10/(15)/20/40 End fed antenna kit, including 100 Watt 1:49 Impedance transformer, wire of your choice, DIY kit
An advantage of an end-fed antenna is of course the simplicity. The fact that the antenna has no feed point in the middle makes placing the antenna very easy. Due to the solid tensile stools, this antenna can be used in permanent setups. The 10/(15)/20/40 End fed Antenna Kit has a total length of approx. 20 meters. On the 10, 20 and 40 meter band the antenna can be work without an antenna tuner. An antenna tuner is required for the 15 meter band. The feed point of the 10/(15)/20/40 end fed Antenna kit is a broadband impedance transformer. This means that the end fed wire antenna with a very high impedance +/-2500 Ohms is transformed to an impedance of 50 Ohms.
Click here for an extensive construction manual of the 1:49 impedance transformer
This 10/(15)/20/40 End fed antenna kit comes with antenna wire of your choice:
Experimental Wire: This wire consists of 1.0 mm2 braided copper wire with a UV resistant black shield. The total diameter is about 2 mm. Perfect for experiments or holiday antennas. Because the core only consists of copper, this wire will stretch over time and continue to hang. The tensile force of this wire is thereby also limited.
Copper/Kevlar Wire: This antenna wire is produced especially for HF Kits in the Netherlands. The wire consists of a Kevlar core with around 1.1 mm2 tinned copper braiding. 1x 0,4 mm Kevlar en 24x 0,25 mm copper. The insulator consists of black UV resistant PE. The total diameter is about 2.5 mm. Tension force approx. 50 kg. In this way a strong, smooth and relatively light antenna wire is obtained.
Copper/Stainless Wire: This antenna Wire is produced especially for HF Kits in the Netherlands. The wire consists of a stainless steel core (7x 0, 35mm) with around 1.0 mm2 tinned copper braid. 7x 0.3 mm stainless steel and 14x 0.3 mm thinned copper. The insulator consists of black UV resistant PE. The total diameter is about 2.5 mm. Tension force approx. 100 kg. This is a robust antenna wire with a very long life span. As far as we are concerned, this is the best choice for permanently placed antennas.
This kit includes:
- 21 meter antenna wire of your choice
- 2x Stainless Steel Cable Clamp
- 1x End Isolator
- 1x Cable lug 5mm
- 1x Heat shrink sleeve for cable lug
1:49 Impedance transformer:
- IP65 enclosure 82x80x55 mm
- Ferrite toroid Amidon FT140-43
- Winding Wire 1.00 mm
- 100 pF Capacitor 1kV
- PL 259 Chassis
- Toroid mounting plate
- Stainless steel M3 6mm screws 4x
- Stainless steel M3 Spring washer 4x
- M3 Cable lug
- M5 Cable Shoe
- Stainless steel (A4) M6 strain relief
- Stainless Steel M6 Nut
- Stainless Steel M6 washer
- Stainless steel M6 Spring washer
- Stainless Steel M5 Bolt 25mm
- Stainless steel M5 Wing nut
- Stainless Steel M5 nut 2x
- Stainless Steel M5 washer 2x
- Stainless steel M5 Spring washer 2x
- Stainless steel M5 tooth washer 2x
- Stainless steel M3 Bolt 12mm 4x
- Stainless Steel M3 Nut 4x
- Stainless Steel M3 Washer 4x
- Stainless steel M3 tooth washer 4x
- As much as possible, Hang the antenna free from interfering elements
- This antenna can also be used as a sloper.
- If you can’t get rid of the entire length, zigzag also works, avoid angles sharper than 90 degrees.
- In case of common mode issues, use a common mode choke. Do not place this choke directly at the feed point of the antenna.
Joseph Barcelo –
I purchased this kit, resold by the ARRL, prior to 2021 Field Day. I had some difficultly assembling the transformer based on the supplied (US non-metric) instructions. I stumbled across the British (?) instructions, on-line, and found the answers that I had sought.
With the correct instructions, this kit is easy to assemble. It took me a couple of hours – and I am not an experienced antenna builder.
With the assembled antenna’s wire supported ~1.5m above the ground, I attached a nanoVNA via a few feet of coax to the transformer and found that the antenna was a bit long, all the SWR minimums were slightly below the ham bands. This made sense as it is easy to trim a wire shorter, not so easy to make it longer. In a few steps I trimmed about 45cm from the end, bringing the SWR minimums to the start of each band (I planned to use the antenna for digital QSOs). The nanoVNA’s graph looked excellent.
I strung the antenna between two masks about 19m apart, roughly 5m above the ground (in an NVIS configuration), and spent Field Day making FT8 QSOs using a Yaesu 450D. I was very pleased with the results.
Using the same antenna, I am now experimenting with WSPR, at 15W on 40M, my QTH just 30km west of NYC, and am being heard by dozens of hams in Europe, several in South America, Australia and even DP0GVN in Antarctica.
A nice kit that resulted in a decent antenna and lots of fun.