[ARC5] VHF Set Sensitivity

[Kenneth G. Gordon]

On 30 Dec 2008 at 0:00, David Stinson wrote:

> after alignment, the set's sensitivity for minimum comms
> is about 3 microvolts.

That is about right for the time period, IIRC.

>  For a "full quieting" signal,
> it's more like 6 or 7 microvolts.

Again, about right for the time period, as I remember it.

What does the manual say it should be?

>  I'd like to test 
> these tubes before going further.  Does anyone have 
> a set-up for the TV-7 that will do 9002 and 9003?

The 9002 is a "UHF" triode, base diagram, 7BS, while the 
9003 is a remote-cutoff pentode, base diagram 7BD.

Characteristics for both tubes are here:

http://hereford.ampr.org/Tube.php

and substitutions are here:

http://www.nostalgiaair.org/tubes/

However, there are no substitutes listed for either tube.

The NJ7P site has links to other tube data sites. Franks's is 
one of the best. He has PDFs of original tube 
manufacturers data.

Perhaps from one of those you could glean enough 
information to figure out how to test them, but I am betting 
they are all right.

I know some tube testers (my TV-2 for instance) has a way 
of testing unknown tubes that works fairly well.

Ken Gordon W7EKB