e.t. - uhf indoor tv antenna

by:Max Apparel     2020-05-19
If you can\'t use the right outdoor TV antenna, you will most likely get stuck with the \"rabbit ears.
They receive ultra-high frequency broadcasts using small built-in ring antennas, while the telescopic rod is only used to receive ultra-high frequency broadcasts.
Most of Poland\'s terrestrial digital TV channels are now broadcast in the ultra-high frequency band, so only this small loop is actually used.
If you try to receive a weak signal (
For example, a large concrete structure blocks it)
With this ring antenna, it will not work very well.
This is the case with my grandma\'s apartment.
I decided to make a new antenna with simple household items.
It\'s probably more expensive than just buying a new antenna, and it\'s definitely more time consuming.
But instead of ordering on a large scale, the Jedi built their lightsaber.
Produced at an online retailer with drones-
Half a warehouse outside the galaxy.
The antenna that works in this case needs to be oriented (
But not too much)and wideband.
I chose the bow-
Tie dipoles, corner reflector and Roberts Barron.
The antenna is designed to be attached to the windowsill with a hookand-loop fastener. E. T.
The long number of the stands.
The distance between the corner reflector vertex and the bow
The tie rod can be adjusted by sliding mechanism, so the antenna is similar to the long number.
This change in distance changes the impedance of the antenna at various wavelengths, as shown in the figure2 here.
Parts and materials: Tools: use pencils, rulers and fixed squares to mark the edges of cardboard parts.
Pdf on corrugated board.
Draw the Line used to locate track parts G and H on Part L
Then cut the parts with a tool knife or scissors.
Fold the foldable edge of Part B.
Glue aluminum/copper foil to 42.
Part B is 4 cm long.
You can apply glue with the rest of the cardboard.
If your aluminum foil is less than 30 cm wide, cover the rest of 42 using small rectangular foil a few centimeters wider than the blank area.
Part B is 4 cm long and then fixed with transparent tape that does not touch the part of witch glue.
After that, the outer edge of the reflector is securely attached to the cardboard with transparent tape.
Fold the foldable edges of the L part, then cover the flaps with glue and press these flaps on the back of Part B
Glue Part H to Part L while ensuring that Part F can move freely between two part H
Then, glue the Part G on the part H and make sure 10 at the same time.
Part D 5 cm wide flap can move freely between two parts G.
Upon completion, you can place horizontal transparent tape strips below and above the rail parts G and H to prevent the entire structure from expanding too much to the side.
I designed the antenna drive element based on this bow tie antenna designer and calculated the center frequency of 600 MHz because at 490-
706 MHz at the nearest transmitter.
The designer calculated that I need a single pole with a width of 187.
4mm, 124 high.
Distance between 9mm and 10 pieces. 3mm.
I rounded the numbers to 188mm, 125mm and 12mm.
While painting the bow
Part D tie, I think (
Most likely wrong, but this error will only move the center frequency closer to 0)
I need the width of each bow
94mm tie.
I covered the area inside the edge with glue and put the foil on top of the adhesive.
I fold the foil along the edge and then cut along the newly created creases with a knife.
When glue keeps parts G and H dry, slide part F into these sticky parts and mark the edges of Part G in different positions of Part F with pencil
Fold the flaps of the Parts C and D, and then glue the 5x5 cm flaps of the end of the part C together.
Next, glue part C to the back of Part D.
After drying the adhesive, mark it with a pencil line for positioning Part.
Mark the single line in the center of the lower C section, while Mark two lines in the higher C section, each 1.
5 cm from the center.
After completion, connect part A so that the center part of Part A is online and the flap is glued to Part C.
Glue part F to both ends of the newly formed cardboard structure while ensuring that the flaps remain inside the pencil mark on Part F.
Then, after waiting for a while, you should check if the whole building can slide on the track.
When I used the TV air cable with the plug already installed on both sides, I cut one of the plugs so there was only one male Belling-Lee was left.
I then started removing insulation and shielding from the exposed part of the coaxial cable with a tool knife and removing the dimensions from Barron. pdf (
5mm of the shield is visible, 3mm of the internal dielectric is visible, and at least 10mm of the center conductor is visible).
By the time I did this, I had cut the cable off 100.
2mm after the Shield began.
Then I did 11.
Cut 2mm long diagonal at the end of the newly formed short-section coaxial cable.
I drilled a hole with 1mm drill bit 68.
From the beginning of the shield to the center conductor 5mm, remove its shorter part with pliers, while maintaining the longer part with the second pair of pliers.
Then I deleted 6.
4mm outer plastic sheath length 76.
2mm from the shield.
Next, I processed a longer coaxial cable and handled the exposed end in the same way as the other one, and also removed 6.
