[600MRG] Antenna efficiency question

[Neil Klagge]

Good question, Jim. I can only tell you what I believe about  MY  antenna:I am pretty sure that I was getting at least 1% efficiency. It is 40' vertical with three top wires of 25' each. They come down at an angle of 40 degrees to the mast with the bottom ends dropping to about the 25' level. I usually run about 100w TPO and am getting about 1 to 1.2 watts ERP (+/- 1 dB).
Until about 2 weeks ago I had only 7 buried radials of 30 to 50 ft each, all running only N and S on the west side of my small city lot. I recently added 4 more radials under my house (thru the crawl space) and out the other side to the NE, E, ESE, and SSE which had a very noticeably positive result in stations to my east receiving me. I think it might have improved my efficiency since my ground wave signal during the daytime is up by at least 6 dB according to Steve, ve7sl, on Mayne Island, BC.
My Rr by LaPort's methods is about 0.4 ohms, and with EZnec (free demo version) it looks more like 0.32 ohms (I am just a novice at EZnec). 
Hope this info is useful to you in some way. Glad you are getting ready for the band opening. 
73
*´¨)
¸.•´¸.•*´¨) ¸.•*¨)
(¸.•´ (¸.•`   Neil KlaggeVancouver, WA

My Faith website: http://neilsfaith.webs.com/
My ham radio websites: http://w0yse.webs.com/ and http://wg2xsv.webs.com


 


> Date: Wed, 20 Apr 2016 19:26:58 -0400
> From: jim at jtmiller.com
> To: 600MRG at w7ekb.com
> Subject: [600MRG] Antenna efficiency question
> 
> Is there any "rule of thumb" that would give me a ball park number for the
> expected efficiency of my 67x67ft inverted L that I now use on 160 if I
> just added a loading coil at the bottom?
> 
> If it was (or could be) 10% and the FCC only grants 1w ERP when they give
> us an official band then a 10W amp would be all that is needed.
> 
> OTOH, if it is likely to be closer to 1% then 100w would be needed.
> 
> TIA
> 
> 73
> 
> jim ab3cv
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