TS-590S internal AT

[K1PJR]

Just received the rig two nights ago.  I have a 120 ft end fed longwire.  I checked the SWR with a Rigexpert AA-54 and the highest was 80M at approx 6.5:1.

The TS-590 instructions say the tuner can handle up to 10:1 SWR's.  I tried loading on 80 and the tuner shut off.  I tried again and nada.  Switched to 40 and had no problems.  I was thinking of getting a THP 200-AT but anyone know why the tuner couldn't handle the mis-match?

BTW, I already love this rig!

Tnx
Phil
K1PJR

[G4IJE]

The data I found on the Kenwood website says the auto ATU handles up to 3:1 SWR. Handling 10:1 would be pretty amazing for an internal ATU. I think you are expecting too much.

[AC5UP]

The operative concept here is the alleged phrase: "up to a 1:10 SWR".

There are many ways to get to 10:1 in terms of reactance values and as you've discovered there is a consideration for the frequency.  Design a matching circuit for 160 and another for 10 with the same matching range and the physical differences should be obvious.

Before you spend more money, try a little experiment:  If it's not too inconvenient, lower the free end of your 120' longwire and fold 8' to 10' of the wire back on itself.  Just fold it over so the antenna looks that much shorter.  Alternatively, temp-splice a 10' length of scrap wire on the free end and let it dangle.  A slight change in the size of the antenna could be all you need to move the reactance to a place where the tuner can deal with it.

BTW:  If you really want to spend money, just send it to me...... All donations are gratefully accepted.

[WA3SKN]

The TS590 shows a 3:1 matching range... 16.6---150 Ohms, that's not 10:1!
The Ten Tecs are the only ones I know of that attempt a 10:1 range with a built-in tuner.  A external tuner, manual or automatic, should help you out though.
73s.

-Mike.

[W8JX]

Just received the rig two nights ago.  I have a 120 ft end fed longwire.  I checked the SWR with a Rigexpert AA-54 and the highest was 80M at approx 6.5:1.

The TS-590 instructions say the tuner can handle up to 10:1 SWR's.  I tried loading on 80 and the tuner shut off.  I tried again and nada.  Switched to 40 and had no problems.  I was thinking of getting a THP 200-AT but anyone know why the tuner couldn't handle the mis-match?

BTW, I already love this rig!

Tnx
Phil
K1PJR

You are beyond the range of 590's tuner and honestly I would not try feed a non resonant end feed antenna directly with that rig anyway.

[K1PJR]

I just looked at the owners manual and it doesn't state what the max. SWR is.  It says if the SWR is extremely high (more than 10:1) an alarm sounds.

It then says "if the tuning does not finish even though the SWR is smaller than 3:1 readjust the antenna system". 

Before I tuned on 40 the analyzer said I had a 3.5:1 SWR and the rig tuned it in a fraction of a second which leads me to believe it can tune SWR's higher than 3:1.  Anyway, thanks to all for the advice.  I'll play with the antenna and entertain the use of an outboard ATU.

Thanks
Phil
K1PJR

[NO2A]

At 120`,you`re a little short for 80m. I would add another 10-15 ft. of wire. That length might be ok for 75m.

[N4NYY]

I just looked at the owners manual and it doesn't state what the max. SWR is.  It says if the SWR is extremely high (more than 10:1) an alarm sounds.

It then says "if the tuning does not finish even though the SWR is smaller than 3:1 readjust the antenna system". 

Before I tuned on 40 the analyzer said I had a 3.5:1 SWR and the rig tuned it in a fraction of a second which leads me to believe it can tune SWR's higher than 3:1.  Anyway, thanks to all for the advice.  I'll play with the antenna and entertain the use of an outboard ATU.

Thanks
Phil
K1PJR

Phil,

Most radio internal tuners are 3:1. If you are hell bent on using it in that range, you are better off with an LDG autotuner or something similar. Not sure what your space it, but I built a trap dipole for 20-40-80 and in an inverted V, that may fit in the same space.

[KU3X]

Changing random wire length is one way and is worth trying. Another suggestion is to put a 4:1 balun in line.

It takes a lot of work to make a random wire work properly. RF is the shack can be a big issue seeing it's not a balanced antenna.

Barry, KU3X

www.ku3x.net

[K1PJR]

Barry,

The antenna does have an UNUN and I do have a line isolator at the shack end of the coax.

I had contacted the builder a few times on the phone, Bruce NU0R, and he helped me resolve any issues.  Really nice guy.  The internal ATU works fine from 10-40, I'll just have to get an external for anything above 40.  Working on that now.  LDG has one for Kenwoods that looks interesting. KT-100.

