OK. The internal Murata filter is CFJ455K-14 (6 Db bandwidth of +- 1.1 - +- 1.3? kHz). The boards available for around $100.00 are CFJ455K-13. I cant find a data sheet on the -13 filter but descriptions from people selling the call them a 2.7 K bandwidth filter. If that is the case then they are a little wider than the internal filter so the audio may sound a little more natural? but a close in signal would cause more interference. I don't have one so I can't give a real world evaluation but I don't think I would spend $100.00 just to find out it's not any better than the built in filter.
Pat, WA3UOE
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On 6/16/2024 12:30 PM, Pat Campbell via groups.io wrote:
The Murata filters are similar to the internal filter in the radio. Probably a little tighter bandwidth but not near as good as the Collins mechanical filters. I'm not sure what the filter number is fr the internal filter but you could compare the specs for the internal Murata filter to the specs for the plug in Murata filters offered on Ebay and other sites. If I get a little time I will open my 817 and get the filter model? number so I can compare.
Pat, WA3UOE
On 6/16/2024 11:23 AM, Kevin - K5KTM via groups.io wrote:
Understood but do they work well enough to make a difference?? I’m working on a budget and people are asking insane money for the Collins filters, be they OEM or Inrad.
Thanks
Kevin Mullens
K5KTM
