Author Archive
Issue with my feed line.
August 27th, 2020 | 
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| Troubling reading of coax |
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| Faulty PL259 |
Last week I posted about a wonky SWR reading I was getting and I figured it may be the result of a loose PL259. The issue returned again but not as bad last week. Since moving my Endfed antenna to be able to extend the wire the coax was also moved and now has to be buried. I needed to place the coax in some PVC conduit and not direct buried underground. It was a nice day and I decided to place the coax in the PVC conduit. While I had the coax disconnected from the Endfed antenna to feed it through the PCV conduit I thought I would connect my Fluke multimeter to the coax. With both ends of the coax disconnected, I placed the multimeter leads across the centre and barrel of the PL259 just to make sure my reading was "OL" and low and behold it was not!
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| Outdoor soldering station. |
As I wiggled and moved the PL259 the reading would rise and fall. Truth be told this PL259 was a plastic moulded factor installed connector that I was not too keen on but for some reason decided to leave it on. Just to confirm it was the PL259 I cut it off the coax and then retested the coax from the centre conductor to braid and the meter read "OL" Fortunately I just installed 120-volt outlets in my shed so it was a matter of running an extension cord from the shed to an outdoor soldering station I set up to solder in a new PL229 connector.
Skunked in the 2020 NJQRP Skeeter Hunt!
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| The setup |
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| Just in case it rained |
The weather report was correct and the skies cleared and things looked just great for operating outdoor. For my set up I was going to use my Elecraft KX3 that I put together from a kit, battery power, Palm mini paddle and finally the antenna was a mag loop. I was on checking out 20m to see how it was sounding before the contest. It was not all that great but I was coping some station so the only thing to do now was to wait for the contest to start.
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| My QRP signal was being heard. |
To make a long story short I was on for over 21/2 hours and I did hear some skeeter station but only at the noise floor and they were soon gone. I had my Mac laptop with me and I was checking and found some spots but I was just not able to hear ANYTHING! I did check the Reverse Beacon Network to see if my QRP CQ was being heard and it was all the way in Finland as OH6GB heard my signal.
My score for the contest was a big fat ZERO but I did get out, had my KX3 running and had a nice time outside.
WHAT THE HECK!!
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| Hard to capture wonky SWR situation |
Well back to the topic at hand, I had my cables disconnected and the 3x5 card in place as we did have some severe weather roll through town the night before. I connected the cables, turned on the radio and started my PC. My plan was to get some FT8 contacts in the log before supper prep had to be done. As my rig was transmitting my LDG 200AT pro II turner started clicking which meant it was going through a tune session. This was odd as the tuner memory already selected the sweet spot and it was proven by the SWR meter on the Icom 7610. BUT......as I continued to transmit the SWR was going "wonky" and the LDG tuner was engaging to correct the issue.
There sure was an issue and I'm not feeling good about it. My troubleshooting began and here is what I did:
- I went to antenna 2 on the Icom 7610 which was connected to my dummy load. I transmitted into it at full power for about the time of an FT8 transmission. The result was no SWR issue so the 7610 seemed to be ok.
- I then connected the LDG tuner between the dummy load and my transmitter. I know there is no miss-match but if the LDG tuner was acting up it may do it in this ideal matched situation. The result was the tuner did nothing when I transmitted.
- I do have an LDG antenna switch (LDG DTS-4) in the maze as well. Once again I transmitted into the dummy load through the LDG tuner and then the LDG DTS-4 to the dummy load. Low and behold the tuner was trying to find a match again!
In the past, I did have an LDG antenna switch with a bad relay and it seems this may be the case again. I examined the coax connections and there was one very slight loose connection. I also exercised the relays by switching from one antenna position to another and back again. Once this was done the SWR issue was gone. My BIG mistake was I did not check the conditions after I tightened the PL-259's before I exercised the relays. If I did it would have been clear where the issue exactly was. You know what they say " hindsight is always 20/20" I have not had the problem since but one thing for sure I have narrowed it down to the LDG DTS-4 switch or coax connection to it.
QSO Today Virtual Ham Expo 2020
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| The welcome message. |
13 Colonies wallpaper arrived today.
Tweaking the Endfed antenna SWR chart correction
I was reading my most recent post and something clicked.....and it was not a good "click". I looked at the posted SWR chart from my 44-foot antenna experiment and the numbers looked very familiar! Somehow I copy and pasted the numbers from the 41 foot SWR results and reposted them for the 44-foot experiment. Below are the corrected results for the 44-foot Endfed wire.
