[Boatanchors] NEED TUBE INFO

[Brian A Clarke]

Hi Dave,

In the words of 'Yes, Prime minister', you are brave, ie, wrong.

The 280 is the 5 V development of the 213 which was the 2.35 V heater
dual diode rectifier.

All the authorities I have looked up say that the 280 is equivalent to the
80.
However, that said, not all type 80 valves are equal - some manufacturers
produced 80s with larger plate area to handle the increased demands
placed on the rectifier.

73 de Brian, VK2GCE

----- Original Message ----- 
From: "David Hollander" <n7rk at cox.net>
To: "Bob Kulow" <kulow at epix.net>
Cc: "BOATANCHORS" <boatanchors at mailman.qth.net>; "FLBA"
<FLBOATANCHORS at YAHOOGROUPS.COM>
Sent: Wednesday, July 18, 2007 12:03 PM
Subject: Re: [Boatanchors] NEED TUBE INFO


> Hi Bob -
>
> The 280 is NOT the same as an 80. It is a rectifier with a 2.5 volt
> filament. The rest of the specs are the same or very similar to the 80
> rectifier.
>
> 280's are much harder to find and considerably more expensive so don't
> test it as an 80.
>
> Use the 80 settings on your TV-7 with the filament set to 2.5 volts.
>
> It is used in the early national doghouse power supplies on the radios
> that have the 2.5 volt filament tubes and it is also used in many lat
> 1920's and early 1930's broadcast receivers.
>
> Hope that helps.
>
> 73,
>
> Dave N7RK