Anyone tried a SPB-2026Z amp?

[G3GJA]

I bought a couple of the RFMD SPB-2026Z devices and matching PCBs from here: http://www.ebay.co.uk/itm/RFMD-0-7-2-2G ... 0391561412 recently in the hope that they would make a good driver for the 23cm DigiLite. There's more info for 23cm use here: http://s3.amazonaws.com/zanran_storage/ ... 722956.pdf

They are supposed to have good linearity as they're designed for cellular applications with a P1dB of 25dBm and a gain of around 13dB. However, while the one I built up draws the right quiescent current and if driven hard enough the current can reach almost 1A, I'm only getting around 3dB power gain.

I've tried a different choke in the output pin supply and made sure that the ouput circuit is not open or s/c to ground but I can't understand why I can't get all that supply current converted to RF.

Ideas anyone?

[G0KTD]

Amp

2watt amp.jpg (305.61 KiB) Viewed 4906 times

almost 2 watts

2 Watts.jpg (285.02 KiB) Viewed 4906 times

I have one giving 2Watts out it was put together by G4KLB Colin as is was a bit small for me to do he built it with a hot air gun on the device as this is a bit tricky to do with a soldering iron
The Scart Group is working on a design for one as well look at GB3SQ NET ON SUNDAY


Keith G0KTD

[w0fms]

Thanks for the heads up on those devices. I'll have to pick a couple up. On this side of the pond, they are dirt cheap!

They would also work nicely for 902-928 MHz here in the states..

Fred W0FMS