Almost a year has passed since I was able to put the theoretical description of raising the mast into practice. http://dxerscorner.tikishop.de/archives/170-Aldi-Supermarket-antenna-mast-how-useful-is-it.html

The conclusion: the flagpole segments of the discounter are excellently suited to erect a pole with a height of 10 m quickly. A little preparation time is necessary.

First, the discs for the guy lines were sawn and drilled. I chose sturdy round plastic covers with a diameter of about 15 cm as the material. The length of the guy lines could not be determined in advance. They were laid out so that they could be extended at any time. A total of three guy lines are attached to the mast. The plastic covers were attached to the somewhat narrower connecting pieces on the mast segment. The diameter of these connecting pieces fits exactly for commercially available hole saws. The base of a swivel office chair was used as the foundation for the mast. This also fitted perfectly and coincidentally exactly into the lower mast segment. For additional security, the lower section was weighted down with washed concrete slabs. The guy lines (UV-resistant, tear-proof material from DX-Wire) were attached to nearby fruit trees with ring insulators.

Mast structure: The mast top consists of a round black plastic element with a U-shaped feed-through. The antenna wire is fed through here first. I use 1,6 mm galvanised woven wire. This is on a large 1000 m roll, which has been attached to a small garden trolley so that it can be unrolled. The wire can be threaded through the top of the mast without any problems and can be pulled on even at great heights.

I started with 3 mast segments inserted into each other and gradually worked them upwards. At some point you reach a point where the mast is no longer secure without guy lines. Therefore, the guy lines were then lashed tight, the mast aligned plumb and then the lines loosened by about a metre to insert another segment.

After 8 m a critical point is reached. Here you have to make sure that there is hardly any wind, you also have to be able to lift the mast plumb upwards with your hands and have a helper place another segment at the base and connect it. This procedure is repeated until all mast segments have been inserted. Since the guy ropes are loosened by 1 metre at a time, the mast can practically never sway more than 1 metre and is protected from swaying by exactly this metre. This tolerance meter has never been used by me or by the mast.

Connecting to a new mast element takes no more than 1 minute. I used 2 flagpoles to get to a height of 10 metres. Practically, another metre would also be possible, but I did without. The higher you go, the more wobbly the top can become. At the end of the construction you have to be able to lift 9 m and hold it plumb. That was enough for me, and the experiment succeeded. If someone manages to work in the 11th metre, I would be pleased to hear from you.

This mast replaces the old mast of the DDA, which is only 4.50 m high. As this antenna shape still requires a second mast top - it has a height of 9 m at the moment - I will also replace this mast with a higher one when the opportunity arises. At the moment, however, the flagpoles of the discounter are not available.

In June 2021, Aldi put a 6-piece flagpole from Gardenline on the shelf. The aluminum elements, which can be plugged together, have a diameter of 51 mm, the wall thickness is 1 mm. One element has a length of 980 mm. At the end of the flagpole is a large plastic head with grommet for a rope. Two of these poles put together gives a length of 11.76 m with 11 elements. One of the terminating elements can no longer be used in relation to this length.

At first glance, the poles are suitable for the construction of an antenna. The material is sufficiently strong enough. In order to reach a length of almost 12 m and also to erect it, 2 suitable guy sleeves should be used. Erecting the mast in its entire length will probably not work. There is a risk of breakage. Therefore, the elements should be inserted individually from the bottom to the top. During erection, the guy lines must be gradually lashed tight. So you need a few helpers for this.

At the plastic head should already be a long line to pull through so that you can later pull te antenna wire through. The mast comes with a construction manual for a concrete foundation.

The following building instructions use recycled material where available.

Assembly instructions

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• Guy ring: how a lid became a ring.

The screw cap lid of a pesto jar is the appropriate size. A 50mm hole is drilled into the lid with a hole saw. Then the thread of the lid is slightly lifted so that it can be slid over the pole. The resulting metal ring is attached to the mast with 3 small screws. To do this, first drill holes in the ring on the mast until the holes are also visible on the mast. Then continue drilling the drilled holes on the mast. The screws are fixed with superglue. The bracket for the guy ring is now complete.

Cut a 50mm hole out of the lid of an espresso coffee can (86mm). A 50mm hole is also cut out of the lid of a standard twist-off glass (85mm). The lids are placed flat together. This gives more stability. In the protruding part of the lids 3 to 4 holes are drilled, which are to take the fastenings for the guy ropes. A correspondingly long piece is then cut from a bicycle shift cable, fed through the holes and screwed on at the end with a duplex clamp. The remaining end of the clamp is also provided with a shift cable. Here comes the carabiner as a terminating element to it, which takes the guy lines. The covers are pulled over the tapered end of a mast tube. Finished is the guy line.

• Assembling and erecting the mast

5-legged bases of discarded office chairs have proven to be quite adequate for many of my mast designs. The tube of the chair should be slightly wider than the base of the mast. Two guy wires at 5 and 10 meters provide the stability needed by a mast of this height.

The mast segments are placed next to each other and the brackets for the guy lines are slipped over them.

Start with the top segment and the mast head. Here it is a good idea to either pull a rope through, which will later fetch the wire, or to pull the wire through already. I suggest the last, less experimental, variant.

