I did something similar when I owned a wood frame 2-flat on a
residential lot in Chicago. I had an 80M dipole that was inductively
loaded to fit between my skyhooks, and matched well on 40. I fed it with
vintage Belden 75 ohm KW twinlead that I'd found years before at a
hamfest. Tied both sides of the feedline together, so it became a tee
vertical. It worked better that way on 80 than loading it as a dipole,
because it wasn't very high (about 40 ft).
73, Jim K9YC
On 4/8/2021 8:34 AM, Joe wrote:
Correct Jim!
This is an old trick for those that have zero room for a 160 meter
antenna. We often did this and loaded the whole shebang to be able to
get on 160.
Joe WB9SBD
On 4/8/2021 12:36 AM, Jim Brown wrote:
On 4/7/2021 7:38 PM, Dave Cole wrote:
Is this true, and if so, why?
No. With the shield disconnected, the antenna is different -- if
there's an effective choke at the top, it's now a long wire ending at
the choke, because the shield and the center are capacity-coupled
together. And if there's no choke at the top, it's a top-loaded long
wire.
73, Jim K9YC
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|