SV: SV: [AMPS] Final..

[Ian White, G3SEK]

measures wrote:
>
>There is no way to have a good input match on 20m - 10m without tuning 
>out the grid reactance with a roller inductor and Bruene neutralization 
>bridge.  

There is at least one better way. Use a fixed 10m pi-network with the
input capacitance of the tube(s) acting as "C2". Make C1 = C2, so the
impedance transformation is 1:1. No tuning is required, and the network
becomes transparent at low frequencies so it doesn't even need to be
switched out.

Alpha use it on the 91/99b, but the idea is much older.

73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                          'In Practice' columnist for RadCom (RSGB)
                           http://www.ifwtech.demon.co.uk/g3sek

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