Amateur Radio | Arctic Diamonds - TF4M

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Good news !

By TF4M On June 22, 2011 · Leave a Comment · In Amateur Radio

According to scientists at the National Solar Observatory (NSO) and the Air Force Research Laboratory (AFRL).

Studies indicate that the next 11-year solar sunspot cycle, Cycle 25, will be greatly reduced or may not happen at all.

“This is highly unusual and unexpected,” Dr. Frank Hill, associate director of the NSO’s Solar Synoptic Network, said of the results. “But the fact that three completely different views of the Sun point in the same direction is a powerful indicator that the sunspot cycle may be going into hibernation.”

Heavy Duty

By TF4M On June 20, 2011 · Leave a Comment · In Amateur Radio

A powerful Harris RF110-A is a recent addition to the firepower at TF4M.

The amplifier fits very neatly into a small 19″ rack which I had available and was modified for 160 Meters by TF3BM who also built the single phase 230V/4400W continous duty power supply.

Due to the noise of the cooling system, the amplifier will be installed remotely in the adjacent equipment room once I have tested it thoroughly.

The amplifier accepts 100mW input for 1000W output and is fed from the exciter through a 30dB attenuator.

It uses two 4CX1500B tubes and is simply loafing at full power. Two 8122 tubes take the 100mW and amplify this to 10W for the output tubes. The pair of 8122 tubes are capable of a kilowatt by themselves but are only running at 10W!

The manual may be found here.

Some nice photos of the amplifier may be found here.

Harris RF110-A

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K5NA @ TF4X during CQ WW160 2011

By TF4M On June 9, 2011 · 2 Comments · In Amateur Radio

CQWW2011 002 by tf4m

Perseus Server

By TF4M On June 3, 2011 · Leave a Comment · In Amateur Radio

My Perseus SDR receiver is now open to public use.

To connect use the following settings:

IP : 88.149.5.173

Port 8014

The antenna is a 20m high broadband vertical.

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Unauthenticated connections are limited to 30 minutes and can reconnect after a delay of 5 minutes.

A map of Perseus servers may be seen here.

The software may downloaded from here.

Instructions for setting up the software and router ports may be found here

Thank you for identifying when connecting to the server.

Anonymous clients may find themselves disconnected without warning.

Comments on the reception are welcome.

The Arctic Queen has arrived

By TF4M On June 2, 2011 · 1 Comment · In Amateur Radio

The Arctic Queen and the LDF7 cable salvaged from Reykjavik has arrived in her new home – rescued from a fate worse than death.

500 metres of LDF7-50A Heliax

The Arctic Queen extends 8.5 metres from the back of the trailer.

The roll contains 745 metres of control cable

The length of the trailer is 12 metres, the Arctic Queen extends out of the trailer 1 meter in the front and 8.5 metres from the back.

I am grateful to the Icelandic Road Authority for granting a special permit for this road transport.

Unloading will begin immediately.

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5BWAZ – First from Iceland

By TF4M On June 2, 2011 · 3 Comments · In Amateur Radio

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Digging for gold

By TF4M On May 28, 2011 · 1 Comment · In Amateur Radio

I am salvaging some LDF7-50 Heliax cable (1-5/8″) from the former transmitting site of TFA in the hills overlooking Reykjavik. Development of the area came to a grinding halt due to the economic collapse of the country and therefore the cable was still intact in the ground.

A 600 meter long ditch was dug with a 18 tonne wheel based excavator and the cable has been taken out of the ground.

The trench will filled back in and the site of the digging will be returned to it´s original state.

It took 5 hours by a very experienced operator to dig the trench and I estimate it will take another 5 hours to fill it in again.

Due to the sheer weight of the cable, I had to cut it into pieces in order to be able to handle it by hand. Yngvi, TF3Y passed by to check on my progress, the photos show only half the length of the ditch.

The photos are published with Yngvi´s permission – I processed them slightly to give them a HDR look.

TF4M (photo by TF3Y)

The cable will be coiled up and shipped to my station by truck – 400km by road.

This has been a lot of hard work and has been very costly, but that is the reality of digging for gold in the arctic.

The acquisition of this cable opens up the possibility of putting antennas on the peninsula called “Hyrndanes” on the other side of Otradalur river and on the other side of the road near the sea – a distance from the station of around 500 meters.

I am grateful for the cooperation I have received from the City Officials who are now in charge of this area formerly occupied by the transmitting site.

TF4M (photo by TF3Y)

My helpers on the first day of rolling up the cables: Oddur, TF3OO and his sons.

photo by TF3Y

I had the misfortune of twisting my back badly while pulling the cable out of the sand during the first day of digging – relegating me to foreman duties.

