[BULK] - [Amps] 2m Linear Amp Enquiry

[Ian White, G3SEK]

Steve Thompson wrote:
>> Search around for the W2GN design using a pair in parallel, it works a
>> treat. I modified the grid circuit to have separate bias control, so it
>> will work with unmatched tubes. Personally, I don't like link coupling -
>> it's possible to get false indications of optimum loading.
>Ooops - what I meant was - tuned link coupling. A variable untuned link 
>should give you monotonic loading adjustment, the same as a variable 
>series capacitor.
>

Should, but probably won't. Most link-coupled VHF/UHF amps suffer from 
chronic under-loading, because it's very difficult to make the link 
coupling tight enough to load the tube(s) correctly.

In contrast, capacitively-coupled VHF/UHF amps tune and load as easily 
as a pi-network.

The W2GN articles appear to be downloadable from:
http://www.newsvhf.com/w2gn.html
(I wasn't able to verify that - please can someone confirm?)


-- 
73 from Ian G3SEK         'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek