Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old October 13th 17, 09:47 AM posted to rec.radio.amateur.moderated,rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Mar 2017
Posts: 137
Default QRZ Forums - Antennas, Feedlines, Towers & Rotors for Friday 13 October 2017

Antennas, Feedlines, Towers & Rotors

///////////////////////////////////////////
What Type of Antenna Do You Take Camping?

Posted: 12 Oct 2017 10:34 PM PDT
https://forums.qrz.com/index.php?thr...amping.584475/

Regular dipole, sloper, vertical, homebrew contraption that works? Would
like to see your home brew vs. a store bought.

///////////////////////////////////////////
Rectangular loop shape factor

Posted: 12 Oct 2017 10:02 PM PDT
https://forums.qrz.com/index.php?thr...factor.584491/

I am examining the use of a side center fed vertical loop and looking for
maximum gain. Bob Havilands book mentions SF, which I believe stands for
shape factor) of .875 to .9 as optimum, but I could not find the
definition. Does anyone know the where I can find data for an 80 and/or
160 meter squashed vertical loop with center feed in one vertical side? If
you have definitions for it I can model it in Llewellens (SP?) version 6,
if I have a starting point. Any help would be greatly...



Rectangular loop shape factor

///////////////////////////////////////////
Comments about an attic antenna

Posted: 12 Oct 2017 09:33 PM PDT
https://forums.qrz.com/index.php?thr...ntenna.584489/

Theres someone in my ham club who has extremely stringent antenna
restrictions, so I want to design an attic dipole antenna for 20 and 40 m
that fits in his attic. The idea is to use the limited attic space to
maximize the radiation efficiency on the bands that are used. I figure
these bands will be the two most commonly used bands for some time to
come. I would like to also be able to make it out common household
materials, e.g. house wiring, PVC pipes as winding forms for coils, etc.,...



Comments about an attic antenna

///////////////////////////////////////////
Calculating coax loss with connectors?

Posted: 12 Oct 2017 08:14 PM PDT
https://forums.qrz.com/index.php?thr...ectors.584487/

After getting some decent antennas, Ive been looking to get off my RG-8X
coax and into something better. I didnt know how lossy it was until I
looked at some dB figures. The longer runs certainly dont help me either.
And Im looking at getting something decent for my VHF/UHF rigs, since Im
about deaf on 432 running RG-8X.



So I can understand this theory, Ill say hypothetically, a certain type of
coax has a 3dB loss at 100 at 30mhz per a chart.



If it has 2 UHF type connectors on...



Calculating coax loss with connectors?

///////////////////////////////////////////
VHF/UHF dual band directional antenna

Posted: 12 Oct 2017 05:31 PM PDT
https://forums.qrz.com/index.php?thr...ntenna.581996/

Good day, friends.



I would like to receive your advice about the best antenna in its class I
could install.

I want to have a directional, horizontal polarization, dual band (144/432
MHz) antenna, fed with only one cable and not too long (say around 2 meters
(almost 7 feet) boom length. I have built and worked 12 elements K1FO in 2M
and 22 elements K1FO in 70 cm and both worked fantastic, but they are very
big for this new location. I could build shorter K1FO antennas, but I still
would...



VHF/UHF dual band directional antenna

///////////////////////////////////////////
75 Ohm Twin Feeder

Posted: 12 Oct 2017 05:26 PM PDT
https://forums.qrz.com/index.php?thr...feeder.584419/

For years, all the dipoles I have made are supported in the centre by a
Mast, so I have just fed them directly with coax.



However, when people have dipoles with no centre support, Im surprised more
people dont feed them with 75 ohm twin, as its so very much lighter.



Im planning on making a portable wire dipole, to rig up at temporay
locations, so will certainly use 75 ohm twin.



However . . . many years ago I remember using ordinary "figure-of-eight"
mains flex on a...



75 Ohm Twin Feeder

///////////////////////////////////////////
Need Help With My Antenna

Posted: 12 Oct 2017 03:07 PM PDT
https://forums.qrz.com/index.php?thr...ntenna.584185/

Below (hopefully) is a picture of my antenna setup. I’d be very grateful
for any help with theories or improvements. I only received my Foundation
licence in March this year, and don’t have a great deal of time to study
further. Being limited to 10watts, line losses are something I seriously
need to minimise, but I have very little money for equipment.



The reason I’m using a 4:1 balun, is that extensive testing on all bands
(except top band), shows a lower swr than when using a 1:1, which...



Need Help With My Antenna

///////////////////////////////////////////
Comet CAA-500 Mark II

Posted: 12 Oct 2017 12:38 PM PDT
https://forums.qrz.com/index.php?thr...ark-ii.584439/

Never used an antenna analyzer, and have been considering getting one like
the comet CAA-500 Mark II. I suppose when I am 80+ ft up I can test my SWR
and get real close to where my settings should be. Instead of going back
and forth to the shack and back up again.



I will be using a genie 90ft lift.


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
QRZ Forums - Antennas, Feedlines, Towers & Rotors for Thursday 5 October 2017 QRZ.com via rec.radio.amateur.moderated Admin Moderated 0 October 5th 17 10:43 AM
QRZ Forums - Antennas, Feedlines, Towers & Rotors for Wednesday 4 October 2017 QRZ.com via rec.radio.amateur.moderated Admin Moderated 0 October 4th 17 10:07 AM
QRZ Forums - Antennas, Feedlines, Towers & Rotors for Tuesday 3 October 2017 QRZ.com via rec.radio.amateur.moderated Admin Antenna 0 October 3rd 17 10:32 AM
QRZ Forums - Antennas, Feedlines, Towers & Rotors for Tuesday 3 October 2017 QRZ.com via rec.radio.amateur.moderated Admin Moderated 0 October 3rd 17 10:32 AM
QRZ Forums - Antennas, Feedlines, Towers & Rotors for Sunday 1 October 2017 QRZ.com via rec.radio.amateur.moderated Admin Antenna 0 October 1st 17 10:16 AM


All times are GMT +1. The time now is 11:15 PM.

Powered by vBulletin® Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2004-2017 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017