The prerequisite is that the attachment points of the guy lines on the ground are already fixed. This determines the length of the lines. If the antenna wire is already pulled through, the ends should be long enough to reach them after erecting the mast! After the first or second element has been inserted, the mast must be set plumb with a spirit level. Even a few degrees of deviation are enough to make the mast stand crooked!

After 6m the mast reaches a height where it starts to sway. This is where the first guy point should be set. When inserting the remaining segments, the lines of this guy point should gradually be lashed tight. The lines of the 2nd guy point should already be loosely tensioned before the last segments are inserted. Then the guy lines are lashed and fixed so tightly that nothing can wobble.

This completes the construction of a 12 m high antenna tip. The construction of a loop antenna can begin.
 

***Thanks to Wolfgang Büschel from Germany for the Aldi-Tip in a-dx@groups.io***

 

 

Two new modules - all solar module units can be rotated - and a new 15 Ah charge controller now ensure that two batteries are charged in parallel. The total output of all modules amounts to 385 Wp. The capacities of the batteries remain unchanged at 120 Ah and 100 Ah. In winter, all modules can be switched to one battery. Another novelty: both batteries can now be selected with an I-0-II switch. So the fullest can be used without having to pull cables.

One year is long, and sometimes it's better than the previous one. What does the station look like at the end of 2018?

The question is not easy to answer. I had to fall back on the notebook after the failure of the tablet. In a 220V environment no problem, but in the 12V mode, you are constantly confronted with run-down solar batteries. The solar system could be expanded to 10 times, and even then I would not be safe from failures. Therefore, I will keep the plant in its current status. But the reasons are elsewhere. The 12 / 19V voltage converter causes slight disturbances in the MW range here and there. They were not available in tablet mode, because the power was converted from 12 to 5 V with a length-controlled power supply. That's why I plan to buy a 50 Ah Lion battery in 2019. He should supplement the existing 22 Ah Lion battery. Together with the notebook battery, I would then come to a running time of 5-7 hours. That is still little, but a bit more comfortable with a corresponding operation.

Antenna building material for a 350 m BOG. The line should run in NE / N direction, be largely invisible, and waterproof. Most of the material comes from a pasture fence shop, secret slogan: "Your partner for good MW-DX". The antenna is placed as soon as conditions permit on the neighboring meadow.

For construction: The Beverage boxes are installed in watertight HT tubes, the cables are routed through watertight cable feedthroughs. The ground wires at both ends are bolted to the ground rods. An approximately 60 m long coaxial cable is laid underground to the shack. If necessary, the ring insulators are placed in the ground at long intervals, bolted to wooden bars to keep the BOG flat and tight.

The BOG is connected to an RPA-2 Modular Receive Preamplifier by DX-Engineering.

That was quite a piece of work until the refurbished station was allowed to present itself as in this picture. The new heart of the station, a 7-port USB 2.0 hub with 12V / 5V seperate output, reliably controls the current flow to the ELAD FDM-S2. A new linearly regulated 5-V power supply ensures in the background that this works smoothly. The Trekstor Tablet still hangs on a conventional 5-V power supply without any RF interference detected so far. I used the opportunity to lay cables and devices even better than before. A downer remains: SDR-Console V.3 can not be persuaded to timed automatic recordings. It never stops with the station work. But first I'm happy that everything is up and running again - time for DX!

Due to problems with the tablet I decided to start the built of a air-sun-collector. The device replaces the woodburner inside. The pole in the middle is part of the 45 m horizontal loop.

Running a remote station means there is always something to do.

I checked the antennas after some storms and noticed that the top of the K9AY was broken. This looks like a difficult work in a height of about 8 m. I have to fix this in the coming weeks. Another antenna - the horizontal loop - doesn't work as good as before and I have to check if there is a cable break in only 5m height. [fixed: a badly connected wire]

Another duty is the connection of the big notebook, which consumes 5-7 Ah, to the solar energy circle. Connecting this notebook is not as easy as you might think. I bought a 19 V powerbank which delivers 2,5 h additionally to the notebook accu cell. But, for timed recordings with SDR Console software, the USB connection always failes if coming from a sleep state. This problem comes with Windows 8.1 and I don't know how to solve it yet. Another problem was coming up: the powerbank creates disturbances. So I wan't be able to record with the notebook. Very sad.

The Rocketec voltage converter is meanwhile broken, which is not so bad because it delivers always some noise on some bands. So returning to accu energy might be the better way. As you know the small Tablet can only run with a limited bandwidht so I am looking foreward to have a stable connection of the notebook which can run up to 6 MHz broad recordings.

I am also looking for falling prices of SSD discs to get more space on night recordings. My Toshiba 2 TB HD denies since some time to work properly.

Further plans are to connect another 100 Ah solar battery to the system and to get another 100 Wp solar panel. Charging the batteries with 1.5 Ah in average takes a long time, so a second panel and battery may help coming better through the winter. A WiFi-connection is also in planning which could mean to run the station really remote in some time from now.

Hope to get the right stuff on the Ham Radio Fair in Friedrichshafen and to see the one or another of you guys there.

73's and cugn from Giessen!