|Joined:||Sat, Jul 7th 2012, 16:27||Roles:||N/A||Moderates:||N/A|
|If I am Tx'ing a VHF GrndWave of how much value is a Beam Antenna?||Jan 6th, 16:54||4||219||on 14/1/14|
|Impedance per current General Manual p.6-6/fig.6-5 ?||Nov 13th 2013, 16:48||1||169||on 13/11/13|
|Why is 72 Ohm Impedance center feed point desireable?||Oct 2nd 2013, 21:10||3||274||on 3/10/13|
|Impedance Matching HF||Aug 1st 2013, 22:18||3||497||on 3/8/13|
|Folded Dipole 40M||Aug 1st 2013, 22:04||3||460||on 17/9/13|
|If I am Tx'ing a VHF GrndWave of how much value is a Beam Antenna?||xof7fox||on 14/1/14|
|Thank you Zack.
Thank you Martin.
- Fred K4XXK.
|If I am Tx'ing a VHF GrndWave of how much value is a Beam Antenna?||xof7fox||on 6/1/14|
|I am struggling to understand the value of a Beam Antenna for 2 Meters IF I am Transmitting an FM Vertically Polarized Groundwave. And, in advance, I thank you for taking the time to read this Post and, further, trying to advise me if you can.
HERE IS MY QUESTION: Does a Beam/Directional help me push the FM Groundwave past the otherwise LOS limitation by some anticipate-able % greater amount?
Meanwhile, with regard to all of the above I do understand that:
1. A Beam will help me Receive (this Q is exclusively about Transmitting).
2. If I am going after a bounce off of Meter/or 'equivalent' Scatter, or making it to a satellite or the space station then the Beam adds to my effective Transmit distance.(this Q is exclusively about Groundwave/LOS, not Skywave).
|Impedance per current General Manual p.6-6/fig.6-5 ?||xof7fox||on 13/11/13|
|While in the current General/Level 2 Licensing Manual (7/1/11-6/30/15) on Page 4-18 "Impedance" is defined as: "...a general term for the opposition to current flow in an AC circuit caused by Resistance, Reactance or any combination of the two."... the Figure 6-5 (GLM0003) on Page 6-6 graphs Impedance over perfect ground per height of a Half-Wave Dipole in Wavelengths, yet it does not say, unless I am missing it, IF the Impedance is that of Resistance OR Reactance. Should the reader assume that the Impedance in Fig. 6-5 is purely Resistance (i.e., that Reactance is zero)?
Many thanks in advance to anyone who can offer to me some guidance on this matter.... Fred K4XXK
|Why is 72 Ohm Impedance center feed point desireable?||xof7fox||on 3/10/13|
|Thank you for your time, your thoughts and your guidance Zack.
Am heading to Amazon for Antennas by Jack D. Kraus.
|Why is 72 Ohm Impedance center feed point desireable?||xof7fox||on 2/10/13|
|Hello - I have read more than one ARRL article that report that the typical 40 M coax single wire center feed dipole in theoretical 'free space' can be expected to provide a 72-73 Ohm Impedance at the center feed point. My confusion has to do with wondering why I would want that if I should be matching the center feed point with the 50 Ohm Impedance signal coming at it from my Transceiver. In other words, if there were some other wire design/composition that would offer 50 Ohms at the center feed point would that not be more desireable? Thx,