D2 to you all.