Radioberry Preamp Board V2, A Addition to Turn The Radioberry into a Small QRP Radio, HF Power Output 3W-5W for HF Amplification (10W-100W PA), for Raspberry pi 4,4b

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.

Very nice product. BUT the instruction are not good, as well as the unreachable link to download the test file. I already connected it to my Radio berry, with the raspberry pi-4. and it works fine

Not what I expected. I assumed this would be a plug-n-play R-Pi device, however it requires soldering on a super amall level that requires a very steady hand and small solder/tip. Buyer beware,

You need to digest a lot of specific information to make it work. Do not expect much.

Tutto ok grazie

It looks well built but I could not get the radioberry to work. I ended up returning this because it's pretty expensive for what it is. There are much better options out there for a qrp sdr.

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.

Once you get the thing running, it works really well. The vendor has updated the documentation since my original review, so it's better now. 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, as this is common to amplifiers in general, 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. 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. **Update: I've been in contact with AURSINC's customer support following my original review and I must say they have been extremely helpful. They have updated the documentation with additional information and it now includes a schematic diagram. Based on conversation with them and my own experience, the board works perfectly fine for shorter digital mode transmissions like FT8 (I have had several multiple-hour FT8 sessions with the bias at 2.7v without failure), but the bias voltage must be backed off to a lower voltage (they recommended 2.4-2.5v as a safe level) if you're going to do longer periods of continuous digital transmission. In my own experience, the amplifier transistors will fail after 5 to 10 WSPR transmissions, even if those transmissions are several minutes apart. I can get a WSPR signal out around the world without the amplifier in any case, so I'm not overly worried about this, but it's good to know that it's a limitation.

仕様、動作説明が少ないので事前学習が大切ですね。

Don’t waste your money on this product, it doesn’t work, I have connected it to the RadioBerry but can not get any power from the pre amp.

Not sure why it is doing this, with a different software (sparksdr) it appears to work occasionally but then completely stops randomly. The waterfall for pihpsdr is just this weird rainbow and does not seem to show any frequency reception whatsoever. I have tried to reinstall the software and even the pi OS several times. Still just this screwed up screen. I'm at a loss, literally short the money i paid for this. If someone can explain what is wrong and if it is fixable then I can change this review but I followed the online step by step tutorial and this is all I get. No reception, dead waterfall. Not happy.