73
Phil

[KU3X]

Since you are getting an external tuner, look at the MFJ 929. The main reason is, "the 929 will handle up to 1600 ohms and the LDG will only handle up to 800 ohms."
I have both the LDG for moble and I have two each MFJ 929's and the 929's do a much better job.

If you want to continue to experiment with what you have, replace the 4:1 unun with a 9:1.

The problem you are having is an impedance problem. Since your wire is close to a half wave on 75 meters, you are
looking at an impedance of over 2000 ohms and that is why your rig's tuner can not handle such a high mis match.
By going to a 9:1 balun or unun, you will resolve your 75 meter issue.

Barry

[NR4C]

the cheapest route to try is to add wire to the antenna.  As has already been suggested, add 10 to 20 ft to the antenna, and see what happens.  If it works, or gets better, adjust as needed.  Don't add the complexity of an external antenna tuner unless it's absolutely necessary.

...bill  nr4c

[M6GOM]

The TS590 shows a 3:1 matching range... 16.6---150 Ohms, that's not 10:1!

That is incorrect and came about from some lazy gimp at Kenwood copy'n'pasting the TS480 info.

I have tested the tuner in the TS590 and it will match 10:1 but as someone has already mentioned you can end up with a 10:1 SWR with massively varying figures of reactance and resistance, some of which the internal ATU can't match.

However here's my 2p worth.

DO NOT USE A SHACK END ANTENNA TUNER. They're what, in my opinion, idiots who know no better use once you're using them for any more than a slight mismatch. Any sensible person uses an antenna coupler. With a shack end ATU even though the rig sees 1:1 the high SWR is still there on the coax between the tuner and the antenna so you will get additional losses because of this. With my inverted L and its unmatched SWR of >85:1 on some bands, those losses can be quite significant and remember those losses are both on TX and RX so not only will you not get out as far, you'll not hear as much either.

An antenna coupler such as the SGC230 which connects directly to the antenna feed point avoids all of that. The SWR the rig sees is what is on the coax.

A long standing amateur at my club disagreed with me quite vehemently. He recently came across the chance to get a MFJ antenna coupler quite cheaply so gave it a go on his inverted V doublet. Not only can he hear stuff that wasn't possible before, he is able to work stations with 100W barefoot that he couldn't do running his linear amp at full tilt.

[WB6BYU]

Let's look at what we know of the situation:

...I have a 120 ft end fed longwire.  I checked the SWR with a Rigexpert AA-54 and the highest was 80M at approx 6.5:1.

A 120' end-fed wire will have a high impedance on 80m - perhaps
2000 ohms or so.  It then becomes critical exactly how the wire fed and
the grounding system incorporated.  If there is some sort of matching network
(or a quarter wavelength of ladder line to make a Zepp feed) then the SWR
might be usable.

If the coax is connected directly to the wire, then the SWR will be very
high, and we have to suspect that the SWR is beyond what the analyzer can
measure, or that there is an inadequate ground system that is contributing
to the radiation and thereby changing the SWR.

Now it might be that, due to the high SWR, there are high coax losses
that are causing the SWR to be lower at the shack end of the coax.  But to
make sense of the situation we really need to know:

1) how the antenna is connected to the coax (if it is)
2) What is connected to the coax shield at the feedpoint
3) the length and type of the coax
4) Where you measured the SWR using the analyzer

With the antenna as described, I'd guess the SWR should be > 20 : 1,
depending on the coax losses.  With the SWR significantly lower than that
I'd guess there are other factors at work here other than simply the matching
range of the tuner.

[K1PJR]

Last two posts were interesting.

The logic of using a coupler seems....well....logical!  If you can eliminate the high SWR at the feedoint you won't have to worry about feedline losses or common mode currents.  Although I did read a post elsewhere where a fellow tried both the SGC and a manual tuner and didn't notice much of a difference in performance.  I suppose it depends on the antennas SWR.  If it's not that great than either type would work well but if it's very high then the coupler seems the way to go.

At a Yahoo group someone mentioned that he was also using a TS590 and a 120' LW.  He solved his 80m problem by adding a 5-12' "stub" to the UNUN and some 25' radials.  Before I drop $500 I think I will try adding the stub and radials.  If the SWR drops considerably then maybe the internal ATU will solve my problems.

To the last poster.
I'm using 100' of RG-213 which is connected to the 9:1 UNUN.  There are no radials.  The only ground is an 8' ground rod for a lightening suppressor.  As I mentioned above, I'll add a stub and radials and see what happens.

Thanks for all the input.  Not having a technical background can be a bit confusing regarding many radio topics.  But I find if you keep reading and searching the net, eventually you will come away with a pretty good understanding of how things work.  You may not become an expert but at least you can converse intelligently.  Of course don't forget to get your hands dirty.  That's the fun part

73
Phil