Re: Sony M37W
Hi Rick,toggle quoted messageShow quoted text
Is the filter you are referring to from the 8dwa seller in Poland the Murata CFWLA450KJFA? (Old part #CFWS450IT?)
In the chart shown in his auctions, this is the narrowest 450 kHz filter available, but it is not 2.2 kHz, but +/- 2.0 kHz, for a total nominal bandwidth of 4.0 kHz.
Also, I see that the stop band attenuation--at only -50db instead of the usual -60db-- is a rather poor figure of 15 kHz total. Thus the shape factor is not very good.
An alternative filter to consider and which I'm currently using in a Sangean ATS-909X as a narrow position replacement is the CFWLA450KL6A002-B0 (what a mouthful!). This filter is 2.8 kHz and works very well as a narrow AM or SSB filter. For AM mode use, it helps to offset tune by 1 kHz for the best sound quality.
This 2.8 kHz, 450 I.F. filter goes by the ICOM part number of 2020001470. It's available for $10.07 each at ICOM America. It's used as a stock narrow filter in the ICOM PCR-1000, PCR-1500, and PCR-2500 receivers.
Last week I stopped by ICOM's parts department in Bellevue and they have some of these in stock.
--- In ultralightdx@..., Rick Robinson wrote: