PA's for 23cms Digilites?

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Basil
Posts: 381
Joined: Tue Sep 10, 2013 7:28 pm

PA's for 23cms Digilites?

Post by Basil » Tue Nov 05, 2013 12:03 pm

What are my choices for PA's for the Digilites? Preferably commercially made, but would consider a kit if known to be 100% OK. I do actually have some nice
big heat sinks, and 12 or 50V high current supplies, come to think of it. Thanks.
Best regards,

Chris, 2E0ILY in rural Shropshire.

It was a lot more fun being 20 in the 70's than being 70 in the 20's

g8ajn
Posts: 45
Joined: Sun Mar 16, 2008 1:59 pm

Re: PA's for 23cms Digilites?

Post by g8ajn » Tue Nov 05, 2013 6:51 pm

The output from the DigiLite modulator section is very low, typically 1 or 2mW, and one or two stages of amplification will be required to get to the 150-200mW input required by the RA18H output brick (500mW for dual version). A MMIC followed by a more powerful amplifying device such as RF2126 is a typical arrangement, some lower power bricks or even an under-driven RA18H brick can be used as a driver.(with suitable attenuation). It is important not to overdrive the input to the RA18H, not only to avoid unwanted distortion of the ultra-linear digital signal, but also to avoid permanent damage to the first stage of the brick. There are a number of Ebay shops supplying suitable kits, search for 'rf amplifier'. MiniKits in Australia have a useful collection of amplifier kits. A browse through the BATC Forum will also reveal a number of useful links If you are handy with homebrew pcbs you might try this design from 9H1LO.
Copied from http://www.g8ajn.tv.
Dave G8AJN

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