900 Spectra Front End Modification
Posted: Sun Jan 25, 2004 4:36 pm
Okay, I've been fiddling with the spectra front-end for some time (off and on). While fiddling, I decided to try somethng. I used solid 14 AWG wire. I put the wire through the hole in the cavity and soldered it to the back of the cavity. I was only able to do this on five of the cavities (there are six). I trimmed the length to about 1/2" or so. I swept it, and it made a significant difference, but still not optimal...
The result: Rec sens at 902.6375 went from too high to measure with my sabilock 4031, to .37 uV. A litle more fine tuning and I hope to get it down to about .2 uV or so... May be a pipe dream. At least the sensitivity is now better than, say, an Icom RP1620 (which has a nasty rated sensitivity of about .5 uV @12 dB SINAD).
The sweep showed that it was pretty low at the other end of the band, which is kind of nice, as it'll prevent desense.
If someone want's pics, let me know... I'll post them in case my description is hard to understand.
Stay motivated,
Head
The result: Rec sens at 902.6375 went from too high to measure with my sabilock 4031, to .37 uV. A litle more fine tuning and I hope to get it down to about .2 uV or so... May be a pipe dream. At least the sensitivity is now better than, say, an Icom RP1620 (which has a nasty rated sensitivity of about .5 uV @12 dB SINAD).
The sweep showed that it was pretty low at the other end of the band, which is kind of nice, as it'll prevent desense.
If someone want's pics, let me know... I'll post them in case my description is hard to understand.
Stay motivated,
Head