Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > The Amateur Radio Spot

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 09-04-2012, 03:46 AM
catman's Avatar
catman catman is offline
catman
 
Join Date: Jun 2008
Location: Queensland, Australia.
Posts: 73
Ever had an antenna...

G'day all,...that never worked as well as it should have? I love my single 20 m Quad loop and it works quite well, but I don't think that it has ever worked as well as it should have, or am I just expecting too much? Regards, Felix (vk4fuq) aka catman.

Last edited by catman; 09-04-2012 at 03:48 AM. Reason: Spelling.
Reply With Quote
  #2  
Old 09-04-2012, 09:24 AM
old_tv_nut's Avatar
old_tv_nut old_tv_nut is offline
See yourself on Color TV!
 
Join Date: Jul 2004
Location: Rancho Sahuarita
Posts: 4,556
Are you asking about transmission or reception? Do you judge reception by comparison to a different antenna? Willing to be educated here!
Reply With Quote
  #3  
Old 09-04-2012, 02:23 PM
catman's Avatar
catman catman is offline
catman
 
Join Date: Jun 2008
Location: Queensland, Australia.
Posts: 73
G'day mate, stations never seem to hear me (at 100 watts of SSB) as well as I hear them. The 'law of reciprocity' should apply! Regards, Felix (vk4fuq) aka catman.
Reply With Quote
  #4  
Old 09-04-2012, 05:52 PM
jr_tech's Avatar
jr_tech jr_tech is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 3,744
SWR look ok? Any possibility that an insulator or coax could be "leaky" or breaking down at peak transmit voltages? Just WAGs on my part, I am not a ham, and don't own a transmitter.

jr
Reply With Quote
  #5  
Old 09-04-2012, 06:56 PM
catman's Avatar
catman catman is offline
catman
 
Join Date: Jun 2008
Location: Queensland, Australia.
Posts: 73
G'day mate, yes all those things have been checked (many times) in looking for a reason. Regards, Felix (vk4fuq) aka catman.
Reply With Quote
Audiokarma
  #6  
Old 09-05-2012, 06:57 PM
W3XWT W3XWT is offline
3 Phase 480VAC is QRP
 
Join Date: Feb 2010
Location: California
Posts: 208
Most of my commercial antennas haven't lived up to expectations. My homebrew ones usually work better. Sometimes much better, HI!

As for a Quad loop, while I'm sure you've looked at your 50 ohm transmission line, have you looked at your 75 ohm impedance matching stub? Are you using 75 ohm cable with the same Vf as the 50 ohm?

73,

W3XWT/6
__________________
Reception Reports for Channel 37 TVDX Can Not Only Get You a QSL Card, but a One-Way Trip to the Planet Davanna is a Real Possibility...
Reply With Quote
  #7  
Old 09-05-2012, 11:04 PM
catman's Avatar
catman catman is offline
catman
 
Join Date: Jun 2008
Location: Queensland, Australia.
Posts: 73
G'day mate, I feed my Quad loop with high quality 300 ohm balanced feedline as a tuned line, into a 1:1 choke balun and the ATU here in the shack down to 50 ohms unbalanced. Regards, Felix (vk4fuq) aka catman.
Reply With Quote
  #8  
Old 09-10-2012, 08:00 PM
jr_tech's Avatar
jr_tech jr_tech is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 3,744
Quote:
Originally Posted by catman View Post
G'day mate, stations never seem to hear me (at 100 watts of SSB) as well as I hear them. The 'law of reciprocity' should apply!
Is this mostly subjective? How about S meter readings? Better yet, *real* measurements with a spectrum analyzer? Could it be that you have really good hearing and are better able to understand the transmissions when they are partially obscured by static?

Just some more WAGs,
jr
Reply With Quote
  #9  
Old 09-11-2012, 06:15 AM
catman's Avatar
catman catman is offline
catman
 
Join Date: Jun 2008
Location: Queensland, Australia.
Posts: 73
G'day mate, well I've had stations who were S9 plus 20 db (very strong signals) received at this location yet they claimed that they couldn't hear me!

For a while I was sure that I was beng snubbed, but I've been assured that this was not the case.

