So sorry! Don’t be disappointed when trying to use your trap. Sometimes it takes quite a while to get the first one. It’s easier once you have a decoy in the holding area. You’ll eventually catch your first one in your repeating trap but it’s much easier if you get one by trapping in your bluebird box with the Van Ert trap or trapping in your T-14 with a trap.
You need to check your trap regularly. Never leave it if you’re going to be out of town. It will catch native birds. I suggest going to the store and getting a bag of white millet seed or at least mixed seed that has a lot of white Miller in it. The black oil sunflower seed will work but will draw in a lot of native birds. Once you have a decoy in the holding area make sure you put water and food in it to keep those decoys alive so they can bring in other sparrows.
Don’t remove sparrow nests but instead let the sparrow get comfortable with the compartment and then use an inbox trap to catch them.
I think a universal trap would fit in your T-14. But I’ll ask for you. A good Facebook group for info on purple martins is Called “purple martin landlords, wannabes, and those that just enjoy them.”
Tammy