Radioberry Preamp Board

Got a replacement for one of my orders where one of the AFT504 Transistors were broken out of the box.That was a super fast replacement without may questions.Can't test the board yet, but looks better than all my orders before No cold soldering, all pins are short and will not poke the radioberry.The white pins are my soldering. so don't take them as a reference for aursincs work.but, there is always a "but". the wires on the transformer are a bit long this time. i think that might cost just some milliwatts.All in all, i'm very happy with aursinc. meanwhile i build over ten devices and only one part was defective after recivement.To the customers:Hint 1: Use cooling. A fan, a coling plate, whatever.Hint 2: The AFT504 is made for 7.5v, so don't use 8v for longer time without a hard cooling. You will just miss some milliwatts on 7.5v.To the producer:Please rebuild and add a solution to cool the transistors.Example; Just a hole between the two transitors, so we can screw a coling plate on it.And/ or, made them easier to replace. The AFT504 isn't a long live product. It's qite hard to resolder them.The white pins are my soldering. s don't take them as a reference for aursincs work.old review for preamp v2 (end of april 2025):New version, new order and new quality ( preamp v2):it is a amazing little amplifier. got the radioberry setup running on 4 - 5 watts on all hf bands.sadly the board has still no hole to screw a cooling plate on the transistors. maybe available on version 3 of this board. :)Cooling plate issue fixed by parts out of the scrap box.old review for preamp v1:It is my second order. Found lot of cold soldering. On the other hand some of the solder points are so big, example sma, that they connect to radioberry board when mounted. first order was "okay". At all: check before mounting and fix it or send it back. whatever.

No me funcionó, no amplificó y no hay documentación al respecto, se devolvió el artículo.

I purchased the amp board before I noticed that it was not supposed to be compatible with the Pi4 board and required the Juice interface. I am glad I didn't see that in the description because I have it working perfectly with a Pi4, without any issues or modifications. The Pi4, Radioberry, and amplification board drive my Micro PA-50+ at 52 watts on 40m. I attached a couple of photos. I am using a voltage regulator to provide 8.4 volts to the amp board. I could use some help with the PTT interface. Anything I plug in automatically keys the Radioberry and amp.

The instructions that come with this aren't clear, mostly because half the directions apply to an earlier version of the product. However, once you get the thing running, it works really well. One of the nicest things over the base Radioberry, in addition to having enough power to be able to contact most stations you can hear, is the built-in T/R relay that lets you use a single antenna for transmit and receive. You definitely will need to use this in conjunction with a band pass filter, since there are tons of harmonics on the amplified signal (not a knock against the product, but something to be aware of).I have been able to make FT8 contacts on every continent with this (previously, my most distant contact was about 2000 miles), so this little amplifier makes a big difference. My biggest issue is that I ran through all the HF bands on WSPR, and after about 20 minutes of near continuous transmitting, the amplifier transistors gave out. I was able to replace them fairly easily and get it working again, but I definitely wouldn't recommend this for near continuous use. Once I replaced the transistors, I backed the bias setting off a little bit in the hopes that it won't overload this time. With better documentation (and a schematic diagram), I'd probably rate this four stars, but like the Radioberry project in general, this isn't a consumer appliance and you'll want to have some in-depth electronics and radio knowledge to really make use of this board.I will note that this works fine with a Radioberry on a Pi 4, and I did not have to use the Juice board and attach it via USB.

Excellent, delivery beyond expectations