dipole in my apartment...... swr....

[oldslowchevy]

i have been using a home made dipole for the past 3 years but in the last 3 months or so my swr will be 1.1 one day then 2.3 another day 4.0 one another and so on. there is nothing loose, nothing new nothing has changed at all when this all started. the weather has no impact on it either i have tried but a different meter and a few other radios with no improvment.

i run no amps, just barefoot with the highest watt radio being 14 watts rms, the lowest is 6 watts rms. i run both 11 and converted 10 meter radios.

can the coax go bad? the connetion is fine and i get little to no change moving the coax around.

i was told by a friend of mine to put a balun on it...... i didn't have the heart to ask him what that is but thanks to this site i atleast now have a clue though i am not completely sure what it does.

i have not had any issues at all for almost 3 years so why now?

the other thing that seems to happen though i am not sure if my friends are messing with me or not, when the swr is betweeen 1.4-1.7 i have had many people tell me i am hitting them a tad harder and i am up to 25% louder? and it make no difference which radio i am on.


anyone have a clue?

and no i can not put an antenna up outside.

 

[oldslowchevy]

anyone?

 

[Robb]

Not much that can go wrong with a dipole - is right.

Tried checking the coax connector/solder joints?

 

[oldslowchevy]

Not much that can go wrong with a dipole - is right.

Tried checking the coax connector/solder joints?

as i stated in my post all is tight and soild. swr at 6 pm was 2.5-1 and right now it is 1.3-1? what gives.......

 

[Robb]

as i stated in my post all is tight and soild. swr at 6 pm was 2.5-1 and right now it is 1.3-1? what gives.......

Then; start over and make a new one if you think it is the coax.

How do you have the ends of the dipole wires suspended?

 

[chassis221]

Is there a possibility that maybe its some sort of electrical device in your apartment or someone elses that can make your swr change? id like to try an indoor antenna in my apartment also.

 

[oldslowchevy]

Then; start over and make a new one if you think it is the coax.

How do you have the ends of the dipole wires suspended?

plastic zip ties every 12" coax is supported also by zip ties also from 6" below the solder connection every 12" to the floor.

 

[Robb]

Zip ties?

I guess you might look up 'A dipole for your CB base station" and read up on how to do it right. It should be suspended AWAY from things; not up on a wall like a FM antenna for your stereo system. A transmitting antenna has particular requirements for consistent performance. Can't imagine it working at all mounted on a wall w/o having SWR issues. Been there; done that.

http://www.worldwidedx.com/cb-antennas/31857-dipole-your-cb-base-station.html

 

[Moleculo]

Are the ends of the dipole elements near any other objects like a tree that might be moving in the breeze causing the SWR to fluctuate?

 

[oldslowchevy]

Are the ends of the dipole elements near any other objects like a tree that might be moving in the breeze causing the SWR to fluctuate?

i am guessing you did not read the title....:tongue:

i figuered it out, it was a broken wire inside of insulation of one of the elements, i made a new one using much heavier wire, and all is right with the world again.

 

[DuckSoupe]

apartment dipole

I bought a 10 meter dipole with balun attached . I did not want an antenna on the roof . It is in my computer room on the second floor of my house . I basically just listen . It is a horizontal ( V ) configuration . My SWR is 1:5 from
27.185 up to 28.450 . Thats all I need without an antenna matcher . I have a Vanco SWR meter in-line so I see what is happening . The ends of the antenna has metal loops which I use command strips and plastic ties to hold it up . It's all I want except I am buying an antenna switcher as I have a few Vintage radios I want to run off it too . In the middle of the spectrum I use matches to a 1:1 .

 

[W5LZ]

A few things.
An indoor antenna is always a compromise, no getting around it. Expect less performance than if the same antenna was outside. But, if that's how you have to do it, then do it. It beats not having an antenna.
Anything 'near' that antenna is going to affect it's electrical characteristics, mostly SWR since that's what's most commonly used to 'measure' an antenna. That 'effect' doesn't have to be huge, but it's always going to be affected in some way. That isn't always a terrible thing, it can be 'fixed'/worked-around.
As you've described it's placement (room with computers and other electrical things), that's gotta be a really 'dirty' RF environment . If something can produce electrical noise it's a good chance that you are going to hear it through that antenna. the 'cure' is to quiet everything down (good luck!) or move the antenna away from all that stuff (another, good luck!). Do what you can, then live with it (we all do).
Baluns. They change things from a 'balanced' state to an 'unbalanced' state, that's all. They can also make changes in impedance, but that's not their primary purpose. A dipole is a balanced antenna, coax feed line is unbalanced. If that balanced to unbalanced thingy is causing problems then a balun can certainly help. But baluns are not a 'cure-all' by any means. If you've not been using one and it doesn't seem to make any difference then I'd have to say that I wouldn't worry about it a lot.
The SWR changes. Yep, it sure will, because of a number of reasons. Movement is one, but since it doesn't sound like it'll move very much I doubt if that's what's cause an SWR change like you described. changing frequency alwo can make a big difference. SWR is the measurement of the changes in impedance. One of the things about impedance is that it is frequency dependent. Big changes in frequency will mean a correspondingly big change in impedance matching or SWR. If the dipole is designed for one band, then moving to a different band is going to mean an SWR change. That's probably the most likely reason for the big SWR changes you're seeing. Power doesn't change SWR except with the meter that's used to measure it, they usually have to be recalibrated for that power difference. That's about as good a guess on 'why' you're seeing it as I (anyone) can make without knowing a lot more about 'how/when/where' it happens.
Howz that for an 'unhelpful' post??
- 'Doc