I hired a strong worker – Davíð – to assist me and I was also joined by Villi – TF3DX, Guðmundur – TF3SG and Benni – TF3CY who volunteered to assist me with the rolling up of the 500 metres of cable.

I am extremely grateful for their assistance – without their help I could not have finished the job.

I had to divide the cable into 3 rolls, each around 200 metres long and weighing more than 250kg. The rolls got larger and larger and heavier and heavier as we rolled up the cable, it turned out to be quite difficult to handle.

In addition to the cable, a 22 metre long pole weighing 2 tonnes was rescued from a fate worse than death (playground duties…) – it will now see glorious service again as an antenna support and has been named “Arctic Queen“

Around 100 metres of tower sections were also put on the trailer before I ran out of room due to height restrictions.

A special permit was obtained from the Road Authority to allow this long load to be taken by road to the West Fjords. The Arctic Queen extended 8.5 metres from the rear of the trailer.

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Uninterruptible Emergency Power Source

By TF4M On May 19, 2011 · 2 Comments · In Amateur Radio

I have installed the first of four battery banks of “Float Service” batteries normally used in uninterrruptible power systems for telephone, these batteries will keep the station QRV in the case of power failures.

The capacity of each bank of cells is 350 Ah and when finished the four banks will provide 1400 Ah at 12 Volts. Each 2V cell weighs 30kg – the total weight of the finished backup battery will be 720kg.

The existing ground-bus system at my station is used for the negative supply – the positive supply is routed through a 80A Circuit Breaker for the main supply, another 50A breaker provides power to the 12V equipment in the equipment room and is also used for the charging current from a regulated power supply set at 13.5V.

Inside the operating table is a 1mm aluminum sheet one meter wide which runs along the whole length of the table, this is used as the negative return.

All equipment on the operating table is grounded to this sheet which ensures one point grounding for lightning protection.

At the end of the supply line, a bank of smaller fuses supplies 12V equipment in the shack.

I plan to install an inverter eventually, which will then keep the computers running in case of power outages.

Update May 22.: Three banks have been connected for a total of 1050 Ah capacity at 12V.

12V 1050Ah battery bank float charged with Astron 50A regulated PSU set a 13.50V

Plastic sheet to prevent accidents.

6 more 2V 350Ah cells fully charged waiting to be added to the battery bank – I simply ran out of terminal lugs.

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5BDXCC

By TF4M On May 17, 2011 · Leave a Comment · In Amateur Radio

The ARRL has finished the processing of my hybrid application (both LOTW credits and QSL cards) and I qualify for what I believe is the third 5BDXCC award issued to a station in Iceland.

The previous 5BDXCC holders are Yngvi, TF3Y (with 30 Meter endorsement) and Óskar, TF3DC (with 30 Meter endorsement).

My 5BDXCC is the first in Iceland with a 160 Meter Endorsement.

In addition, I also qualify for the basic Challenge award.

My application is already in the mail. This is the result of sorting through all those old QSL cards which I had stored while I was working abroad. What a pleasure!

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Riser Bond TDR

By TF4M On May 17, 2011 · Leave a Comment · In Amateur Radio

Another new addition to my arsenal of test equipment is a brand new Riser Bond TDR purchased on eBay. A small repair was required to get the instrument to work, but the price was right.

With this instrument I get a visual picture of my feedlines and coax cables. I can use it to determine how well my Beverage antennas are working – a mismatch of the termination shows up very clearly and faults on my open wire feeders are easily located.

In addition, the instrument was very helpful when locating shorts on my 8 km long electric fence, showing me clearly which direction to walk in to locate any faults.

Lee, K7TJR pointed out on the Topband reflector:

“The Tek 465 and many other scope models can be used as a TDR
without building any circuitry. One simply needs to take the A gate
signal out of the rear panel of the scope and connect it in parallel with
the transmission line or antenna under test at the vertical scope input.
The gate signal provides a fast rise pulse on the line under test at the
beginning of the trace. Of course the sweep must be free running.
Reflections are easily seen as a result. I have used this very
technique with both single and dual direction Beverage antennas.”

I tried this technique with my oscilloscope, switching between the GATE signal and the signal from the Riser Bond being displayed on the oscilloscope – although the technique certainly works to show any reflections, it was difficult to get any meaningful display compared to that from the Riser Bond instrument.

The VNA2180 software will be upgraded within the next few weeks with a TDR function. That will be simply wonderful.

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