Noise Reduction Filter
The NRF2 is a "passive" Audio Filter, specially designed to improve audio selectivity. Its main purpose is to clean up the hash, whistles and splatter often experienced when trying to resolve SSB, FAX etc with a receiver intended mainly for AM reception.
It is a true "bandpass" filter - a 6-pole Chebyshev arrangement - with a very steep roll-off at around 2.6 kHz and 300 Hz. Selectivity is about 2.2 kHz at 6dB with negligible insertion loss.
Mounted in a neat little ABS case, measuring 7 x 5 x 2.5 cms., it simply sits in line with your headphones or 'speaker.
Input and output impedance is 8 ohms, although it will be found to work quite well with other impedance values. Connections - in and out - are by 3.5 mm. jacks (suitable for many modern receivers) but plug-in adapters are included to permit use with the standard 1/4" type. No battery is necessary
NOT sold in kit form!
Ready to use! Only £16.50
Postage (U.K.) £1.00