Posts by: TF4M

Digging for gold

By On · 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.

2011 05 28 14 17 22 DxO
  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.

2011 05 28 14 17 43 DxO
  TF4M (photo by TF3Y)
2011 05 28 14 26 10 DxO
 TF4M (photo by TF3Y)
2011 05 28 14 26 37 DxO
 TF4M (photo by TF3Y)
2011 05 28 14 26 53 DxO
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 On · 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.

TFM2986
 

TFM2995

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.

tf4m 3244
 

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.

TFM3001
 

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

TFM3004
 

Plastic sheet to prevent accidents.

TFM3005

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 On · 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.

5BDXCC qualify
 

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 On · 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.

TFM2982
 
 

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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Vector Network Analyzer

By On · 2 Comments · In Amateur Radio

A recent addition to my arsenal of test equipment is the ArraySolutions VNA2180.

With this instrument I am able to measure the isolation between antennas to determine safe working conditions of the station.

These measurements show that it is safe to have two stations working simultaneously on any band without the use of Band Pass Filters.

A TDR function will be available with the VNA2180 with the next software update.

DeltaMatrixSwitch isolation test
Delta Electronics Matrix Switch isolation test 1-180MHz
DeltaMatrixSwitch isolation test1 51MHz
Delta Electronics Matrix Switch isolation test 1 -51MHz
USArhombic to EU JA rhombics
Isolation between the USA Rhombic and EU JA Rhombics – separation of these antennas is around 700 metres.
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Arctic Shack

By On · 1 Comment · In Amateur Radio

The TF4M radio shack at night.

Sorry for the poor quality of the photos, it was more difficult than I anticipated to photograph the equipment with all the bright lights in the total darkness.

Pizzicato

By On · Leave a Comment · In Amateur Radio

A TDR locates cable and connector faults in all types of coaxial and twisted pair cable.

The Pizzicato Pulse Generator is an elegant TDR (Time Domain Reflectometer) device. 

Although the Pizzicato is not calibrated, it is easy enough to determine distances to faults given the velocity factor of the cable being tested and relative to the total length of cable as shown on the oscilloscope display.  

KB6NU´s log mentions this as being available as a kit and eventually I purchased a kit from Bruce, KD8APB who still has kits available.

 
TFM2823
Pizzicato
TFM2796
My Dummy Load
TFM2797
USA Rhombic – feedline 1300 meters long
TFM2805
The Arctic King – feedline 700 meters long
TFM2807
Eu Rhombic
TFM2808
JA Rhombic
TFM2809
SEA Rhombic
TFM2810
AF Rhombic
TFM2811
80m Delta Loop – feed line 200 meters long
TFM2812
Remote Antenna Switch – no antenna selected
TFM2813
EU Rhombic faster sweep time
TFM2814
JA Rhombic faster sweep time
TFM2815
SEA Rhombic faster sweep time
TFM2816
AF Rhombic faster sweep time
TFM2817
80m Delta Loop faster sweep time
TFM2818
Remote Antenna Switch – faster sweep time
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9L5MS – Sierra Leone

By On · 1 Comment · In Amateur Radio

Just before going to sleep, I decided to check 160 meters.  

Only one very faint signal was heard on the whole band and a closer listen revealed that it was 9L5MS in Freetown, Sierra Leone.

A quick look at my log showed that I already had 9L confirmed on Top Band, but I decided to test the power of the Arctic King and call them anyway since they did not have many callers.

I am not really surprised anymore at the power of the Arctic King – what marvellous DX!

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