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Problem with a diy dipole antenna.

Buffalo

Active Member
Jan 2, 2023
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I made a direct feed dipole antenna. Aluminum tubing. I’ve seen this before. It seems to be very wide banded and I get a 1.1 to 1 match anywhere I normally operate. I currently have it about 8’ off the ground. Problem is SSB. I get reflected power spikes when transmitting. With one exception. When I use the tune side of my Mfj tuner it is fine. No spikes. Ideas? California contact from here in TX awhile ago. So I’m at a loss.
 
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LOL........SSB is all "power spikes". No power output until you speak.You cannot test SWR on SSB as there is no constant carrier. Your tuner forces the radio to tx a steady carrier in CW mode.
I understand that but this isn’t normal. I’m watching the reflective power needle spike every time I talk. Doesn’t do it on my 2016 ground plane. Only happens on the bypass side of the tuner. If I switch to the tune side it’s fine. I’m not testing SWRs on SSB. Don’t think i said I was.
 
I understand that but this isn’t normal. I’m watching the reflective power needle spike every time I talk. Doesn’t do it on my 2016 ground plane. Only happens on the bypass side of the tuner. If I switch to the tune side it’s fine. I’m not testing SWRs on SSB. Don’t think i said I was.
Don’t know what the problem was exactly but it’s all good now. I had stated in my OP that I’ve seen this before. I just couldn’t remember the circumstances where I ran into this before. For some reason I was thinking coax and not owning an analyzer I decided to change it out. I also decided to eliminate the SO239 and direct feed the coax. Retuned the antenna and it’s all good. BTW I missed it before my original post AM was doing the same thing. Reflected power spikes when modulating. We will see if anything changes when I get it up in the air.
 
Did you make choke balun at the antenna feedpoint?
Just a coax coil no real balun. I kind of suspected something was wrong when I had to shorten my lengths well beyond normal to get a match. I did get what appeared to be a close to perfect match at least according to my meters. It’s normal for me to get a slight swing on reflective power needle when I modulate. But this was different. This one is going up in the air though. It’s performing really well about 8’ off the ground.
 
Got it up where I want it and everything is good. 18’ in the air. The pole is a flag pole and has one more extendable section where the flag will go. Easiest push up set up I have ever used. Pretty heavy duty pole (11 guage aluminum). Still have to seal everything and waiting on a light for the top. Only one contact today, a local about 12 miles away in his mobile off the tip of the antenna. Which I thought was pretty good all things considered.
 

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Got it up where I want it and everything is good. 18’ in the air. The pole is a flag pole and has one more extendable section where the flag will go. Easiest push up set up I have ever used. Pretty heavy duty pole (11 guage aluminum). Still have to seal everything and waiting on a light for the top. Only one contact today, a local about 12 miles away in his mobile off the tip of the antenna. Which I thought was pretty good all things considered.
Did you make your own center support / insulator thing? What's the element lengths? I've wanted to make one too. I can talk to South America with my vertical but the guy 3 miles away sounds like crap.
 
Did you make your own center support / insulator thing? What's the element lengths? I've wanted to make one too. I can talk to South America with my vertical but the guy 3 miles away sounds like crap.
Yes I made my support but it’s not the best. Out of 2 - 1/4” hdpe cutting boards I got at the dollar store. I will likely replace it with 1/2” hdpe. Each leg ended up being 102.5”. I switch to it while talking to Barbados this morning and my signal dropped from my 2016 but he could still hear me. No idea if the dipole was even broad side to him at the time. Really just having a little fun.
 

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