Stupid questions thread.

DjAngleGrinder

Hello, new to the hobby, have lots of questions that I'm not getting answers for from Google (possibly through my own fault).

Is there any experienced Hams (if that's the right term) on this board that would have the time (and patience in fairness) to participate in a "Stupid questions" thread where people like myself could ask about things we don't understand to try and get a simple answer?

Hopefully there will be an appetite amongst some members here

Thanks in advance

JD

4dxc

Just post them and you`ll see. Happy to give some advice if I can.

DjAngleGrinder

https://www.boards.ie/discussion/comment/120638519#Comment_120638519

OK, first stupid question:

Is the dipole antenna the best antenna to transmit and receive long range?

The dipole is to be half a wave length long correct? So if I want to listen on the 2 metre band, should each "arm" of the dipole be 50cm long?

The scenario in this case is trying to transmit and receive from two points that are unobstructed in terms of line of sight but are 40 km apart.

Can I make a dipole out of 2 bits of wire and coax or is a Balun essential?

Ty in advance

4dxc

>>Is the dipole antenna the best antenna to transmit and receive long range?

A Yagi or a Quad would be a better choice. Depending on the frequency you might want to look at vertical antenna as directional antennas get quite big on 1.8-7.1 Mhz for example. For a beginner a Dipole is a great start.

>>The dipole is to be half a wave length long correct? So if I want to listen on the 2 metre band, should each "arm" of the dipole be 50cm long?

Roughly, yes. To calculate the length of each leg you use (300000/Frequency in khz) /4. In the 2m example it would be 300.000/145.600 = 2.06m. As it`s a half-wave diople each leg is 2.06/4 = 51.5cm. Depending on the type of material you use you need to include a velocity factor. If you cannot measure you could start of with a velocity factor of 0.95 which means each leg would be 0.95x51.5cm = 0.49cm.

>>The scenario in this case is trying to transmit and receive from two points that are unobstructed in terms of line of sight but are 40 km apart. Can I make a dipole out of 2 bits of wire and coax or is a Balun essential?

I doubt a dipole will work reliably for this. You might want an antenna with more gain (Yagi). Yes, you can feed the dipole directly. However, a balun is recommended to transform the unbalanced coax to the balanced dipole.

For 2m you have to be already quite precise as tiny deviations quickly result in an antenna thats not resonant on your desired frequency. I am only transmitting on 30Mhz and below where it`s not that critical. Maybe someone who is more experienced on VHF can give you additional tips.

BENDYBINN

Who owns the internet?

DjAngleGrinder

https://www.boards.ie/discussion/comment/120639493#Comment_120639493

Thanks for that, I'm gonna research Yagi antennas, I'll be back with more drivel soon.

https://www.boards.ie/discussion/comment/120639530#Comment_120639530

Zark Muckerberg

BENDYBINN

https://www.boards.ie/discussion/comment/120640430#Comment_120640430

Would he ever decide to turn it off?

Lewis_Benson

What is 2m, 10m, 11m, and what do they mean?

cml387

Its the wavelength of the radio signal. It can also be expressed by the frequency.

wavelegth =velocity/frequency

Frequency = speed of light 3 x 10^8

cml387

https://www.boards.ie/discussion/comment/123304616#Comment_123304616

That should read velocity - 3 x10^8

By convention shortwave bands are referred to by the wavelength.

So were old Am radio stations: FAB 208 Radio Luxembourg, BBC Radio 1 on 247m

FM radio stations by their frequency e.g. FM104.

NTMB

Quick query in case anyone is still monitoring this thread. I was very interested in radio as a child and how all the European radio stations would appear at night on the AM band, together with US Forces Radio etc. I haven't looked at it in a long time but I'm looking into picking up a receiver now to see what I can pick up (probably slimmer pickings than before with many broadcasters having moved online etc). However, I'm wondering where I can find out what sort of receivers it's legal to hold without a licence? I was thinking of picking up an XDATA D-328 which has all the SW bands so should be fine; but for slightly more I can pick up an ATS 20 which apparently can also pick-up SSB/lSB also. Is it legal to own something like this without a license in Ireland? The Wireless Telegraphy Act is a bit hard to follow for the layman! 

orm0nd

https://www.boards.ie/discussion/comment/123810565#Comment_123810565

I don't there is any rules covering receivers, or if there is, it's not enforced .

As an alternative to receivers have you looked up listening on line via Kiwi SDR? There are numerous sites worldwide which give really coverage

http://rx.linkfanel.net/

NTMB

https://www.boards.ie/discussion/comment/123872600#Comment_123872600

Thanks very much for that, Orm0nd. That's a really useful link. Sorry I've only seen your message now.