4mm outer plastic sheath length 76.
2mm from the shield.
When both pieces are ready, I press the two cables together (longer “edge” [
I should say \"element of truncated cylindrical surface\"]
Shorter, longer-facing parts)and joined 6.
4mm long band 0.
The copper wire with a diameter of 5mm is wound together and welded together (
Unfortunately, the cable I use with a diameter of 5mm has an aluminum shield, so the wire is just tightly wrapped around the shield, not directly welded to the shield).
Later, I connected a few centimeters of copper wire to 5mm uncovered shields.
Next, I reinforced the connection between the two pieces with a small amount of insulating tape and placed 16x5mm 0. 8mm thick PCB (copper removed)
Between 5mm long shields (
Fix it in place with tape).
To complete balun, I weld the exposed center conductors together.
Hit two holes with a small DingTalk (
About 8mm apart from each other)
Almost through the center of Part D (
They should be near the apex of the bow. tie pieces)
Between the upper. Clean bow-
Tie the surface of the fragment with a tissue soaked in alcohol.
Pass the copper through those holes.
Fix Barron with insulating tape and cardboard parts A and C.
Make the wires angled so that they pass through the bow
They are horizontal when in front of the foil.
Then, fix the center part of the wire with an insulating tape, and do the same to the outermost part of the wire.
I started with a short strip and then put more tape on it so the tape goes beyond the edge of Part D.
When the wire is fixed in place, I apply a layer of conductive adhesive between the foil and the wire, and when the adhesive is dry, I apply another layer.
If you use copper foil, you can simply weld the wires into copper.
Cover a small part of the center of the reflector foil with transparent tape to strengthen it (
Use at least a few horizontal and vertical bars).
Then, the apex of the reflector is passed vertically from the cardboard side.
Next, horizontal cutting is performed from the foil side, which will intersect the vertical cutting at the center of the reflector.
After completion, plug the cable end through the newly made opening of the reflector (
If your cable has not installed the plug yet, you can cut the smaller opening and install the plug when the cable has passed through the reflector).
Then slip the bow-
Fix the support structure on the track and pull out enough cables from the antenna so that the cable between Barron and the reflector is straight.
The antenna should work now, so you can connect it to the TV to see if it works.
You may need to locate the bow
If you have a problem with reception, please leave the bipolar farther or closer to the reflector.
Fold the flaps on the part J and slide them together so that the flaps form two surfaces that can bond the Part E.
When doing so, attach a pair of Part E with glue so that the groove on the two part E is vertical.
Next, repeat this for the remaining two parts.
Later, the adhesive sleeve of Part E was glued to the upper and lower flap surface of Part J.
During the drying of the glue, I used a few pieces of transparent glue to bring the fixed parts.
Later, fold the flaps in Part K and paste the wider flaps in Part B (
So point down)
L short portion flap (
So it points up).
The foldable edge of the K part should be at the top of the reflector vertex and support the coaxial cable.
Similarly, when the glue is dry, the parts should be fixed in place using transparent tape.
Then, the main surface of Part K is reinforced by bonding the first part, and the same reinforcement is performed on the surface of Part B 15 cm wide (
15 cm wide surface of Parts B and K should be able to contact each other).
Now, you can connect a 15 cm wide surface with a pair of clothes (
Each of them is located opposite and ideally one of them should be higher than the other).
Add \"mass\" objects (
In my case, it is a cuboid made of cardboard containing 0.
Scrap metal 5 kg)
On the side of the bracket, the top of the bottom E, with clear tape or glue.
Below, attach self-adhesive tape on the other side of the Part E group (
I used two tape 20mm wide and placed parallel to the E edge of the part).
I covered the ends of these strips with clear tape so they don\'t fall off the cardboard.
Next to the ring belt, I pasted several layers of cardboard with transparent tape so that the upper surface of the antenna bracket would be flat and the slope of the windowsill would be denied.
I put a longer self-adhesive hook strap on the windowsill.
At the center of Part B 30x30 cm, a considerable amount of transparent tape is applied on both sides.
Do the same for the center of the E section at the top of the bracket (
Start on one side of Part E and don\'t tear anything).
Upon completion, place the main part of the antenna at the top of the bracket and punch through all the tape layers at the center of the 30x30 cm rectangle.
If your bracket is already attached to the windowsill, you can now rotate the whole building around the nail.
When you find the right position, fix the antenna by connecting two caps at the edge of the 30x30 cm surface at the top of the holder.
On some pictures, you might see some extra tape that lightens some quirks of the cardboard structure in my hand (
You will definitely do better).
It is especially worth mentioning that it is located directly below the vertex of the reflector to prevent the K part from folding.
