806-824 RX on an 800 Spectra

[wa6jbd]

I had a need for a high quality receiver to listen to the input side of the 800 band for interference hunting, and other trouble shooting. Having shoved a few other radios outside their intended spectrum on other bands, I decided to give it a try. Low and behold, I was successful, and ended up with rated performance across the entire 800 input band.

So, I have a couple of questions... Has anyone else done this before, and if so, I'm curious how you accomplished it. If not, is there any interest in seeing a writeup? I'll probably do a couple for the other guys in the shop, so I could carefully document the process... that is, if anyone else is actually interested.

[xmo]

I would be interested in reading about your project.

Anyone who maintains an 800 system can use a receiver that listens to the input side.

It is a great tool for looking for interference, particulalrly in the latest systems where the base stations are all digital - you may get an "illegal carrier" report out of that STR or GTR but what was the actual signal?

One other way to create such a receiver is to use a Desktrac repeater receiver - or modify a Maxtrac if you can find suitable front end filters, but since 800 analog Spectras are plentiful, a mod for those would be great.

[wa6jbd]

Well, I'll go ahead and write something up about it. I'm going to do another one this weekend, so I'll document the process. BTW, the process is identical to move a 900 Spectra receiver down to 902. Basically, it involves adding 1pf chip caps to the filter, then retrimming with a Dremmel to bring it back up, and making the LO microstrip about 30% longer.