D.I.Y. tempco sensors

[Mike I]

Has anyone tried using a small DIP reed relay ( some 12V and 24 V models 
have 1000 ohm coils eg. GORDOS 831A-5) for a tempco resistor? These 
could be glued to the top of a CA3046 dip and provide a positive 3900 
ppm temp coefficient which could be adjusted with a resistor to +3400 
ppm. These relays are readily obtainable and cost around $4 US. Probably 
would need to use them in a voltage divider configuration since they are 
probably quite inductive. Bulky, yes, but they give the proper tempco 
(and a lot better than winding your own copper resistors).