5 MHz / 60m band - the next frontier

Motivation:

The amateur radio shortwave spectrum has been extended to the 5 MHz range recently.

At the closing meeting of the 2015 ITU World Radiocommunication Conference (WRC-15) on 27 November 2015, amongst the Final Acts signed into the International Radio Regulations was one approving A Worldwide Frequency Allocation of 5351.5–5366.5 kHz to the Amateur Service on a secondary basis.

The ITU's enhanced band allocation limits most amateurs to 15 watts effective isotropic radiated power (EIRP), with some countries allowing 25 W EIRP.
The ITU allocation will come into effect January 1, 2017, after which each country's national administration must formally revise their rules to permit amateur operation.

So far there is a hotchpotch of different channel- / block- and frequency allocations, differing from country to country.
Hopefully this situation will be cleared within the near future.

However, this Wikipedia article gives a superb overview on the current frequency allocations in the 5 MHz / 60 m band.

Receiving:

Prior to December 2016, german amateur radio operators were still waiting for a frequency allocation of the 5 MHz / 60 m band from their regulation authority.
So we were restricted to receive-only operation.

The image below shows the receive coverage up to November 2016 using the following equipment:

- a PA0RDT mini-whip receive antenna.
There are several kits available in the Internet, even fully assembled antenna and power-feed units.
But you may also set up the PCB yourself by milling a single-sided copper-plated board.

- my good old Alinco DX-77 TRX

Transmitting QRPp:

After the german regulatory authority granted amateur radio allocation on 5 MHz in late December 2016, I set up a magnetic loop antenna.

The loop has a trapezoid shape with ca. 6 m circumference.
It is made up of 9 parallel braided copper wires of 0.5 mm² each (so it is a loop with 1 winding).
Resonance is achieved using ca. 1 m of RG-62 coax used as a cylindrical capacitor.
With an additional 1:3 balun I could transform the loop impedance up to ca. 50 Ohm for coax feeding.

Using the Magnetic loop calculator by DG0KW, I have calculated the loop "gain" as -13 dBi.

With 200 mW (23 dBm) TX output and the above simulated antenna gain,
I have calculated an equivalent isotropical radiated power (EIRP) of ca. 10 dBm EIRP (= 10 mW EIRP)

Reception reports received so far:

Possible upgrade from QRPp to QRP:

In the next step I have already prepared a 25 W amplifier.
Using it far below its capability (ca. 5 W output), the achieved radiated power may be ca. 250 mW EIRP.

Due to the good results with 10 mW EIRP so far, the amplifier rests in the shelf ;-)

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