This is my Quad loop along with all my experiments, warts and all including dumb mistakes! http://www.mds975.co.uk/Content/amat...tennas_03.html
Regards, Felix vk4fuq aka catman.
Reply With Quote
  #10  
Old 09-11-2012, 07:32 PM
jr_tech's Avatar
jr_tech jr_tech is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 3,744
Quote:
Originally Posted by catman View Post
G'day mate, well I've had stations who were S9 plus 20 db (very strong signals) received at this location yet they claimed that they couldn't hear me!
Yikes! Is there any pattern to this, such as stations that are about the same distance or direction?

jr
Reply With Quote
Audiokarma
  #11  
Old 09-11-2012, 08:00 PM
old_tv_nut's Avatar
old_tv_nut old_tv_nut is offline
See yourself on Color TV!
 
Join Date: Jul 2004
Location: Rancho Sahuarita
Posts: 4,556
Forgive me for asking things that I expect you have tried, but...
Is there anything else in your rig that is used with this antenna and not others? Is there a possibility of different modulation levels, for example? I also believe in the reciprocity principle, so the disparity between reception and transmission success is most peculiar.
Reply With Quote
  #12  
Old 09-11-2012, 08:18 PM
catman's Avatar
catman catman is offline
catman
 
Join Date: Jun 2008
Location: Queensland, Australia.
Posts: 73
G'day all, I've checked and cleared everything as ok. As I mentioned in my Quad loop page at one point my loop was actually facing the wrong direction (since corrected) which has helped a lot but now my loop is vertically polarised whch gives it good low angle radiation and a 'nearly' omnidirectional pattern (3 db down off the loop ends).

However this is where it gets a little grubby and human factors possibly apply. I do have regular skeds with a Ham friend in vk3 (Victoria) weekly with no problems and signals are on average around S7. My friend uses only a random length dipole similiar to a G5RV in length.

I did mention 'snubbing' earlier. I suspect that this does actually happen. I have Aspergers Syndrome (I'm an 'Aspie') and my personality is 'different', and I suspect that for this reason other Hams around Australia (vk) 'pretend' that they don't hear me. I mention my Aspergers nature on my QRZ.COM profile page.

I also do newsreading for our WIA National News service and I have been advised that my spoken news items are frequently picked up by the ARRL's 'ARnewsline' news service. So in the end, you make your own judgements as to what is really going on. Regards, Felix (vk4fuq) aka catman.

Last edited by catman; 09-11-2012 at 08:41 PM. Reason: Spelling.
Reply With Quote
  #13  
Old 09-12-2012, 06:45 PM
uxwbill uxwbill is offline
VideoKarma Member
 
Join Date: Jun 2012
Location: Illinois
Posts: 47
Quote:
Originally Posted by catman View Post
I did mention 'snubbing' earlier. I suspect that this does actually happen. I have Aspergers Syndrome (I'm an 'Aspie') and my personality is 'different', and I suspect that for this reason other Hams around Australia (vk) 'pretend' that they don't hear me. I mention my Aspergers nature on my QRZ.COM profile page.
I'm sorry to say that I think you could be right. It shouldn't be that way--the ham radio hobby itself represents just about every walk of life. I think it fair to even say that ham radio puts a diverse group of people on a largely equal footing--or at least it should.

I can't be much help with the technical issues. I've never been deep into broadcasting technology and theory. While some friends of mine who are into ham radio have tried to encourage me to take it up, the simple truth is that I already have far too many hobbies and not enough time or space for them. I do take an interest from the sidelines, especially with regards to overall excellence in broadcasting.

I've enjoyed reading your posts even when I disagree with your views. I can't speak to what's going on and there is undoubtedly a lot which I do not (and in some cases cannot) know, but I can't see why anyone would react badly to making your acquaintance.
Reply With Quote
  #14  
Old 09-12-2012, 06:48 PM
jr_tech's Avatar
jr_tech jr_tech is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 3,744
Have you experienced this "one way" effect with other antennas or on other bands?

jr
Reply With Quote
  #15  
Old 09-12-2012, 07:30 PM
catman's Avatar
catman catman is offline
catman
 
Join Date: Jun 2008
Location: Queensland, Australia.
Posts: 73
G'day mate, no, not really. Regards, Felix (vk4fuq) aka catman.
Reply With Quote
Audiokarma
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 10:19 PM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
ęCopyright 2012 VideoKarma.org, All rights reserved.