Consumer Radio - HAM / Amateur Radio - Antennas: Part 2b - Intro to antennas, tuning and QRM

[OrionTiger]

Continued: Antenna EFFICIENCY. Which is the antennas ability to transfer the power received to “real radio waves”, and not just heat! With an ideal antenna tuner I can make a pencil size antenna resonant to whatever frequency. BUT it is not going to be an efficient antenna for HF! So do not skimp on trying to make the antenna its self as efficient as you can! Fix the inevitable imperfectives with an antenna tuner. Dummy load => SVR 1:1 and the radio thinks it’s a great antenna! Get the picture?

[mjlorton]

@OrionTiger Thanks for your contributions good man!

[OrionTiger]

The antenna tuner should be physically placed between the antenna its self and the coax that lead the radio signals to and from the antenna and the radio. Then and only then it would really change the ANTENNAS electrical characteristics. So why do we not do that? Because it is really impractical! Remember, the coax is 50 ohms. So if the antenna is not resonant to 50 ohms, there is going to be a mismatch where the antenna is connected to the coax. Antenna efficiency is what we want! Not heat! 73

[nikonman1161732]

Trying to learn some radio theory. Right now tuning.resonance.and found you very helpful. thanks looking for more

Brian,KB7MZY

[mjlorton]

@nikonman1161732 Thanks for your feedback. I hope the future videos will help as well. Cheers, Martin.

[toddrharrison]

I'm new to ham. I learned a lot in the class but your video today made it all much clearer in my mind. I don't think I will forget these concepts now like I had when reading from a text book. Thanks very much! Keep up the great ham radio tutorials. I'm in two radio clubs and I'm trying to get the clubs to post links to these videos.

[mjlorton]

@toddrharrison Thanks very much for that feedback it is greatly appreciated. I hope the future videos continue to be informative and make it a little more understandable than the text books. Thanks for watching.

[hippyraverocker]

Thanks for sharing.

[kimdaviscali]

The antena that Martin is showing in the beginning is called and OCF, Off Centre Fed Dipole...best fed with twin lead, 300-450 ohm ladder line/twin lead which has almost zero loss for this configuration, fed down to a manual tuner or automatic antenna tuner (SGC, Icom AH4 etc), this is a great configuration provided that the ladder line/twin lead is kept away from metal objects (drains, metal fences etc).

73 Jen, aka Kimdaviscali

[kimdaviscali]

Trombone is the instrument you are referring to and make "resonant" is the key word to adjusting length. :o) 73 Jennifer (aka Kim)

[mjlorton]

@kimdaviscali Aaah...that it! :-) thanks!

[TheSurvivalSecrets]

Thanks for going ahead with this series Martin it is very interesting for me. As you said yourself it is great to refresh your memory. I thought that the level of detail was perfect, not too technical by going into the physics of it and not too simple where one doesn't understand the principals of antennas and how they work. Very well done, I am certainly tuned in for more :) ~ Jason

[mjlorton]

@TheSurvivalSecrets Hi Jason, I certainly appreciate that feedback. Cheers, Martin.

[dkaplan2005]

Great video Martin!

[mjlorton]

@dkaplan2005 Thanks for the feedback.