I don't remember for sure, maybe frequency expander, or just expander, Japanese radio band expander?
I'm doing this on my phone and won't be at my computer for a couple hrs atleast. My phone doesn't work the search tool. Dumb smart phone! Time to upgrade it! Then it's a whole new learning curve ball.
I had a 14 mhz expander in my GL1500 when purchased & noticed a few stations I couldnt receive. Replaced it with an 18mhz with better results. I gather this can vary depending on the frequency spreads in your patch - fortunately they're cheap. Power line on both introduced noise into my AM band though & I had to resolve that with a $14 noise filter on the line to the expander. Now works flawlessly.
Still shows the Jap display - just have to mentally add 18 to the numbers to get the frequency you're after.
The Kiwis seem to be pretty good at producing the expanders. This page gives a handy reference.