3
The counterpoise system is of utmost importance in antennas shorter or equal to λ/4. The
shorter from λ/4 an antenna is, the more it depends on the counterpoise system. As a general
rule we can assume that the electrical length of the counterpoise must be greater than that of
the antenna. It is preferable to place a metal grid, or many wires just below the ground
terminal of the coupler then a long piece of wire that is connected to some distant metal tube,
water pipe or the actual ground (the earth).
ANTENNAS
1.
6.5 meters vertical for 3.5 – 29 MHz, performing better on 24 - 30 MHz.
2.
12 meters
vertical for
1.8 – 30 MHz,
performing better on the lower bands.
DON’T USE MAXIMUM POWER WITH THESE ANTENNAS FOR f < 7 MHz!
3.
Horizontal wire 25 – 40 meters with a diameter at least 3 mm and a height about 10 m
above the ground .
For a real high performance, if we have the available space, it is very
good to place the wire about 20 m above the ground, between two buildings.
We note here
that anything that exists right below the antenna is considered as ground. So don’t go on
believing that if the antenna is placed 5 meters up from the roof of a building 20 meters
high, the antenna is 25 meters above the ground. The antenna considers the top of the
building as ground!
The counterpoise must be as close to the coupler as possible!
SPECIFICATIONS
Circuit type
L or Π
Input capacitance step
25pF
Output capacitance step
12pF
Inductance step
0.04μΗ
Total input capacitance
3200 pf DIPPED SILVER MICA
Total output capacitance
1600 pf DOORKNOB CERAMIC 7.5 KV
Total inductance
40μΗ (3 mm WIRE)
Used input relays (RX114012C)
19 x SCHRACK (1KV withstanding voltage)
Used output relays (GR6JNB218)
10 x like GIGAVAC (8KV withstanding voltage)
Operating frequencies
1.8 to 30 ΜΗΖ
Maximum power for 25 meters antenna
4 KWpep => SSB & CW (1 KW => AM, FM, RTTY &
ALL CARRIER MODES FOR A SHORT TIME! )
ATMEL controller
ΑΤ89C4051 - 24P
Communication with RELAYS and memories
I2C
Maximum tuning power
50 W CARRIER
Typical tuning time
1 – 4 sec.
Maximum tuning time
Memory tune time
6 sec.
0.02 sec
D.C. supply voltage
12 – 16 V
Maximum supply current
1 A
Typical VSWR ( in the tuner input )
< 1.1 : 1
Maximum VSWR (in the tuner input)
< 2.0 : 1
Protection
Static discharge (NOT FOR THUNDER FALL!)
Dimensions ( without metal holder )
Weight
39.5 x 31 x 13.5 cm
7 Kg
STANDARD CONTROL BOX WIRES
LONG RED & BLACK => 12 VDC TO TRANSCEIVER POWER SUPPLY
SHORT BROWN => +12 V TO COUPLER (PIN 1)
SHORT GREY => START TO COUPLER (PIN 2)
SHORT YELLOW => KEY TO COUPLER (PIN 3)
SHORT BLACK => MEMORY CONTROL TO COUPLER (PIN 4)