Re: LF: MF DOPOLE

["mal hamilton" <g3kevmal@talktalk.net>]

Stefan

3000 km is not the problem. The problem is finding someone else on 500 with a Permit to operate, a suitable RX and proper Antenna for the job like the DXers do on 160 then it is easy.

 

Your MAGIC on 160 meters with a low dipole was the 600 Watts even with a high angle of radiation some  RF will have made it to the USA

 

Try QRP with a low dipole and see how you get on !! with the long haul DX

 

 

G3KEV

 

----- Original Message -----

From: Stefan Schäfer

To: rsgb_lf_group@blacksheep.org

Sent: Wednesday, July 25, 2012 1:02 PM

Subject: Re: LF: MF DOPOLE

Am 25.07.2012 10:37, schrieb mal hamilton:

MF

I tried a full size Horizontal dipole up at 12 metres high for 160 metres some years back and it was NO GOOD for DX long haul

Maybe not for DX but it would be OK for many people to cover a range of 1000km! In /p with QRP power levels there is no DX to be expected anyway.
Will be interesting to see if there are significant QSB effects compared to a vertical. But this will be very hard to interprete...

On 160m i used a 130m lazy loop in 8m height and worked the US in a CW contest, running 600W. The main lobe may show to 90 deg but anyway something is radiated at low angles.

Transmitting, however it did work well on Receive

I was able to receive East coast USA stations at good strength both on CW es SSB but they had difficulty or could not hear me  running 400 Watts to the antenna.

When I changed over to a 1/4 wave inv L with a vertical height of 20 metres I was able to work every one that i could hear including ZL es VK plus all the W stns as far as W6/7 es VE7

Because the dipole was so low the angle of radiation was too high and the transmitted RF had fizzled out on long haul.

Surely the dipole will not as good as a 30m inv-L. But just for fun, on holidays or fielddays or for those who have no 30m inv-L (!) it may be an alternative. And it is fascinating :-)

Locally it was probably ok but this was not my aim.

I have a 25 metre mast available at present and thought about an inv V dipole for 600 metres as an experiment but it would be so low at this frequency and exhibit high angle radiation that it would be useless for long haul but probably very good around EU

So maybe it would perform even better in EU QSOs, maybe with lower QSB. How many MF QSOs (not the QSX 7033 kHz stuff) outside a range of 3000 km have you done?

73, Stefan/DK7FC