15-10-2018, 21:36
(14-10-2018, 23:00)Werk_AG Wrote: Hi engolling
From my experience with those modules, increasing voltage above 9V brings more problems than solutions, specially frequency shifting. Also they don't last so much when powered by 12V.
When I saw the metal box you have designed for housing the two TX units one thing has bring to my mind: he will have to use an coaxial extension between the SMA connector on the TX board connector and the antenna. Be careful with this approach, attaching the antenna directly to SMA connector on the TX board is always the best.
If you would like to experiment with a different transmitter module, try this one:
H34C 433Mhz ASK MINI RF Wireless Transmitter Module
The pinout isn't compatible with the TX board, but it isn't difficult to adapt. I'm experimenting these small modules since months, and found they are more stable in terms of frequency shifting.
Hello Werk,
thank you for your feedback.
That was the main reason why I was asking, if someone has experience in supplying the transmitter with more power.
Concerning the box and the antenna - i don't see those problems in using a coaxial cable as extension. In using a good quality wire the attenuation should me very small. Im my opinion it is much better to use a longer coax wire to bring the antenna in a better position, because signal loss in the wire is ways less then in the air. In addition the wave impedance of TX Module, Wire and Antenna have to be matched.
The H34C module also does not have more transmission power, but as you say, the frequency maybe more stable.
What do you think about this transmitter:
https://www.aliexpress.com/item/433MHz-5...8e5bb6f171
Should have a lot of power and might also be compatible because it is using amplitude shift keying.
I have some friends who have the equipment to check frequency, impedance and transmission power of the modules, antennas and cables at work and I could give some stuff to them to make some measurements but I always have to select my stuff well, because they also don't have infinite time at work
Best regards,
engolling