[Heathkit] Testing CRT's

[W. Harris]

If you had just a spot, then the sweep circuit isn't working and by leaving the spot on for any amount of time it burned the phosper on the screen and that is why it disappeared. 
Change the sweep generator tube V3, keep the intensity turned all the way down and only turn it up for a brief moment to check for operation. A scope would help make troubleshooting easier. 

Bill - K5MIL
http://radioremembered.org

> Message: 1
> Date: Mon, 20 Feb 2012 12:04:17 -0500
> From: "David C. Hallam" <dhallam at knology.net>
> Subject: [Heathkit] Testing CRT's
> To: Heathkit <heathkit at mailman.qth.net>
> Message-ID: <4F427D11.8080805 at knology.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> 
> Is there some way to test CRT's?  I have a SB-610 that I am trying to 
> get working.  I replaced paper and electrolytic capacitors, and a bunch 
> of resistors.  When I first turned it on I had a spot on the screen.  I 
> left it for a little while and when I came back the spot was gone.  I 
> have gone through the voltages and don't see anything that is way out of 
> whack.  I will admit that my HP 410C is not properly calibrated on the 
> HV range so all I can say about the voltages over 1000V is that they are 
> present and probably within a 100 volts or so of what they should be.
> 
> David
> KW4DH