Question about 80m frame antenna

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Re: Question about 80m frame antenna

Post by Admin on Tue Aug 15, 2017 7:17 am

<response to e-mail>

TKS HARRY;ALWAYS LIKE TO BE SURE. GETTING OLD HR. BN HAM 58 YRS AND TRYING TO PASS ON IDEAS FOR HOBBY IN THE HMBW AREA ESPECIALLY. WON'T BE ARND MUCH LONGER AND THE HOBBY HAS BN GOOD TO ME. REALLY APPRECIATE YOU AND YOUR ILK OFFERING THINGS THAT A "NEWBIE" CAN DO AND USE - SEEING IT WORK.
I KINDA GOT STARTED IN THE HOBBY BY STICKING A BOBBIE PIN IN A 110 V OUTLET AT ABOUT 8 AND "SEEING IT WORK" HI 73 AND TKS AGN; RICH M KF9F

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(Thanks to those who tried and couldn't make the QSO. Back on 14.200MHz Sundays from the 24th Sept.)
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Re: Question about 80m frame antenna

Post by Admin on Mon Aug 14, 2017 4:37 pm

Hi Richard,
There is absolutely NO physical connection between the two coils.
The antenna is essentially a transformer with a low input impedance (50 Ohms) and a high-impedance tuned circuit (over 3000 Ohms)

With the dimensions given there will be a near perfect resistive match.

You can alternatively make a 50-Ohm connection directly to the loop at dead-center (shield) and + 1/3 turn, but since the loop internal and outside Diameters are not identical, "dead-center" is not half the turns. A direct connection will also give RF on the shield if not perfect dead-center tapping.

Can you please address technical questions to the www.sm0vpo.com forum, on http://sm0vpo.forumstopic.com
I tend to travel a lot and am not always available to take e-mail. There are also a lot of clever people using the forum.

Very best regards from Harry Lythall - SM0VPO

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Question about 80m frame antenna

Post by Admin on Mon Aug 14, 2017 4:36 pm

GM OM HARRY:

I NOTICE IN UR ARTICLE ON THE "80 METER FRAME ANTENNA"
by Harry Lythall - SM0VPO

THERE IS NO CONNECTION BETWEEN THE RADIATOR AND THE FEED POINTS. IS THIS CORRECT - AS IN A CAPACITICE SORT OF COUPLING?
CAN YOU EXPLAIN?
I HAVE REDRAWN IT WITH "ENGLISH" MEASUREMENTS FOR YANK MINDS.
PLEASE FIND THE DWG WITH RED OUTLINE.

TKS AND REGARDS
RICH KF9F
RICHAZ@CHARTER.NET
OR
BLUES62035@GMAIL.COM

OPEN W/ MICROSOFT PAINT

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