If you want to use the stereo channels on the RJM, you would need one cable which is TRS to 2 male XLR and another which is TRS to 2 female XLR. I can't tell from the picture if the one you suggest is this.
I'm also not sure what impedance and voltage levels are required by the RJM – the manual fails to mention these. You should contact them and ask them if it would be wise to use it with an H3000, or whether you should use a DI box, as suggested by Mr.SkyWriter. The H3000 should probably be jumpered for -10dB operation (see UM for info).
Be aware that we cannot offer much support for the H3000 family, as these are now almost 30 years old, and few people here know much about them (or were even born when they were first made).
