Hi Dale,
I think most filters termination impedances are complex, not simple and pure resistances.  Lacking a network analyzer, I lean towards seeing what an end-user manufacturer did in applying the filter, then confirming or fiddling with as necessary, the response as seen on my spectrum analyzer.

Yeah, I will see if I can contact PTI......figured they would ignore a junk box inquiry from a ham, but worth a shot.  Tnx.....LC

Hi,
I have couple of crystal filters made by Piezo Technology Inc. and I would like to use them in homebrew receivers, but I don't know this filter's termination impedances.  I'm pretty sure this filter was used in a commercial/military receiver, maybe a RACAL unit, maybe some other receiver.  The receiver's schematic would reveal the impedances, so if you know what receiver used a Piezo Technology Inc. Model 1815, center freq 1750 kHz, bandwidth 500 Hz filter, let me know.  The filter is also stamped with what looks like the receiver manufacturer's in-house part number:  1920-0603.  Happy holidays to everyone, tnx, 73.....Larry  KB2EE

Hi,
I have couple of crystal filters made by Piezo Technology Inc. and I would like to use them in homebrew receivers, but I don't know this filter's termination impedances.  I'm pretty sure this filter was used in a commercial/military receiver, maybe a RACAL unit, maybe some other receiver.  The receiver's schematic would reveal the impedances, so if you know what receiver used a Piezo Technology Inc. Model 1815, center freq 1750 kHz, bandwidth 500 Hz filter, let me know.  The filter is also stamped with what looks like the receiver manufacturer's in-house part number:  1920-0603.  Happy holidays to everyone, tnx, 73.....Larry  KB2EE