Last week on Ebay I saw a ham selling what looked like a kit for 630m. He listed it for "600m" and it had "508KHz" written in pen on the board. https://www.ebay.com/itm/600M-500kHz-Ham-Radio-Transceiver-/382353829678? This should link to the historic listing even though it has now been sold. I couldn't tell from the picture (I can only find the thumbnail now) if this was a kit for a different band, or if someone purpose-built it for 508. From what I could tell in the original photos the board had no trademarks or any info on it. CW only, if I had to guess. It seems to have a lot more than a QRP Frog Kit, which like this one also use the BNC connector out. I've often wondered why there is no board out there for the low bands. I can even source a 160m QRP kit. You'd think that someone by now would have the low band kit out there. Thought I'd share, and curious if there is a low band kit I've overlooked. I got my approval for the low bands but will probably mod the 7100 to do it short of a cheap(er) kit on the market. Juma is way out of budget for something I might try a few times.