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Author Topic: SWL Antenna question....  (Read 2136 times)

Offline East Troy Don

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SWL Antenna question....
« on: August 21, 2018, 0114 UTC »
I currently run my Grundig 750 with an Alpha Delta SWL Sloper positioned from approximately   90 degrees to 270 degrees.  I recently purchased a FRG-7700 and would like to run the Yaesu  thru a secondary antenna positioned 90 degrees perpendicular to the Sloper (0 to 180 degrees).  I have 2 questions:  Can I run both antennas off the same 25 foot mast and (2) will I run the risk of signal cancellation due to the proximity of the radiating elements?
Ok, maybe a third question....would I be better off using a vertical for the FRG at the top of the mast?
I appreciate any help on this, everyone.
Thanks,
Don
Primary: ICOM R75 W/WV-601 passive loop masted @ 20'  Secondary: Yaesu  FRG 7700 W/MLA-30+ indoors. Tertiary: Grundig  750. Tecsun PL-990X, Tecsun PL-880 . Malahit DSP SDR V3,  . : Also, Qdosen DX-286, 1940 Mantola am/sw tube. CountyComm GP-5/SSB hand held, Tecsun PL-380 ,et al.  QTH: FONTANA, WI  USA.  Sea Level: + 990' .  75 miles (but not far enough) NW of Chicago

Offline Josh

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Re: SWL Antenna question....
« Reply #1 on: August 21, 2018, 1859 UTC »
Try them all, add a vertical to the mast as well as the other sloper or whatever it is you intend to add. I'd also have some antenna switching capabilities too. By shunt feeding you can extract rf from the mast itself.

http://www.qsl.net/w9rb/webdoc9.htm


http://www.vias.org/radioanteng/radio_antenna_engineering_02_03_04.html


As to signal cancellation, the conditions would have to be ideal, meaning you will likely never find them. Something to consider however is the fact that antennas typically reradiate 2/3 of the received signal, only 1/3 of the received energy gets down the line to your rx. If you have more antennas nearby, their reradiations may increase overall rf extraction. This is why yagi and other beams work.
« Last Edit: August 21, 2018, 1903 UTC by Josh »
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Offline pinto vortando

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Re: SWL Antenna question....
« Reply #2 on: August 21, 2018, 2201 UTC »
Try them all, add a vertical to the mast as well as the other sloper or whatever it is you intend to add. I'd also have some antenna switching capabilities too.

x2

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Offline East Troy Don

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Re: SWL Antenna question....
« Reply #3 on: August 22, 2018, 0139 UTC »
Very helpful stuff, guys -  Mucho appreciado!

Don
Primary: ICOM R75 W/WV-601 passive loop masted @ 20'  Secondary: Yaesu  FRG 7700 W/MLA-30+ indoors. Tertiary: Grundig  750. Tecsun PL-990X, Tecsun PL-880 . Malahit DSP SDR V3,  . : Also, Qdosen DX-286, 1940 Mantola am/sw tube. CountyComm GP-5/SSB hand held, Tecsun PL-380 ,et al.  QTH: FONTANA, WI  USA.  Sea Level: + 990' .  75 miles (but not far enough) NW of Chicago

 

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