[GreenKeys] [OT] - First Tube Equipment Restoration Project

[Keith Lueck]

 Yup, Jeff's right.  I have half a dozen Tektronix 500-series 'scopes (yes, there's something very wrong with me <g>), and I restored a 1935 Sparton table top radio, and a 40's vintage National SW receiver.  Very rarely are tubes the problem.  Paper / wax caps are definitely the enemy, followed by electrolytics, and then carbon comp resistors that have drifted out of their tolerance.  Altering the Sparton's filament circuit to eliminate its "curtain scorcher" power cord was a bit of a challenge. I'm sure the Heathkit 'scope uses a transformer for the filament and plate supplies, so, you shouldn't have to worry about that.  
Once you are ready to fire it up, a useful technique is to put a 60 W light bulb in series with the hot side of the AC line to act as a ballast - if something is shorted, the bulb will limit the fault current.   Good luck!  


    On Monday, June 10, 2019, 9:59:08 AM CDT, Jeffrey Angus <jdangus at att.net> wrote:  
 
 On 6/10/19 9:16 AM, mwillega wrote:
> Do I seek out  or build a tube tester or just test in circuit.
Test in circuit is the easiest.
> Anything else that I should look out for, besides the usual
> concerns about high voltages on the chassis, and old degraded
> components.
1st, find a schematic for it.
2nd, take your time and replace ALL of the electrolytic and
paper capacitors. ONE at a time.

Now you can turn it on and see what it does.

I repair vintage tube radios and test gear, so feel free to
pester me with all your questions.

What model Heathkit scope do you have?

-- 
"I am a river to my people."
Jeff-1.0
WA6FWI
www.foxsmercantile.com

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