onelinkmore 12dBi 433MHz Antenna High Gain Radio Antenna SMA Male Connector Omni-Directional Antenna Wireless Antenna for Wireless Sensor Network Router Modem Pack of 2

Empezando, S11 a 433MHz es más de -5dB. En el caso particular de las antenas adquiridas, la frecuencia de resonancia de las antenas parece estar desviada al menos 20MHz. S11 a 433MHz es más de -5dB. En el caso muy particular de las antenas que compre, la frecuencia de resonancia de una antena esta en 464MHz y la otra en 453MHz. Agregar cables SMA no es recomendable, ya que la frecuencia de resonancia cambia aleatoriamente a valores que no pueden ser controlados a menos que también se diseñe un circuito de acoplamiento, lo que incrementa el costo que se buscaba ahorrar.

These work very well but are rather large.

I got these because my router's antenna snapped off by accident during a move. Luckily the weak point was at the hinge and it didn't damage the antenna jack itself. It was easy to screw in the replacement and bing bang boom, Bob's your uncle. No issues.

I purchased 2 of these antennas and put them on a vector analyzer that showed neither one is resonant near 433 MHz. Instead, the lowest SWR was achieved near 480 MHz, therefore they are not useful for transmitting in the 433 MHz ISM band.

Sadly these didn't increase my connection to the wifi when I twisted these onto my desktops wifi card. I was hoping they would help at least a bit. Even tried both 2.4 ghz and 5 ghz wifi access points to see if theres a difference. Sadly none in comparison to much smaller antennas.