HFU HF Underground
Technical Topics => Equipment => Topic started by: ladderline on October 22, 2014, 2257 UTC
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Connected to my coax cable is about 40 feet of ParEndFedz. If I connect this 40 feet in the opposite direction to 50 feet of ladderline or 70 feet of ladderline, taped around the walls near the ceiling, what would the effect be on my Yaesu 857-D at 5 - 7 Mhz? What if I let the ladderline fall from my hotel balcony down to the balconey near to the ground? What if I let the ladderline hanged to the end of my room down from the balconey? What are the best angles? What are the best sizes (of ladderline and ParEndFedz)? I am new to the hobby. Please bear with me. I do not intend to transmit but only listen. I am asking about ladderline because it has twin wires and one of my colleagues was (I don't know if he was joking) joking that it might 'kaboom'.. And I am cognizant of the fact that the length can be measured by 300 divided by the frequency. (but it has twin wires)..
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Do you have a PAR EndFedZ for a particular band, or perhaps instead a PAR EF-SWL? Models for specific bands can be rather narrow banded since they are end-fed dipoles, but the EF-SWL is rather broadband since is essentially a longwire with a 9:1 transformer.
If it is a PAR model for a specific band, you might look into changing the antenna conductor to be 1/2 wavelength of your desired band. For example, if you want to listen to the 6.925MHz frequency, you could try a 67.6' antenna wire instead of whatever length is supplied with the PAR transformer.
Alternatively, if you have a PAR EF-SWL, then PAR ships it with 45' of antenna wire. It is decent compromise lengh that works okay with the provided 9:1 transformer for a wide swath of frequencies with little directivity on the typical SW broadcast bands. You can try a longer antenna wire, but do not expect much difference unless you start adding multiple wavelengths of wire at a desired frequency/band to increase directivity off the ends.
Now as for your ladderline, beyond just being feedline or bulk wire to harvest for a project, it can be used as an effective impedence transformer for certain types of antenna. For some ideas, take a look at an end-fed Zeppelin matched with ladderline as an impedance transformer, or even a G5RV that uses ladderline as both an active portion of the antenna and an impedence transformer to better match coaxial feedline.
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Thank you very much sir for your kind advice. I appreciate them.