Thursday, June 23, 2011

Contest station SO2R Arcala


Arcala Station is situated on a 20 Hectars lot (40 Acers) about 40 km (25 Mi) to the East of the City of Oulu in the Northern Finland. The station is built for SO2R contesting, but allows to operate some multi-operations as well. Inside the hamschack there's operating position equipped with Yaesu FT1000MP MarkV radios and OM Power amplifiers and SO2R system with Win-Test logging software and microHam MK2R SO2R device.

There are seven tower all together. On top of that there are GPs and beverages for 80 and 160 meters. The hamschack is located quite in the middle of the lot minimizing the cabling to the towers. You can find more information of antennas and towers and antennas section of the web pages (under Station in menu).

The station automation is integration of microHam RF-matrix and "home made" automation. microHam RF matrix takes care of selecting the correct antennas, filter etc. according to frequency information from radios and our own part of station automation controlls the power splitters and switching the correct antennas at the towers.


Tower 2 (M2)Minimize

Tower 2 (M2) is 60 meters (200ft) high rotatable tower carrying antennas for 40M - 10M.

On 40M there's two stacked 2 element yagis and for 20/15/10M there's six stacked 10 element tribanders.

Tower 1 (M1)Minimize

Tower 1 (M1) is 105 meters high (344ft) rotatable tower. It holds 20M and 80M yagis.

On 20M antennas are 4 stacked 6 elemement yagis. Each 20M yagi has boom lenght of 18 meters (59ft) and stacking distance is 24 meters (80ft).

On 80M antenna is 2 stacked 2 element yagis. 80M yagis have also boom lenght of 18 meters (59ft) and stacking distance on 80M is 43 meters (141ft).

80M yagi at 90 meters high (300ft) during winter time.

Tower 4 (M4)Minimize

M4: 60m

Tower 6 (M6)Minimize

M6: 32m
DP 160/80

Tower 7 (M7)Minimize


If you want to build an Arcala Extremes (OH8X) style beam, you should start with measuring your property lines. Each of the four guy wires extends 120 meters or 400 ft from the tower – representing an area of 170´170 meters (550´550 ft) for a needed total space of almost three hectares. And then be ready to order needed 450 meters (1500 ft) of heavy duty tower sections. And finally make it look nice with 600 litres (120 gallons) of paint! Ready for the latest story from frozen Arcala deep North?

Height and weight of the system

Tower height 100 m (330 ft)
80 m beam 90 m (300 ft)
160 m beam 80 m (270 ft)
Total weight 39 600 kg (80 000 lbs)

Elements, gain and take off angles

160 m 3 elements, 12.9dBi, 26°
80 m 5 elements, 15.7dBi, 12°

FronttoBack ratio

160 m 20-30 dB
80 m 20 dB

Operating frequencies

1810-1845, 1845-1880 kHz (SWR < 1.6)
3500-3560 kHz (Lmatch)
3700-3800 kHz (50 ohm / current balun)

160 m elements

Weight 1600 kg, (3800 lbs), each
Length 59 m (190 ft), all elements 12m (36ft) capacitive hats
Each use 700 m (2100 ft) of tubing
Tuned with 06 µH coils at the centre
Relayswitches for turning the ant 180°

80 m elements

Length 46 m (140 ft), longest
10 m from the 160 m antenna
max windload, 70 m/s.

Boom dimensions

160 m length 71 m (215 ft)
80 m length 60 m (200 ft)
The triangular 160m boom (2.2 m, 7.3 ft) comes with a rail for walking inside it.

Tower 3 (M3)Minimize

M3: 60m

Tower 5 (M5)Minimize

M5: 42m
DP 160/80

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