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I was in the process of questioning the 1/2 wavelength that you were using compared to the center frequency you ended up with, but when I looked back to check something---the length had changed. This is a rewrite!

It is not a problem, but I suggest tuning thru the working feed line is iffy business using either an inline meter or an anlyzer. And, for sure if we don't know what the match is at the feed point the line is likely to show us mixed results unless we are lucky and the tuned 1/2 wave line is cut for the frequency that our antenna is tuned to.

In your case you were likely very close since Steve gave you the numbers, so using the feed line probably did not make a difference. But I still ask, how do we ever know for sure that the line is not affecting what we see. If we see a flat reading at the radio end, that is fine for the radio, but the true match at the antenna still might not be what we think.

Your example of using the 4' jumper to the switch from the meter pretty much confirms that problems can develope in our measurements when using a feed line. I assume what you are suggesting is that you had a flat match at the antenna because the line was a tuned 1/2 wave multiple feed line and showed you on your analyzer that the condition at both ends of the line were the same, meaning a true match. If that were so, then doesn't the rule tell us--that if we have a true match or very close, then the line length does not matter.

BTW, I checked my old notes and I find plenty of my R, X, and SWR readings that are real close to your reading @ 26.372 mHz, R=42, X=14, SWR=2.01, but none of them are anywhere near 2:1 SWR. This might not be a good analysis of what goes on with SWR, but that is what I see.

I just don't have the confidence I once had in my analyzer. Maybe this is would be true for me with all of them when a long feed line is involved.

Did you tell Steve you wanted to tune somewhere around 27.500 - 27.565 somewhere? If not, where and did it make you wonder why you ended up in this area? During the scanning of your frequencies did you ever see a point in the bandwidth range where you saw R=50 ohms?

Good luck,

i dont get it, r=77 x=0 is not 1:1 vswr neither is r=66 x=0,
none of the readings you listed are 1:1 vswr,
if the antenna was 1:1 at the feedpoint then changing jumpers would have very little to no effect on the readings discounting the miniscule difference in loss between the jumpers,
i dont know how other people are doing it but i look for r=50 x=0 band center,

heres how my i10k tuned using the chart before i played with the trombone,

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The importance of an antenna having good radiation characteristics cannot be overemphasized.

Ok guys I will try this again.

The very first post gave the reading with nothing in line - 259b, feedline, antenna.

The lowest "R" readings is 60 on the band and at this point is where the meter is showing a 1:1 and X=0

Marconi you are right, I did go back and change the 1/2 wave lengths, I was thinking of what I have in my mobile, which is 15', sorry about that.

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5 element Yagi horizontal since '76
I 10K since '07

(Have worked 188 DXCC with a $265 ant. and a 30 watt radio - 11 m)

CDX 178
WR 178
2SD178

Oh and to your other question.

I asked Steve for center to be 27.385 which it is R=64, X=0, SWR 1:1
Then when I get to around .575 R drops down to 60 and X and SWR are still the same.

__________________

5 element Yagi horizontal since '76
I 10K since '07

(Have worked 188 DXCC with a $265 ant. and a 30 watt radio - 11 m)

CDX 178
WR 178
2SD178

x=0

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V7 = 43-5/8"
H3 = 45-1/4"

8)

dxman, r=64 x=0 is not 1:1

r=77 x=0 is a little over 1.5:1

you are seeing changes in ohms but all at x=0 and the analyser is telling you that is vswr=1:1,
its also telling you that r=188 x=0 is only 2:1vswr,

sounds like the analyser is broke unless somebody can come up with an explanation:?

__________________
The importance of an antenna having good radiation characteristics cannot be overemphasized.

Robalo,
I agree that it is best to shoot for R=52 & X=0, but I am not really concerned that much with this antenna. I know I could probably re tune it a little better, but I have no need to.

This is just a secondary antenna for me, I am not concerned with talking beyond 40 miles with it. As long as X=0 and the SWR is 1:1 with R +/- of 10, then I am happy.

I have a Maco 5/8 that I have been using and it works just fine, but I bought the 10k because I know now that the Maco will probably never survive the winds we have here. There was one in the area here that bite the dust last year with a 45 mph wind.

__________________

5 element Yagi horizontal since '76
I 10K since '07

(Have worked 188 DXCC with a $265 ant. and a 30 watt radio - 11 m)

CDX 178
WR 178
2SD178

That is correct.

__________________

5 element Yagi horizontal since '76
I 10K since '07

(Have worked 188 DXCC with a $265 ant. and a 30 watt radio - 11 m)

CDX 178
WR 178
2SD178

have any of you taken the time to adjust the trombones? I set the shaft length and ground radials per the math formula provided. the swr was off using the sugested trombone settings. using the mfj259 i adjusted the trombones ( one of them 2 in) and got 1.0 swr and 50 ohms across a very wide range. x was 0

i cant recheck and report back due to the tower is down since im selling the house.