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This is a special Balun 4:1, It was designed for the K2 / K1 internal ATU to make it a symmeric ATU, but it can be used for any other ATU. Power is rated to < 20W

It´s a 4:1 Guanella type wound on 2 Amidon FT82-43 torroids. The Design is based on the studies of Sevick, Maxwell and the famous article of W1CQ in the great QRP Magazin QRP Homebrewer ' The measured VSWR of the balun is < 1,1 over the range 1MHz to 30 MHz. Ready made Baluns are shipped incl. individual printout.

In the mean a 100W Version of the BalUn is available, same Datas.

Click the pictures to enlarge them

This is the VSWR chart of our 4:1 BalUn

Test was made usina a real 200 Ohm resistor over the symmetrical port with an CIA-HF Analyzer. Our HP Network Analyzer shows the same results but we dont have a readout for the HP

Between 1,0MHz and 30MHz the VSWR is below 1,1
This is a look into the box of the K2PlugIn Balun. Actualy this one was used to take the VSWR chart above.

Balun  and K2
The feed will be connected by special 2mm plugs. (Shipped with the BalUn by QRPproject)
We sell the K2PlugInBalun either as a kit or ready built.

Kit PlugInBalUn 4:1  15,00 EURO
2 Original Amidon FT82-43 Torroids
1 Enclosure
2 Special Jack 2mm
2 Special Plug 2mm
1 BNC Jack
1 BNC connector
1 Enameled Wire 0,5mm
1 description

PlugInBalUn 4:1  ready made (tested and documented) 22,50 EURO
Tested and shipped with  1 bis 30 MHz original chart

Kit BalUn 4:1 to be used in any ATU
6,00 Euro
2 Original Amidon FT 82-43
1 Enameled Wire 0,5mm

BalUn to be used in any ATU,  ready wound, tested (original chart 1MHz  to 30 MHz shipped with the Balun) 11,00 EURO

To go to the ATU page of the shop click here


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