Visiting Großer Feldberg repeater site near Frankfurt in Germany

Taunus Relaisgruppe is an amateur radio association operating several VHF/UHF/SHF repeaters and beacons in the Frankfurt area in Germany. The repeater locations are very optimal and provide very respective radius for the repeaters. Feldberg is 890m above sealevel and very much above surrounding terrain in general and their repeaters can be hit 100km away with an handheld radio.

TRG operates all possible modes and technologies; FM, P25, D-STAR, DMR, POCSAG, packet radio , ATV etc. Internationally they are known for the 10m repeater DF0MOT which utilizes split site technology on two separate towers on Feldberg, RX on Kleiner Feldberg and TX on Großer Feldberg.

I have operated through TRG repeaters many times during my trips to Germany, and recently during a work trip to Germany I had extra time to visit Feldberg to see how the site actually looks like. I talked with Ralf DF2RK over their DMR repeater and he was able to give me a small tour also of the repeater site up in the hill. I was quite happy for that, it's always very nice to see installations like that to get ideas for our own systems!

Großer Feldberg communications towers, amateur radio antennas on the right side tower. 10m repeater TX antenna is located in the small tower in the lowest part of the building.

As in everywhere, access to commercial sites has become more restricted and again here TRG is an great example where good relations and professional work combined provide possibility to have such of an site!

All repeaters are located up in the tower quite near the steel mast on top of the tower. Repeaters use sector antennas which provide good gain and possibility for direction-based voting if wanted (not done there)

Repeater cabinet is filled with very familiar radios, Motorola  UHF Quantar for both analog FM and P25 on 70cm. The APCO25 repeater has an second scanning receiver to create links to other P25 repeaters in the region. Using a scanning second receiver is quite ingenious method of linking P25 repeaters, which by other means would be very expensive as they were not really meant or priced for amateur community!

The D-STAR stack features an 70cm Digital Voice repeater and 23cm Digital Voice + Digital Data units. The repeaters belong to the US-Trust and run IRCddb so all the latest bells and whistles are in users disposal :)

On top of the stack there is a Motorola DR3000 70cm DMR repeater which is hooked to the worldwide DMR-MARC network.

The "indoor" antennas possible in the Feldberg-style towers are something special which we in Finland are unable to utilize as all communication towers are open-air sites and all antenna assemblies must be planned and build to be rugged and weatherproof. There are several antennas concealed in the wooden tower which is not only easy for maintenance but also enable also to use homebrew antennas as the antennas do not need to meet all possible commercial specs. There were several 23cm packet radio link antennas inside the building, and link antennas for the P25 repeater scanning receiver antennas towards the other P25 repeaters.

TRG operates also many packet radio links which operate on 23cm band. There were several link stretches looking at remote packet radio nodes.

The day we visited the site was very windy and foggy, so it was not possible to visit the top of the tower but only have a quick look through the hatch how the things look like. I was quite sure the hatch would fly away, it was *that* windy :)

The red panel antennas just above the hatch are used by amateur radio, one "level" for RX and other for combined TX. Vertical antennas shown in the right picture are for D-STAR 23cm.

There was quite significant amount of Wimax and 5GHz Wi-Fi antennas also. No wonder that some local ISP providing wireless has spotted this site to be an optimal place for long-haul trunks :)

The installallations on Großer Feldberg are very professionally done and represent amateur radio engineering very well. Thanks Ralf for showing me around!

Digital Ham Radio in Ham Radio Friedrichshafen 2012

Digital ham radio was the theme for this year's Ham Radio fair in Friedrichshafen and I must say our activity group(s) fit to that picture very well. We have been operating digital modes as the pioneers in Finland. We operate D-STAR, P25 (APCO25), DMR, TETRA and few other non-voice digital modes like POCSAG :)

For the first time Ham Radio Friedrichshafen was equipped with both P25 and DMR repeaters and a frequency for TETRA operations on 70cm band was reserved!

Homemade 70cm D-STAR repeater

Motorola Quantar 70cm P25 repeater

Icom 70cm D-STAR repeater & controller

There were substantially large crowd of people operating either D-STAR, P25 and/or DMR in the event, not that many fleamarket vendors selling that stuff unfortunately!

Jochen DL1YBL hosted a DMR meeting where the current situation of DMR in the ham radio world was updated and I had a small presentation of what we do. Presentation is available here for download.

Happy Digital guys; Niko OH2GEK & Erik OH2LAK

The OHTRBO Group was represented in Friedrichshafen by Niko OH2GEK, Janne OH2HWH, Hessu OH7LZB and Erik OH2LAK. Rich N1OZ and Darren G7LWT were hanging around with us too, both operating DMR.

Rich N1OZ and Darren G7LWT

Mr. LAM Communications,
Michael DB5KN and Hessu OH7LZB

Happy Darren G7LWT with MotoTRBO

Operating via aurora reflections on 6m

Aurora has been my favorite propagation mode always as I learned CW properly working via Aurora on 144 MHz. There's been not that much aurora conditions when I've been at the radio, and the remote operations which I do mostly these days has not changed that. Fortunately now and then I get to work some aurora contacts, have a look of one on 6m with OH2MA (Also another RemoteRig user!) with my remote setup. This also shows how well CW works with the remote system.

Updates to the remote stations

While it was good to have lots of radios at the remote site, I found the Icom IC-R7100 receiver doing nothing there as I've been generally too busy to do anything :)

Originally plan was to use the Icom IC-706MK2G as the main remote transceiver due to its superb remote touch-n-feel as the complete control head was at the remote site, just as it would control a local radio. Radio performance was not that fabulous and as I had my TS-2000X doing nothing, I decided to swap that radio to the remote site for VHF/UHF operations. In addition I got 23cm QRV too as I haven't been able to get the transverter up there either..

The current remote setup features the Kenwood TS-2000X as the main transceiver for 6m, 2m, 70cm and 23cm. (Yes, I added a 6m 3-el yagi there too!)

In addition there is the Icom PC-R1000 receiver and a Funcubedongle SDR. Down below is a Icom ID-1 1.2GHz D-STAR transceiver for 1.2GHz data transfer tests.

The PC to drive the whole setup seems to be bit too slow (and I'm running out of USB ports) so I'm in progress of upgrading the PC. Looks like I really don't need other than Windows to control all I need so I most probably will drop the original idea to run a VMWare ESXi virtual platform and on top of it both Windows and Linux virtually.



Operating the TS-2000X differs a bit from what I've been used to with the Kenwood TS-480 HF/6m remote and the Icom IC-706 as both radios have a full-size control head which can be used remotely. The Kenwood TS-2000X features only a mobile control head, which might be perfect for operating the radio mobile, but at home as the *main* control head it is bit too less. The mobile control head is the same as the APRS mobile radio TM-D700 so the touch-n-feel of a Big Rig is not there. The VFO wheel has clicks on it and its not bigger than the RIT knob on the real radio control head. I've been mostly operating the radio using the Microbit RRCMicro PC-client and Ham Radio Deluxe as the control end. It works, there's no touch-n-feel but I've got used to it and it is much less to carry along when travelling. Just a headset (which I need with my work stuff anyway) and the RRCmicro dongle which attachs to the USB port.

Here is the two remote setups running from the annual summer meeting for the Finnish Radio Amateur League SRAL. Remote operations was demonstrated but few real QSO's were made too :)

On left the Kenwood TS-480 HF/6m remote setup and on right the Kenwood TS-2000X remote with the mobile control head. Can you spot the VFO wheel? :)

New remote station ready for use!

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!

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

Published with Blogger-droid v1.6.8

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

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.