In response to a similar query years ago, I bought these: https://www.amazon.com/gp/product/B004ESP144/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 They have been fine in the shack. Note that the wall wart they come with is very bad - throw that away and let it be self-powered or get a quiet supply. -Tony, K1KP