RX coax match and limiter with CMCC (common-mode current choke) in box
This is impedance matching transformer for 75 to 50 or 50 to 75 Ohm. Designed for your RX antenna system and offer more than impedance matching. There is also RF limiter which protects your RX against high power. Two transformer design offer also common-mode current filtering.
RF limiter protects your receiver against the high power RF signals and prevent from destruction. These high RF signals are common in the multitransmitter environment - contest QTH, but also it can limit strong RF peak from the close lightning. Simply, but powerful, high voltage protection limits AC voltage peaks to 65 V. Transformators work as isolation and Common-mode current filter.
Super Fuse protects against high current in the RX line and disconnect the circuit. This SuperFuse is big advantage compare to rest products at the market. Thanks to the circuit construction there is minimal problem with IMD. Limiter works for the signals higher than 20 mW.
This device do not degrade the dynamic range of the receiver. The signal which is limited by this protection is usually higher than the value which is in the dynamic range of most receivers on the market.
Main functions:
Coax impedance matching 75 to 50 or 50 to 75 Ohm Low insertion loss Diode RF limiter for signals higher than 10 dBm (10 mW) - 13 dBm hard limit SuperFuse protects circuit against current higher than 100 mA Neon lamps lights up with AC voltage higher than 65 V Common-Mode Current insulator High RF isolation Input to Output coax ground isolation
- Quality PTFE SO-239 or F connector.
Parameters:
- Impedance matching 75 to 50 or 50 to 75 depends on connection
- RF limiter output + 13 dBm (could be set to + 17 dBm by jumper)
- SuperFuse breat circuit when current is higher than 100 mA
- Neon lamp protect while > 65 V AC
- Low insertion loss
- Galvanic isolation IN to OUT
- Common-mode isolation > 40 dB @ 160m, > 30 dB @ 40m, > 20 dB @ 10m
- Enclosure IP56 - but protect it against rain and snow
Where to put this box:
In Hamshack: 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
The measured values
 limiter OFF |
 limiter 13 dBm |
 limiter 17 dBm |
 Common-mode isolation |
Related products:
 RX protection limiter with CMCC  |
 RX protection limiter with CMCC module |
 Common-mode RX filters |
 RX preamp BOX |
 small RX preamp |
 7ANT RX switch |
