[R-390] R-390A 6C4 Mixers

[Jordan Arndt]

My goto replacement for 6C4s is the British CV133. I've tried 6100, 6135, 
6C4 and WA etc. versions from various mfgrs, and I find the CV133 quieter 
than the others in almost all cases. I've never had one die or short 
internally, which I can't say is the case for the other types.

I'm glad I built up a fair inventory of tubes for the gear I have back in 
the day. Lots of them came from the Glacier Hamfest which I used to frequent 
annually.

73...Jordan VE6ZT

----- Original Message ----- 
From: "Jacques Fortin" <jacques.f at videotron.ca>
To: "'Byron Tatum'" <bjtatum1 at att.net>; <r-390 at mailman.qth.net>
Sent: Saturday, June 29, 2024 7:47 PM
Subject: Re: [R-390] R-390A 6C4 Mixers


> The 6C4 is one of the first miniature tubes issued.
> The "double" 6C4 is a 12AU7.
> The 6100 is the Industrial number for a 6C4, which bears the 6189 number 
> in the double version.
> Both the 6C4 and the 6100 have 6.3V, 150mA filaments.
> The 6135 is a "ruggedized" version of the 6C4: 6.3V, 175mA filament, the 
> double version being a 5814.
> If the "A" suffix is added to any of those tube numbers, it means that the 
> heater warm-up time is controlled for use in series strings of filaments.
> The W suffix indicates a military spec. version, like the 6C4WA.
>
> However, stay away of the "dwarf" sized 6C4W branded Raytheon, because it 
> is not a "real" 6C4 and does not behave well as a frequency mixer compared 
> to the standard 6C4 variants.
>
> 73, Jacques, VE2JFE in Montreal