Hi everyone,
I’m a beginner in designing antenna, I have a question about the white part on the back of my v-dipole antenna for receiving NOAA and METEOR M2.
Will it interfere with reception? It is placed high on the roof.
Howdy,
Regarding antenna mountings: Anything within 1/2 wavelength from an antenna, becomes part of the antenna. So it is prudent to keep an antenna at least 1.5 wavelength away from any conductive thing.
Regarding the antenna type: Low noise preamplifiers are not expensive anymore, so a small V antenna with a preamp will work.
Cheers,
H.
Looks like some active uhf+vhf antenna, like those on campers.
The white part is a radome for the uhf antenna and also the preamp.
It is also directional, pointing to the horizon.
If you want to cover satellites that pass overhead, you should point it with the white part up and the two elements in a inverted vee configuration. Do note that the water ingress protection might not work as intended in that orientation.
Also possible to tune the length’s of those to better match 137MHz, not sure how long they are now.
Hi,
Thank you very much for your answer.
Does this mean that a mat with a conductive material should be avoided ?
Hi,
Thanks for the reply
And yes, I recovered an old camper antenna but just to directly attach my 2 poles and connecting them to the coaxial output already present on this type of antenna.
But therefore, in this case, it just serves as a support, does it still have a harmful effect on the antenna knowing that it is not conductive ?
Hard to say really, I would simulate or A/B test it. like building a simple inverted vee with a choke and see how it performs in comparison. what works depends on the RF environment as well, using a wideband preamp in a high noise or close to broadcast tv/radio transmitters can be a bad idea.
