Leaf Yellowing

[IMM]

Hi all - I am beginner grower in Long Island City, NY. I have several phalaenopisis which are OK. I also have this orchid which I believe is a Dendrobium? It has tiny flowers that are fragrant. I can't figure out where it wants to be. Right now it is in my bathroom in an eastern facing window. Am I overwatering? Under? Too much sun? Too cold? Help.
I recently repotted it but the yellowing was prior to the repotting.

[estación seca]

Welcome to the Orchid Board!

Without a tag it's hard to be specific. There are many different kinds of Dendrobiums with different growing requirements.

It looks like it might be Den. kingianum or a hybrid with that. These like plenty of air at the roots, lots of water when making new growth, and less water in winter - but not no water in winter. They need cool nights in the 55 F / 12C range to flower well.

I suspect the yellow leaf got too close to the window and has cold damage. What are your growing temperatures? How are you watering?

[IMM]

I either water in my shower or I soak the entire mixture every week or so in the sink and then drain. Room is in the 60's now - in the summer it gets fairly hot in the morning. I will move away from the window and put back on the floor. I had put in the window because I had read they need to be cold to flower.

[claypot]

Don't forget that orchids, like all other plants, drop their older leaves as they grow fresh ones. Dendrobiums drop lower leaves quite naturally as canes progress so don't be too worried.