The Celwave dual stage isolator used for the new repeater was obtained at a local Hamfest sans it’s termination loads. So it really was a circulator at that point, and I needed some 50 ohm loads for this isolator application. My past experience with Chinese terminators of the low power variety has not been good. The ones I tested before, rated for 1W and 2 GHz, were pretty terrible at higher than VHF. Even at 145 MHz they only had about 15-20 dB RL depending on the sample. At anything over 500 MHz they were totally unusable unless you were trying to simulate a very poorly matched antenna.
With that in mind, I reluctantly ordered a 10W and 50W load from China for the isolator. I wasn’t expecting much. The price was cheap enough and I figured on replacing them with something better when decent ones could be found at a future swapmeet. The 10W load was about 13 dollars shipped and the 50 watt about 27. They arrived pretty quickly as China goes, and their external finish and quality seemed high. The question was how good of loads they were.
Surprising good..
Way better than I was expecting. 38 and 42 dB RL at 450 where they were going to live. The isolator was very happy. With the good antenna match at the site, they shouldn’t see a lot of action from the repeater TX reflected power, but will hopefully shunt the other guy’s RF to ground and keep it out of the transmitter.
Dave, K7DMK