20W WiFi Booster module for 2.4 GHz

    pe1chl

    The booster is made (advertised) for WLAN and not for FPV-Video - or did I miss something ? (It also includes a receive amplifier - not needed for FM-Video - thus I think this confirms that it is intended to be used in WLAN)

    Yes, the reverse-SMA is no problem I have an adapter from reverse SMA to N-Male and thus can connect the PA direct to the antenna.


    73 de Johannes

    • Official Post

    Hi Hans-Jochen,

    sorry for not getting back earlier.. I have a lot of things to take care right now, both qrl and for QO-100. Wouter Jan is right about everything.. and my unit is the same with the exception of the 24V label. Mine is running on 12V (PSU was included) and while it might run on 24V as well, I never tried. The empty spot is actually space for a circulator (you would need to find the correct type) and a 50 Ohm terminator next to it. But probably an external isolator is easier: PE1RKI

    An isolator is a circulator with a 50hm termination on one of the ports.

    It sends the signal from amplifier to antenna, but the reflected energy from the antenna (and other incoming signals) is sent to the termination resistor instead of to the amplifier.

    This protects the amplifier from bad SWR, but usually it is done to prevent intermodulation in the amplifier when strong local signals are present.

    • Official Post

    DK1MG isolators and circulators are very close to each other. Lets start with circulators: they have typically 3 ports arranged in a circle and RF can only go in one sense of direction: for example from port 1 to port 2, from 2 to 3, from 3 to 1.. Isolators now have a fixed 50 Ohm terminator at port 3. So assume the PA is at port 1 and the antenna at Port 2. Any reflected power from a mismatched antenna will go to port 3 instead of propagating back to port 1 (PA). Therefore the PA is protected from any mismatch caused by the antenna.

    Hi all,


    after the initial tests my 20W booster seems to be dead :(

    I am still testing if the first or final stage is affected, only 10 dB gain of the unit is left...


    Did someone else erperience similar issues?

    As the implemented amplifier chips are chinese parts, does someone got an idea where to get spare parts?

    (I know the downside of chinese modules...)


    vy 73 de

    Alex

    I had the same problem with mine, due to an oscillating driver ahead of the WIFI amp, I most likely blew the first stage. I ordered a replacement booster from the seller on Ali Express, and they kindly included a spare IC (YP2233W). IIRC it is a QFN package with an exposed ground pad, I have not yet had the courage to do the soldering (I expect it will need to be done on a hotplate).


    In order to protect the new PA from excess input power, I use a Minicircuits limiter at the input:

    https://www.minicircuits.com/W…rd.html?model=VLM-33-S%2B


    In combination with a power detector + Arduino + bargraph that provides an indication of drive power visible from the outside of my QO-100 outdoor unit.



    73,


    Wouter Jan PE4WJ

    Quote from DK4FT

    Did someone else erperience similar issues?

    Hello folks,


    I have the same issue with mine 20W PA module from AliExpress. Main symptom is if drive it with 10 dBm input, output power will about 100mW or 20dBm. I found that first stage module - YP2233W is faulty. Inductor on pin 16 (VCC1) was burned. Output voltages on DC-DC modules are normal - 5.2 and 28 Volts. I have tried to replace YP2233W with new one (ordered via Alibaba.com, 3$ for pcs) and replace inductor and it didn't help - new parts became faulty too and 5V DC-DC module going into short connection mode with 0V output. Really strange situation. For my conditions I don't need PA module with 10 dBm input, because mine BU-500 upconverter has output power about 1W (depends from input power on IF-input) so, I desoldered YP2233W with air gun and connect short lenght coax cable between input low pass filter and matching circuit before final stage transistor. And now have about 20W ouput power. That is my reserve module. Main module is a PA from SG-Lab - really great module. And in attachment you can find some infromation about final stage transistor YP07271815.


    Thank you for attention.

    Andrey, RK3DJW.