Band Freq SWR
80m 3.500 8.4
80m 4.000 9.0
40m 7.001 4.6
40m 7.060 4.6
30m 10.100 4.6
30m 10.150 4.6
20m 14.001 2.1
20m 14.060 2.1
17m 18.068 2.3
17m 18.168 2.3
15m 21.001 3.1
15m 21.060 3.1
SWR without a counterpoise:
Band Freq SWR
80m 3.500 6.8
80m 4.000 6.1
40m 7.001 3.5
40m 7.060 3.5
30m 10.100 4.6
30m 10.150 4.6
20m 14.001 1.4
20m 14.060 1.4
17m 18.068 2.0
17m 18.168 2.1
15m 21.001 3.1
15m 21.060 3.1
Tweaking the Endfed antenna.
I have been doing some reading regarding Endfed antennas and the length of 44 feet kept coming up as the length for a short Endfed antenna in small lots. My Endfed was just extended from 34 feet to 41 feet which I spoke about in my last post. My plan now was to try the 44-foot length of wire and see what the results were both using a counterpoise and not using one. This was going to be a trial project so the extra 3 feet of wire I am to add is not at this point going to be permanent.
I cut a 3-foot piece of wire and placed soldered terminal ring connectors at each end. My plan was to remove the antenna wire from the balun end which already had a terminal ring connector on it. Then bolt antenna ring connector to the 3-foot piece and the other end of the 3-foot extension that was to be connected to the balun connector. This would give me the extra 3 feet needed to extend things to 44 feet. Once the 44 feet was stretch out I found out very quickly that 44 feet is the maximum length I can use between my shed and tree.
With the counterpoise attached, I went into the shack and ran through the bands using my MFJ 259B antenna analyzer and recorded the results and then once again with the counterpose removed. As a side note, one of the best purchases I made was the antenna analyzer, it makes short work of most antenna testing tasks. I do have a second antenna analyzer which is the Funk FA-VA4 its a nice unit but because its menu-driven I find it to be a bit cumbersome. With the MFJ unit, you select the band range with one knob and with the other knob spin to your desired frequency and then read the LED readout.
Well back to the Endfed experiment and below are the results with the added 3 feet of wire.
As you can see in the picture the bungee cord allows the tree to sway in the wind but not affect the antenna with the stress of stretching. The red parachute cord you see is there as a backup if the bungee snaps. It was a nice experiment trying the 44 foot but the results were not drastic enough for me to keep with the 44-foot length. The antenna is not back to 41 feet and my curiosity has been solved.
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| Three feet of wire |
With the counterpoise attached, I went into the shack and ran through the bands using my MFJ 259B antenna analyzer and recorded the results and then once again with the counterpose removed. As a side note, one of the best purchases I made was the antenna analyzer, it makes short work of most antenna testing tasks. I do have a second antenna analyzer which is the Funk FA-VA4 its a nice unit but because its menu-driven I find it to be a bit cumbersome. With the MFJ unit, you select the band range with one knob and with the other knob spin to your desired frequency and then read the LED readout.
Well back to the Endfed experiment and below are the results with the added 3 feet of wire.
Results without a counterpoise:
Band Freq SWR
- 80. 4.000. 7.5
- 80. 3.500. 6.7
- 40. 7.001. 3.2
40. 7.070. 3.3
30. 10.100. 5.0
30. 10.150. 5.0
20. 14.001. 1.8
20. 14.070. 1.7
17. 18.068. 1.6
17. 18.168. 1.6
21. 21.001. 2.6
21. 21.070. 2.6
Results with a counterpoise:
Band Freq SWR
- 80. 4.000. 9.1
- 80. 3.500. 9.6
- 40. 7.001. 4.4
40. 7.070. 4.4
30. 10.100. 5.0
30. 10.150. 5.0
20. 14.001. 2.4
20. 14.070. 2.3
17. 18.068. 2.0
17. 18.168. 2.0
21. 21.001. 2.6
21. 21.070. 2.7
As you can see from the above results (not sure where the 1,2,3 numbers came from but I just can't seem to remove them without screwing up the chart) the counterpoise only made things worse again. The results without the counterpoise were decent on some bands (80m and 20m) but overall when the Endfed was at 41 feet it was not that different from 44 feet. The one deciding factor for going back to 41 feet was when at 44 the wire was directly connected to the tree. I was not able to add my bungee cord to allow the antenna to have some flex in it when the winds picked up and the tree started to sway. I was not able to add a bungee cord either as this made the antenna wire hang really low.
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| bungee allowing for flex when 41 feet long. |
