Hi all.
Now that I've got my WSPR transmitter legal with regards to harmonics, I'm looking for an amplifier to take the 10dBm, 10mW up to a max of 37dBm, 5watts but I'll settle for 33dBm, 2watts. Has anyone got a circuit or know of a kit I can use. I've got a couple of BS170 in my junk box but I'll use anything that can be sourced.
Many thanks
Colin MM5AGM

I bought a broad band amp module on ebay for a few £, with some home made LPFs.
You will need LPFs using 170s too.

There are quite a few kits that use 170s, maybe have a look at their circuits and adapt one.

Thanks for replying.
My wspr beacon is fully filtered from 40M to 10M. Better than -43dBc.
Can you remember what one you bought? I bought an Akozon RF Power Amplifier, RF Broadband Amplifier 1-930MHz 2W RF Broadband Power Amplifier Module for Radio Transmission HF VHF from Amazon but it seems to be faulty - it attenuates my input signal by 30dBm. That's made me wary of buying any other.
I've spent days on the internet looking for something but no go so far.
Colin

The filters need to be on the output of the amplifier.

Sounds like you bought one the same as mine, has a black heatsink on it? I can't remember where I bought it apart from it being ebay.

I have another WSPR setup that has stacked boards, and one of the layers was a PA board, it got its time and location from a GPS board.
I can't remember if the PA board was one I made or if it was part of the kit. It was fully stand alone, if it is of interest I will try and find it after the new year and give more details.

Just went and had a quick look.

This is the stacked board one I mentioned https://qrp-labs.com/ultimate3/u3s.html

Can't find the completed one (could well have sent it overseas already) but I did find another complete kit, so at least I know what it was, and it has jogged my memory.

These are the kits I bought, with all the filters etc., and I bought one of their 10W PAs, but didn't use it, I made my own PCB for a slightly modified version of their 5W PA https://qrp-labs.com/pa.html

I do also have one of their 5W kits in the box with the unbuilt kit, I can't remember why I didn't use it, maybe it just didn't fit into the box I wanted to use.

Have a look at the manuals for those two amps, the circuits could give you ideas, they also have nice filter kits and a filter switching board that works with the kit.

They are not expensive either