49:1 impedance transformer UNUN 200 Watts
- Brand: Wire Antennas UK
- Product Code: 49:1-impedance-transformer-UNUN
- Availability: 6
- Ex Tax: £36.00
An impedance transformer (49:1) to feed a high impedance, end fed (unbalanced) random wire which is likely to be a few hundred ohms, and transform it into something closer to a 50Ω (unbalanced) coaxial input. 200 watts
This is a unun ( unbalanced to unbalanced ) transmission line transformer designed to match 2500Ω to 50Ω .
It has a constant impedance transformation ratio of 49:1 from 1.81 MHz to 29.5MHz.
Technical specification :
Type : 49:1 Unun
Frequency : 1.81 MHz – 50MHz
Impedance ratio: 1:64
Input Impedance: 50Ω
Output Impedance: 2500Ω
Power Handling(CW/SSB) : 200W
Core Type : 2x FT140-43 by Fair-rite® Co.
Capacitor 100pF 3KV
Assembled and tested.
The impedance of the unun isaround 2500 Ohm, is transformes to an impedance of 50 Ohm. This impedance suits best to most tranceivers. The transformer consists of 2 primary windings and from 14 secondary windings.
This gives a ratio of 1 to 7. The voltage is therefore seven times higher than the source voltage and the current is seven times lower than the source current.
This results in an impedance transformation of 7 x 7 = 49. That
increases the impedance of 50 Ohm by a factor of 49, that makes it a total of 2450 Ohms.