QRP Amp Circuit?

[WA2SQQ]

Working on a QRP project where the exciter gives me +15 dbm (31.6 mw). I'm looking for a simple circuit for an amp to get me to about  1.5-2W (31-33 dbm). Frequency range needs to be 1.8 to 30 mhz and capable of all modes, especially AM. A ready made amp would also be something I'd consider.

Any suggestions?

[W3GMS]

This may get you there.  I did notice some high frequency limits, but looking into the details I am sure would answer the question as to why that is.  Anyway the circuit looks pretty basic and has considerable gain so its at least something to look at for starters.

http://www.kitsandparts.com/qrp_amp2.php

73,
Joe GMS

[w4bfs]

push-pull stage is unbiased .... with bipolar transistors it will be in class C .... adding a bias ckt to it would likely be necessary to reduce distortion

[W3GMS]

push-pull stage is unbiased .... with bipolar transistors it will be in class C .... adding a bias ckt to it would likely be necessary to reduce distortion

On AM you could collector modulate it and leave the circuit as is without a problem.  Obviously it can't be used as is on SSB.   

"Capable of all modes, especially AM"  so maybe SSB is not a must. 

Joe GMS 

[kb3ouk]

push-pull stage is unbiased .... with bipolar transistors it will be in class C .... adding a bias ckt to it would likely be necessary to reduce distortion

A class C amp can be used as a linear amplifier for AM, there's several discussions about that on here.

[WA2SQQ]

Here's what I'm going to go with

http://www.qrpproject.de/UK/qrppa2008.html
57 Euro, delivered

[W3GMS]

I saw that one as well.  Would work well on SSB and AM since its linear.  A quick view of the Circuit seems like it will do what your looking to do. Not sure if your going to modulated your very low power driver or not or do it high level in the external amplifier.  Not great efficiency, but maybe that's not your objective.  I can't imagine 2W of AM, but to each his own!
       

[WBear2GCR]

One might take this sort of little amp and use it as a pre-driver for something like and EB-104??

[WA2SQQ]

So, here's my intention ...
I have a fairly stable Panasonic signal generator that covers up to 220 mhz. I want the QRP amp so I can use the generator as a QRP transmitter. I've tried externally modulating it and it sounds great. Whether I use it at 2W, or driving a second amp to a higher power, it will make for an interesting project, re-purposing a piece of test equipment not being used.