Short Range on rx

[Winger]

Bought a small batch of vtg rxs off fleabay and although they work the range is only a few feet. On one I even soldered on a new antenna just to be sure. The txs I am using have been range tested and are fully functional. I think I have about 4 like this. Any ideas/suggestions?

[urban hype]

The receiver antenna has to be the correct length. If not the short range is the result. The antenna wire is pretty easy to change with some basic soldering skills. Which receivers do you have?