Tekmar 369 outside sensor interface

Harold

I have installed a new boiler system. I am using the previous zone control with existing 369 controllers. In the new configuration I need at lease one additional outdoor sensor. No way to get another wire outside. From what I gather, the 369's will not share a 10K thermistor. If I can find out what the input circuit for the 369 looks like, I may be able to make a shared thermistor work with a bit of external electronics. I have not been able to find any schematics for the 369. There is more than one way for electronics to deal with a sensor. I need to know how the 369 handles it. I do understand that the specs say no sharing. But that does not mean an external solution will not work.

Does anyone know where I can find a schematic for the 369. Or even for just the input circuit that sees the sensor.

I am rather in the rock vs hard place scenario at this point.

Brad Notter

tekmarcontrols.com/products/accessories/087.html

No wires needed when you use a 087 sensor.

Harold

Thanks.
I researched the device. It is a good idea, but it sits right on the frequency of all of my radio linked home automation equipment. I already get spooky results out of those devices. Tekmar does use a spread spectrum signal which will help their signal reliability significantly. But to the rest of my house it will be signal interference. The Tekmar device seems to be running much more RF power than the other things in the house. I also have windows which are all significantly impervious to RF, concrete first floor with hydronic piping and concrete siding. I have not had good results getting RF in or out.

A bit of paranoia: Looking at the FCC assignments, the navy and many others use that area of the spectrum rather heavily. I am quite close to a Naval Air facility that does only F18s equipped for electronic warfare and collecting ground intelligence. I am under their flight path. I have long suspected that what I get down here when they fly over is at least a possible contributor to intermittent electronic strangeness in the house. It is used for things like seeing missiles at wave top. This is a training base for all of the ECM/SIGINT F18s for aircraft carriers.

If after some more research, I don't have a solution, I can buy one and try it. But I really want to keep it on wires.