Low noise transistor and noise figure

[thanh]

which url has the price of transistors?

[mandat]

What do you think about low noise transistor arrays made by THAT Corporation.
THAT300 4xNPN
THAT320 4xPNP
THAT340 2xNPN
http://www.profusionplc.com

choose Products and THAT Corporation

[thanh]

mandat! thanks you very much!
I can't say anything about lownoise and fT .325Mhz is a ultra high frequency. fT of 2sc2240,2sc2362 and 2sc1815 is about 100Mhz
That 340 is very suite for building a symmetrical amp.But Beta is a problem, about 60-100 is very low . I have building amp with some discrete transistors .The low beta cause my failure. After my amp works for 3 days, these transistor no longer match each another -> increase the value of degenerationresistors .But I don't do like that. I remove fake 2sc2362Y/2sa1016Y and replace by good 2sc1815GR /2sa1015GR . I have not ever used array transistors so I dont' know what problem you will meet .

[TharneG]

I think this is a way to go low noise. The 'vikingcoupled MC/MM RIAA PREAMP' created by Jens Sommer www.remmos.dk.
But there is a lownoise dual n-fet which I can't find.
Anyone knows?

[peranders]

This was a 7 years old thread!

[AndrewT]

Hi Tharne,
is the first tube/valve operating as a cascode? i.e. common grid?

[TharneG]

Uppps -