small valves and RE: OT

Allison ajp166 at
Sun Apr 24 18:44:13 CDT 2005

>Subject: Re: small valves and RE: OT
>   From: ard at (Tony Duell)
>   Date: Sun, 24 Apr 2005 22:02:54 +0100 (BST)
>     To: cctalk at
>1R5 = DK91 == Pentagrid changer
>1U5 = DAF92 == Detector and 1st audio
>1T4 = DF91 == IF amplifier
>3V5 isn't in the equivalents book, but 3V4 = DL94 == audio output
>And of course the 117Z4 is a rectifier with a 117V filament.

I have the RCA small tube handbook. I started as a bag carrying 
radio tech in the 70s and still fix stuff.  I started with tubes 
and recently built some tube radios for fun.  I have a pair of 
4CX250s itching for a 1kw input amp for 6M.  I haven't succumed
yet as I like to do radio stuff at QRP levels for the challenge.

>I am sure I don't need to warn you about this, but it's almost certainly 
>a live chassis set when run off the mains. 

I bought and keep a isolation transformer for just such repairs when 
needed back in 1969.  However that radio has a phenolic case thats 
in good shape and is therefor insulated. 

>> If it breaks I will.  Believe it or not I use it to listen to local station
>> for ball games.
>No why on eart hwould oyu want to do that???

The local station for RED SOX baseball is WEEI 850khz!  It's the best 
AM radio I have.  I have spares for the tubes.

>Oddly we can get Nuts and Volts and more usefully Circuit Cellar in shops 
>in the UK... IMHO Circuit Cellar has really gone down over the last year 
>or so, it seems to be just yet-another-microcontroller-circuit now, and 
>quite often the microcontroller picked doesn't seem to be the most 
>appropriate device .Oh well...

On rare occasions I see Elector, nice mag.  I tend to delve into fairly
serious stuff like DSP and UHF radio so the ARRL pub QEX is a favorite
alone with Trade rags like Electronics Design.  Around here there's about
30 linear feet of shelf allocated to linear and RF as well.  So I have 
oddities like Electronics Engineers casebook (ca1960) that has ED article
compilations about things like MIT/Lincoln TX2 and non computer stuff
as well. 


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