I recently got my hands on some miniature DIP relays, and would like to prototype a circuit with them on a solderless breadboard. Unfortunately, these relays have standard 100 mil pin spacing, but 200 mil between rows, rather than the more usual 300 mil. Obviously I can't just put them in at a right angle... is any adapter available to deal with this? Or any cute tricks?
Best bet is usually some DIY if you have not got too many.
Use 200 mil centre sockets if available or socket strips,
or cut a socket in two and solder two strips onto a piece of veroboard/vector board/whatever you call board with copper strips with holes in it.
Solder socket to board and solder a row of pins through board outside socket so they have (probably) 400 centres which will allow plugging into a standard breadboard.
Something like below but with your two rows of socket pins in the centre and with pins to breadboard bottom soldered
You can buy pins suited to this - and I have used plated brass dressmakers pins in days of yore. The plated brass pins have about 3 million% better solderability than non-brass pins that I have tried, even though the brass is under the plating.