I decorated the antenna with an advertisement on page 108 of the February 1954 radio and television news.
I did this because the radio fixer character from the Erie ad looked very much like the inspiration for the jump horse boys from the radiation games series.
I used the shield power cord to ground the reflector and removed the inside.
The end of the remaining Shield is twisted, and the insulation tape is wrapped around where the shield comes out of the plastic jacket.
Two holes through the reflector (
Cardboard that supports it)were made.
One end of the shield is twisted through two holes (
On the side of cardboard)
In this way, the shielding end is firmly pressed on the metal foil.
Later, on the foil side, the shield end is covered with a layer of insulating tape, and it is pressed on the foil in addition.
On the other hand, more insulation and transparent tape is added, enough to securely attach the cable to the back of the antenna.
The shield on the other side of the cable is connected to a metal surface with good grounding (
In my case, this is a radiator and the insulating tape keeps the shield in place).
Actually, I didn\'t notice any difference in the operation of the ground antenna, but it is always recommended that the antenna reflector be grounded.
Warning: If you make an antenna with stronger material and place it outdoors, the proper grounding of the antenna is critical.
Copper wire for at least 2.
5mm in diameter is applied to connect the reflector of the antenna to the ground and to implement a more reliable method of contact between the wire and other conductive surfaces.
The coaxial cable was cut off and a signal amplifier was installed between the two ends of the newly made cable.
The wound is so far away from Baron, bow-
When the signal amplifier is still behind the reflector, it can be placed completely in front of the antenna. Male F-
Type connectors are installed at both ends of the cable.
To install this type of connector, you will need to remove the outer plastic sheath, corner braided strands of a few centimeters so that they can now surround a part of the remaining plastic sheath, and then, remove almost all visible foil and media (
The remaining part should be as long as the minimum diameter part of the connector).
And then if you have trouble
On the connector, you should screw it to the braided strands and trim any strands on the connector.
The central conductor should be cut off so that it can extend a bit from the connector.
Since my connector is a bit too big for my 5mm diameter coaxial cable, I later wrapped some insulating tape around where the cable started coming out of the connector, make sure the connector does not fall off the cable.
The signal amplifier I purchased has a male connector on the antenna side, so I need to install the amplifier using the female to female Barrel connector coupler.
The amplifier is powered from the TV end, so I replaced the original Belling-
Lee connector with special connector, connected to 12 v power supply via two wires.
I removed the cover of the connector and released three screws.
In order to attach the coaxial cable to it, I removed part of its layer so that the visible part of the center conductor is as long as it is the metal part designed to hold it, the visible part of the dielectric is as long as it is the gap between the metal part and the visible part of the shield, as long as it is the metal part designed to accommodate it.
The woven thread is twisted into a rope
It is like a completely finished structure is foil and parallel to the center conductor.
These lines are placed under a metal plate fixed by two screws, while the center conductor is inserted between another metal part and a square nut located inside the metal part.
Later all three screws were tightened and the lid of the connector was put back in place.
Next, plug the male connector of the antenna into the female connector of the TV and plug the power supply into the 230 V AC.
The signal amplifier is now in use.
Unfortunately, the particular amp I use is too strong.
To solve this problem, I installed a simple electronic circuit to reduce the voltage supply amplifier (
Should be done in case the power supply is disconnected from the power supply).
This circuit is based on 3.
3 v Zener diodes that can be connected in series with the power supply.
Make a basic physical structure, two single-knife double-throw (
SPST switch can also be used)
Connect the switch together by wrapping insulation tape around the switch (
Shorter sides contact each other).
Then, weld a 1n4728 Zener diode on each switch (
So that the switch can short-circuit the diode).
Later, the diodes were connected through short wires and a BAT48 Schottky diode was welded in series with them.
Next, the inclined anode of the 10 uF electrolytic capacitor is welded to the cathode of the BAT48, and a few centimeters long lead is welded to the inclined cathode of the capacitor.
Upon completion, the power cord coming out of the special connector is cut off near that connector and there is an insulating stripe near the newly created end.
Connector side Positive line (
You can use a multimeter or look for a white strip on the wire insulation to identify which one)
Connect to the anode of the capacitor and connect the negative pole to the cathode of the same capacitor.
On the power side, the positive pole is connected to the cathode (
Until this point, there is no connection to anything other than the switch)
The wires of the Zener diode and the negative are welded to the wires that come out of the capacitor cathode.
Later, the whole circuit was wrapped up with insulating tape (
Except for the Zener diodes, so they can dissipate heat more easily so that you can see which leads they Weld to the switch).
Now, the voltage supply amplifier is reduced by 3 when the Zener diode is not short-circuited by the switch.
3 V, which in turn reduces amplification.
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