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Locked Whoo hoo!
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We're up to 55 members! And lots of activity.
Remember, if you have not posted yet, all new members are moderated. So don't be alarmed if your first message takes a few hours or a day to appear. I get on fairly often to check, subject to Real Life(tm). Once you've posted, I'll set you unmoderated. Just my way of quietly blocking spammers. Steve Greenfield, moderator of the new loopantennas |
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Most excellent tamales!!
A modest proposal... How about renaming the group to loop_and_compact_antennas? If the other members are agreeable to broadening the spectrum on this topic now would seem to be the time to do it rather than later when it might be more difficult to implement. Perhaps a poll? 1) Yeah, gimme more!! 2) Nah, I'm a loop purist!! 3) I got here by mistake :-/ 4) Spam, spam, spam, spam. 73, 'Bear' NH7SR --- In loopantennas@..., "Steve" <alienrelics@y...> wrote: We're up to 55 members! And lots of activity.(tm).
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Michael Stevenson
开云体育In that case, I better say hello to you all as this
is my first post to this loopy group! I am currently experimenting and
finalising the construction of a 3/4 inch copper tubing loop 14 foot
circumference. I want to tune the lower shortwave bands rather than the higher
ones. Using a large old fashioned tuning capacitor which has dual gangs with
around 465 pf per gang, using only one gang allows the loop to tune from 3.8 to
17.9 MHz successfully with high "Q" and good nulling, this is using a 1/5
sheilded RG58 co-ax coupling loop into my Icom R75. Using both gangs allows
tuning down to 2.8 MHz and I still have to experiment with adding even extra
capacitance to the second gang to see if it will get to at least the 120 meter
tropical band.
I have tried using varicap tuning diodes but their
performance and tuning range is more limited. I have also tried using a pre-amp
(featuring the Lyle circuit) both directly connected to the loop at the tuning
capacitor (which has been noisier with far too much output) and at the coupling
co-ax loop which has been much better all round although I have still had to add
an output level control to bring the input to my receiver to be around the same
or slightly higher than either of my longwires.
This new loop is mounted on PVC pipe and will be
placed outside in the middle of my backyard with an antenna rotator and a geared
motor for remote tuning of the tuning capacitor, there will also be a relay to
switch in the extra capacitance to lower the tuning range. It will be mounted
around the loop diameter above the ground.
Early indications are an extremely good performance
across most of the bands especially considering it is sitting only two foot off
my DX shack floor beside my receiver and even without the pre-amp signal
strengths on some bands, especially the tropical bands is better than my
longwires and usually always lower in noise although some bands are prone to TVI
which is understandable because the family TV is about 3 meters away from my DX
shack in the opposite room!!
The final construction and testing is well under
way and I shall keep the group posted as to the results, especially once it is
mounted outside.
Best regards to you all!
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Michael Stevenson,
Australia.
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Michael Stevenson
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Michael,
Good to see you here and eagerly looking forward to more info on your loop. Especially how you manage the remote tuning arrangement. I didn't really mean my proposal to serve as a poll of the members. That should come from Steve Greenfield as he is the list owner here and it's his decision if a poll should be done. Nevertheless, thankee fer da vote <G> 73, 'Bear' NH7SR --- In loopantennas@..., "Michael Stevenson" <portstevos@t...> wrote: 1) The more the merrier I think!topic now would seem to be the time to do it rather than later when itwrote: > We're up to 55 members! And lots of activity.moderated. > So don't be alarmed if your first message takes a few hours ora day > to appear. I get on fairly often to check, subject to Real Lifequietly > blocking spammers.---------- Yahoo! Groups LinksService. |
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Steven S. Coles
Steve,
Ninty messages in the first week! You have one hot group here! Regards, Steven --- In loopantennas@..., "Steve" <alienrelics@y...> wrote: We're up to 55 members! And lots of activity.moderated. So don't be alarmed if your first message takes a few hours or aday to appear. I get on fairly often to check, subject to Real Life(tm). quietly blocking spammers. |
Steven Greenfield AE7HD
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