[Milsurplus] Receiver Filter Adaptor and Thoughts on Projects In General

[Ian Wilson]

Found some details on a ceramic resonator ladder that I put together from
some of the anonymous brown 500kHz variety that used to be free from
Dan's Small Parts a few years back. Info here:

  - 50 ohm terminations
  - 0.01uF capacitors (4 of them)
  - 3 resonators
  - design bandwidth: 1kHz

Measurements, using URM-25/D with a 6dB pad between it and the filter
(filter terminated in 50 ohms):
  - centre frequency: 488.1kHz
  - 3dB bandwidth: 1kHz
  - insertion loss: 3dB

Note the 12kHz drop in centre frequency. But I'd guess that most radios that
use 455kHz will cope with a few kHz shift with no problems.

--ian

73, ian K3IMW
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20160216/8c1f2eed/attachment-0001.html>