Under-performance of EP-AB003 WiFi amplifier

Hello Chris,

Your image is showing the OUTPUT site of the device.

The "part" of interest switches between the RX and the TX-branche of the PA. If you want to use the PA only for TX (e.g. QO-100) then you can just bridge the part and get about one additional dB :-).

If you also need to RX via the PA this modifiaction is not suitable for you.

The "wire" goes from the marked PIN to the marked solder joint of the capacitor (not to the pin of the IC - the image is not very good thus someone could be miss leaded - so I repeat: solder to the marked point of the capacitor !!).

73 de Johannes

That's about an average gain for those amplifiers. There is nothing wrong with it I'm afraid.

As mentioned by Johannes above, you can bridge the input and output switches to get a dB and a bit more gain.

Most people run them with closer to 23dBm in to get full output. These amps get a bit of a bad press for splatter, but in reality they will run pretty cleanly up to 3W out - the difficulty is that people are using preamps with a P1db of 20dBm as those are the only easily available ones from ebay etc.

I guess they may vary - but I have two and they measured 11.6dB and 12.4dB at around 2W out.

The articles and postings I've read tend to agree with this - 12dB is the most common reported and the highest I've seen was 14dB, but that was with the supply mod and I think the link mods too.

I have a 4W model which gave a bit more gain, but less output.

G4SDG Hi Chris.
I have the same gain as you, just a little over 12dB, but have between 2.5W and 3W output when driven from 170mW. - comfortable level for SSB with a 0.8m dish.
I think the 'gain' quoted on the seller's websites includes the gain of the antenna !

At 3W the output is clean but my driver is a BU500 converter which uses this PA chip.

RFPA5208 Data - Qorvo

73 David

What about powering this PA with more than 12 Volts?

Is it spending more power out?

vy 73

Detlef

DD1EG

Hello Detlef,

more than 12V is only more stress for the internal DC-DC-transformer of the PA. The applied 12V are internaly regulated to 6V.

Thus if you really think about higher voltage:

First look at the datasheet of the power transistor - especially the voltage specification. And if there is enough headroom, then you have to change the internal DC-DC-converter or inject the higher voltage direct.

But I think HB9SKA is right....nobody will recongnice a difference between 3,8W and 4,3W So it's not worth the effort.

73 de Johannes

Hi,

oh i did not know that there is a regulator to 6V. In that case it does not make sense.

Thanks,

73 de Detlef

Here is a link with some information about those WIFI amps. It's in Russian. So google translate is probably necessary.

http://www.ra3apw.ru/qo-100/qo-100-stc7031_appn2/

Works also fine by me, but a little more Power where nice for my portable Equipment - 45cm Offset Dish.

Checked again the Internet and found this one:

FMS2031-001 10W GaAs WIDEBAND SPDT SWITCH

http://www.farnell.com/datasheets/388129.pdf

73 de Tom

Yes i know is the Rx/Tx Switch on the Output side. G4SDG searching for the Info on start of this treat.

Max 0,6 dB loss according to Data sheet. That is not the reason for the poor Performance.