2pcs 2.4X1.4X0.5inch Toroid Core,Ferrite Rings Toroid core Iron

One of these worked fine for a 9:1 unun that I made for a 29 foot random wire antenna. After winding the toroid, I connected 450 Ohms across the antenna side of the unun, and I measured the impedance on the feed side with a NanoVNA. It measured about 40 Ohms at HF frequencies - I was mostly concerned with 10m and 20m bands. I would feel ok buying these again for making an unun or a balun. I've been able to receive at 20m and at 40m with the 29 foot random wire which I think is pretty cool. This is the first random wire that I've used with the IC-7300 I just bought. I'm a Technician, so I couldn't transmit. The reception was mostly S1 not S9 for most. The other night I was receiving on 20m S5 to S9 for some stations. (I passed my general yesterday. I want to transmit on HF!)

These aren't bad cores. The listing doesnt really say the exact material, just "iron" but being a ferrite means there are ALOT of sub options out there. These are not coated but they are nice and smooth. They were well packaged and arrived in perfect condition. I measured their AL value at 1790 mH/1000 turns which may be a bit low for large high power transformer usage but they could work.

good quality, works with my RF designs..

These made a great 49:1 Balun.

Used these to make chokes for my ham radio coax. Made chokes by wrapping coax loops in the ring. It does cut down in RF noise. These are really good quality. Would buy again.