nrf905 433 to 915 rf output

[Jack]

I purchased a bunch of ptr8000 boards off ebay from china to do some testing of the nrf905 without realizing they were setup for 433mhz, and I need 915mhz. Looking at the datasheet reference design, it appears there are just a few components that are different for 915 operation. I am wondering if I should replace these components on my cheap boards so it will work at 915mhz. How much worse will these boards work at 915mhz with the 433mhz components?

I had a fcc approved product for the nrf2401 and now I need 915mhz and like the simpler nrf905 compared to the rfm96.

[Wojtek]

What kind of answer do you expect, basing on info "few" "different" components on "cheap board"? I would say it may work a bit worse. Assuming that "a bit" MAY also mean that range will drop to few centimeters.

[bjorn-spockeli]

Although, there are only a couple of components that would need replacement you still have the antenna. The antenna on your module has probably been designed for 433MHz with a loop antenna as specified in the Product Specification. In order to operate the nRF905 at 915MHz you need a quarter monopole antenna, as described in our nWP-009 whitepaper. My recommendation would be to buy boards designed to operate at 915MHz

[Jack]

I have not found nrf905 boards designed for 915mhz, other than $330 dev kit.
Looks like I will just go with the rfw69 which they are $5 915mhz boards available.