EMRFD Message Archive 12872

Message Date From Subject
12872 2016-05-22 04:42:44 Ravi Miranda Crystal Filters - IF module
Hello everyone

Trust you are having a great weekend.

I am considering building this IF moduleĀ  here:

This will follow the downconversion of a TV tuner, so that I can listen in to AM, CW, SSB etc.
For the OSC section I intend to use a Si5351 and a PIC. the PIC would also control the display and the TV tuner i2C.

I was wondering if the filter modules are available in the UK at a reasonable price? Or am I looking at building my own sets of filters from discrete crystals? Discrete build would mean a considerable amount of testing and impedance matching I suppose, not much test gear with me at the moment.

What do you think?

Have a happy Sunday.


I'm here to add more value to the world than I'm using up.
12875 2016-05-23 08:42:07 Graham / KE9H Re: Crystal Filters - IF module

I think the problem may be the "TV Tuner".
TV tuners are designed to work with signals that are perhaps 6 MHz wide.
As such they have stability and phase noise specifications that are suitable for wide signals, but provide disappointing performance when used with very narrow signals like SSB or CW.

--- Graham / KE9H