The list (in Japanese) is at http://www.jarl.or.jp/Japanese/1_Tanoshimo/1-6_beacon/beacon.htm.
Each beacon station operated by the JARL in each area 1-0 has a JA#IGY-type call sign.
But only in the 5th area, JE5IGY is used,
because JA5IGY had been still alive as individual's call sign at that time (now already expired and vacated).
Each beacon station operated by an individual or a club uses owner's call sign.
A designator "/B" is not popular in Japan.
However, the JARL recommends to register them to the beacon list above.
Following stations are registered there.