Technical Page

Antenna Formulae


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Ohms Law I=E/R
Where I =Current flow;
E= the Voltage;
and R= the Resistance in circuit

Power in watts = V*I
Where V is the Voltage; and I the Current
So Watts=Volts x Amps

Inductance in ac circuit XL= 2πFL
Where F = Frequency; and L = the inductance in Henrys

For a FREE book on Antennas Take a look at this URL

Amateur Radio and Short Wave Listener Frequency Bands we may use.

Band Frequency Dipole Length
m Mhz m
136 Khz 135.7 to 137.8 ?
600m 472 to 479 KHz 2
160 1.810 to 2.0000 78m
80 3.500 to 3.800 39m
40 7.000 to 7.200 20.12 m
30 10.100 to 10.150 14.12 m
20 14.000 to 14.350 10.06 m
17 18.068 to 18.168 7.9m
15 21.000 to 21.450 6.7m
12 24.890 to 24.990 5.73 m
10 28.000 to 29.700 4.88 m
6 50.000 to 52.000
4 70.090 to 70.500
2 144.000 to 147.000
70 cm 430.000 to 440.000
23cm 1240.000 to 1325.000
2.3 2.302 Ghz NoV only
13cm 2.310.00 to 2450 Ghz
3.400.00 to 3.410 Ghz
6cm 5.650 to 5850 Ghz
3m 10.000.00 to10.500.00
12 mm 24.000.00 to 24.250.000 Ghz
6mm 47.000.00 to 47.090.000
4mm 75.500.00 to 81.000 Ghz
2mm 134.000.00 to 136.000 Ghz

These Band Plans were taken from Radcom No 02 For 2018. We suggest that you check the plans Before you spend time and money to make sure You are within your licence conditions.

Decoding P14 data on the 6 metre beacon

Our GB3MCB six metre beacon was chosen some years ago to be part of an International Beacon Project. This involves five beacons operating on the same frequency (50.005MHz). Each beacon will transmit for a one minute slot, every five minutes in synchronised timing slots. The five beacons involved are EI0SIX, IW9GDC/B, PI7SIX, GB3MCB and OZ4BHM. As GB3MCB is now licensed for dual frequency operation it will operate for the intervening four minute periods on the original frequency of 50.443MHz.

The new six metre beacon was given to our group last year by the UK Six Metre Group. It runs a mode called PI4. You can download free software to decode the PI4 mode from

PI4 mode transmits a one minute cycle:
First it sends PI4 coded call sign for 24.33 seconds.
Then there is a pause for 0.66 seconds.
It then sends CW identification (call sign and locator) at 12 words per minute for the next 25 seconds followed by a 0.5 sec pause.
Finally, it sends a carrier until 59.5 seconds ending the minute with a 0.5 sec pause