This manual page is for RX Coax match and limiter device. This is impedance matching transformer for 75 to 50 or for 50 to 75 Ohm. This device is designed for your RX antenna system and offer more than impedance matching.

In this magic box is also RF limiter which protects your RX against high power. Two transformer design offers also common-mode current filtering. Protection limiter is able to protect your receiver against the high power RF signals and prevent from destruction. These high RF signals are common in the multi transmitter environment (contest QTH), this device also can limit strong RF peak from the close lightning. With the included SuperFuse you can protect against high current in the RX line and disconnect the circuit. This is big advantage compare to the best products on the market. In this technical article you can find how to use this protection limiter and where to put it to your ham shack.

Jump to

Applications
Parameters
Product details

Applications

- In ham shack: 75 Ohm coax from antenna - 50 Ohm to RX
- 50 Ohm ANT - this box - 75 Ohm coax - this box - 50 Ohm RX
- RF power limited to 13 or 17 dBm
- Diode RF limiter for signals higher than 10 dBm (10 mW) - 13 dBm hard limit 
- SuperFuse protects circuit against current higher than 100 mA
- Common-mode current insulator
- Low insertion loss

one version with PL SO-239 & F connectors

Parameters

- Impedance matching 75 to 50 or 50 to 75 depends on the connection
- RF limiter output +13 dBm (could be se to +17 dBm by jumper)
- SuperFuse break circuit when current is higher than 100 mA
- Neon lamps protect while > 65 V
- Low insertion loss
- Galvanic isolation IN to OUT
- Common-mode isolation > 40 dB @ 160m, > 30 dB @ 40m, > 18 dB @ 10m

protection effect of the RF limiter