Very high SWR problems

[KD8TZC]

I recently picked up a used Kenwood TS440SAT that was in excellent condition. I hooked a dummy load up on it and was able to tune it no problem (perfect 1:1 into the dummy load).

I also picked up a Radiowavz 10 meter dipole antenna with balun on it. When I fire that up and try and get the SWR, it's in excess of 6:1 in CW mode on 28.4mhz (actually, the forward needle and reflect needle are almost vertical and they do not cross)

Any ideas or am I looking at a bad antenna? Should I take it back to the store and have them hook an antenna analyzer up on it to confirm that it is the antenna? Since the feed line was used to connect to the dummy load, I don't think it is that as I would think it would read high there as well.

73's

 

[k3td]

John, what are you using as a feedline for the 10 meter dipole, how do you have the antenna mounted and how close is your rig to the feedpoint of the antenna?

 

[KD8TZC]

Tad,

I'm using a 12 foot RG8x for the feedline, the antenna is mounted inside on the wall. I have some brads nailed into the wall and the insulators on the ends of the dipole have a small hole that I place on the brads (and there is also an insulator in the middle that I do this with too). The rig is right next to the wall.

 

[LtDoc]

Either I misunderstood what you said, or you have a misunderstanding of what you are doing.
A TS-440SAT can't be 'tuned' for any frequency/band so checking it into a dummy load isn't telling you much except for it's power output and the state of the feed line used for that checking.
Anything close to an antenna affects it's "tune", where it happens to be resonant and it's input impedance. If that antenna is 'nailed' to the wall then that wall is affecting it. The antenna could probably be tuned to compensate for it's nearness to the wall but it doesn't appear that you've done that.
I don't care what it is, or who made it, all antennas need tuning to the frequency/band you intend to use them on. The chances of an antenna straight out'a the box being 'right' is about like winning the lottery, possible but don't hold your breath.
- 'Doc

 

[KD8TZC]

Doc, I understand that you can't tune a radio to a dummy load. I did that just to ensure that the feed line is not the fault. I have also moved the antenna around to different placements and I get the same results which leads me to believe that I may have a problem with the antenna or the balun on the antenna. Is there a way to test this with just a simple multi tester? Tomorrow I plan on taking it back to the shop that I purchased it from and having them hook an antenna analyzer up to it as I would think that should provide some insight.

I also agree that all antenna's need to be tuned somewhat, but a commercially made antenna should not be off the charts with regards to the SWR (unless possibly something is wrong with it). Wouldn't you tend to agree?

 

[k3td]

My guess is there is so much RF floating around inside - between the antenna itself and the RF coupled to the house wiring - that the SWR meter doesn't know what to do. suggest you try the antenna outside with 30' or so of coax back to the rig. You might also try it with the tuner in line and without when you are checking.

Good luck and 73,

 

[KD8TZC]

Well, funny you should mention this about trying it outside as that what I just came in from trying. I suspended it from some cord but was not that high off the ground. Same exact results though. I don't have 30' of coax though, so I could only use the 12' that I did have previously. I'm thinking it is the antenna myself and will take it back tomorrow to have them run some tests on it.

 

[Skypilot007]

What does the internal swr meter on the rig read in comparison the external cross needle meter you mentioned? Are you using the rigs internal tuner? If you are using the rigs internal tuner use the rigs built in swr meter to measure the SWR. If you are using an external tuner and SWR meter make sure it's hooked up in the proper sequence. Radio-SWR meter-Tuner. If you use the internal tuner and try to read SWR with an inline meter external to the rig now your meter is after the tuner. The external meter won't read correctly in that configuration.

 

[LtDoc]

Do I agree that there's something obviously wrong with that antenna? No, I don't, sorry. First, you should be putting it in a 'reasonable' location using 'normal' care in doing so. As you had the thing mounted, isn't reasonable. I have no idea what I would expect from it, but it certainly doesn't sound like what you have is unreasonable all things considered.
Checking the thing with an analyzer -when it's erected where it normally would be used- is a very reasonable thing to do. Doing that checking at the place where you bought it isn't gong to tell you anything useful. But take it back anyway, see what 'they' tell you.
- 'Doc

 

[ab3a]

Take an ohmmeter, and test your coaxial cable without being connected to the Balun. You should read an open circuit. Also, check to ensure that you have continuity all the way down the transmission line by shorting the connector before it gets the balun.

Next, connect the balun and measure the resistance from center pin to shield in your shack. It shouldn't be more than an ohm or two.

If ANY of this fails, you have a problem. The first indicates a coax problem, in which case installing a new connector will help, or the second indicates a problem with the balun.

The way your radio is acting, I think there almost has to be a dead short somewhere, probably in an antenna connector.

 

[KD8TZC]

Do I agree that there's something obviously wrong with that antenna? No, I don't, sorry. First, you should be putting it in a 'reasonable' location using 'normal' care in doing so. As you had the thing mounted, isn't reasonable. I have no idea what I would expect from it, but it certainly doesn't sound like what you have is unreasonable all things considered.
Checking the thing with an analyzer -when it's erected where it normally would be used- is a very reasonable thing to do. Doing that checking at the place where you bought it isn't gong to tell you anything useful. But take it back anyway, see what 'they' tell you.
- 'Doc

And what is wrong with the way I am erecting it Doc? Not everyone can put an antenna outside. Ideally I would love to but with the deed restrictions we have in the HOA, I just can't. I have read countless articles of people installing an antenna indoors as that is all they can do. I realize that there may be limitations in doing so and I will not get the same performance I would if it were mounted outside. Everything I keep thinking is there is something wrong with the antenna. Issues do arise with manufacturing them, and possibly there is a short someplace. Also I did use normal care where I have it installed, so I don't know where you get the fact that I didn't. I also tried the unit outside last night in a temporary setup (suspend with rope) and the readings were almost identical as what I had in the room on the second floor.

To the others who mention testing the Coax alone and then connected to the balun. I did do that yesterday. Coax tested out just fine on the ohmmeter. When I connect the coax back to the balun (and antenna), it jumps all over the place and never levels out. I tried a second multitester as I was concerned there was an issue with the first, and it had the same result. Needle jumping all over the place.

Skypilot.. the internal SWR meter pegs all the way up (10 on it's scale).

- John

 

[Skypilot007]

I just thought I would bring up the meter situation as I have the same radio and had similar issues with SWR before someone set me straight about using an external meter with an internal tuner.

I know a lot of folks who have had some success on HF with indoor antennae, mostly attic mounted. It will be a stretch to make contacts on 10 meters with the antenna indoors even if it tunes up good or has a good match out of the box. You never know thought, I wish you luck with it.

 

[KD8TZC]

Okay, just got back from the radio store where I bought the antenna. I also brought the coax just to make sure. They tested the coax and all was fine with it. The antenna they decided they would just take it outside and hook a rig up to it and see what it yields. It pegged their SWR meter all the way up too. They didn't bother to do anything more with it and just exchanged it out. Hopefully that will resolve the issue.

They stated that even though I am using this indoors, I should be able to get a reading on my dual meter SWR meter without getting two vertical needles. We'll see what happens when I try it out later tonight.