Hi, I have recently returned to playing after too many years. I originally played cornet and flugel horn, but am now playing a cheap palatino trumpet I bought on Ebay. I am gettting my lip back surprisingly quicker than I expected, but I have a problem with the trumpet. The third valve is not producing as clean a sound as the others. I can be playing a tune and as soon as I play a note that involves the third valve, it just sounds bad and unclean.
Is there anything I can do to fix it, should I take it to a repair shop, or should I put it down to it being a cheap trumpet and accept it?

If I were you, I would first clean the horn, since you bought (I assume) a pretty used trumpet. That usually solves a lot of problems. Also look for dents or obvious scrapes in the casings and in/on the valve; those are less noticeable and take more effort to fix, preferably through a specialist who fixes horns. Make sure that the actual valve was made for the horn, because it could be that the previous owner broke the original and got a replacement, which poses a lot of problems. Another possibility is that the casings and the slides, due to use and years of wear, got misaligned and need to be re-aligned.

Another way to look at this is the way you play. Make sure you use deep, energized breaths and do everything you can to not create tension. Breathe from the bottom of the stomach, not the throat. Good posture, firm embouchure, etc, etc. Those are common roadblocks that can be fixed with smart practice and more time on the horn.

You could also go to the local music shop that has instrument repair services and see what they can do. It might be costly and the service might not be fantastic but it will definitely get the job done. Or you could go the extra mile and talk to a horn maker. They often have the tools to repair horns and they are more willing to negotiate pricing (as well as the service too; they have an extensive knowledge and will make sure everything is perfect). In addition, if they will like doing business with you, maybe they can also give you a good deal in getting a new custom trumpet for an affordable price!

Hopefully this helps! Good luck!

belltrumpetplayer19

belltrumpetplayer19 thank you for the quick reply and very useful suggestions. I have already given it a good clean as that was what I first suspected.
I don't think it's my breathing, although after all this time it does need a lot of work.
I think I will find a repair shop nearby and have them check it out. If I can get myself back to somewhere as good as I used to be, then I might treat myself to a better trumpet.

<Added>

Update: Like a fool I was exploring all the complicated options, when I should have looked a little closer at the third valve slide and noticed it has a second spit valve... which is missing its cork. I trapped a little piece of rubber under the cap and it plays perfectly. :)

If you have a water key on your third slide, it might be a leak in the pad.

Something else you might try is this.....

http://www.thetrumpetblog.com/trumpet-valve-tightness-and-compression-issues/

Glad you found the problem, expat!!

All the best,
belltrumpetplayer19