Otradalur Panorama photos
These are the Panorama photos I used to make the Virtual Tour.
Currently viewing the tag: "The Shack"
The Array Solutions QSK-Master has now been installed with the Harris RF-110A amplifier and it works beautifully.
The RF-110A had slow T/R switching making it almost unusable for my purposes.
With the QSK-Master, the T/R switching is better than anything I have ever experienced before and with the small modification I performed to control the bias directly from the unit ( a 10V control voltage at 4 mA is switched to control the bias of both driver tubes and output tubes ), the amplifier is now biased to cutoff when it is not keyed.
This ensures much less heat and less waste of power.
The amplifier is even cut off between CW characters in QSK operation.
TFM 3928 DxO
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Samúel, TF2SUT visited my station and was given a quick tour of the facilities with YL Andrea.
YL Andrea and Samúel, TF2SUT
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The new Harris RF-110A Radio Frequency Amplifier has been installed and tested.
The amplifier has 2 x 4CX1500B tubes in parallel in the output stage (3000W plate dissipation) biased for Class AB1 operation and runs an easy 1 kW output in any mode (key down forever…) on all bands.
It takes 100 W from the exciter through a 30dB attenuator which provides 100mW to a pair of 8122 tubes running in Class A (capable of around 1kW by themselves) which amplify the 100mW signal to 10W to drive the PA tubes.
The amplifier is cooled with a very noisy 4″ muffin fan rotating at 11,000 RPM – a real screamer – necessitating installation in the adjacent soundproofed equipment room.
The T/R switching is rather slow and clunky by today´s standards – on the order of 200mS until full output is reached due to timing constants in the bias circuit which prevents hot switching of the relays, but by increasing PTT to generated RF delays in the equipment everything functions reasonably smoothly.
An ArraySolutions QSK Master unit is on order to use with the amplifier – once this unit is installed there will be no moving parts inside the amplifier.
The RF-110A generates 3.5kW of heat for 1kW of RF output – this makes it necessary to improve ventilation of the equipment room. It consumes 1kW in Standby mode.
I would appreciate comments on the quality of my signals as I test the unit.
From top to bottom: Harris AM-7224 1kW amplifer, Harris RF-110A 1kW amplifier
Harris AM-7224 1kW amplifer and two power supplies for the AM-7224 amplifiers.
In addition the station has a Harris AM-7223 500W amplifer, an Emtron DX-2SP and an Emtron DX-3 amplifier.
Start Slide Show with PicLens LiteTF4M was honoured to have Peter, VE3SUN and his wife Jane visit the station and tour the antenna farm during their short visit to Iceland.
Peter is the webmaster of the NCDXF International Beacon Project.
Peter, VE3SUN @ TF4M
XYL Jane and Peter, VE3SUN @ TF4M
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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.
Start Slide Show with PicLens LiteThe 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.
Siggi, TF3CW was going to activate TF4X in the CQ WW 160 meter contest, but unforeseen circumstances caused him to cancel.
Yuri, K3BU, has stepped in and will operate the station in the Single Operator High Power category.
I sincerely hope that there will be no sun spots and no Aurora.
This may be the last chance in our life time to enjoy these fantastic conditions on Top Band.
I also hope the activity will reflect this – it would be so very cool if Yuri was able to work All 40 Zones in the contest !
It is interesting to note that I have followed the Tesla Radio Club project for years and several times I have been on the verge of writing to Yuri to invite him to my station !