Tube Checking!

I started last night working again on the RCA console and decided prior to a thorough cleaning, I would check all of the tubes for good gain, emission, shorts and quality.IMG_1584

I first draw out the map of all the tubes, place the correct tube designator and Tube number. This ensures i have the correct tube placement and that as I test i can mark off “bad” or “good” or “weak”. The weak might be good enough to get the amplifier working, but will need replacement for long term use.


Next I select a tube and and gently remove the glass electron masterpiece.


As you can see, some tubes are in great shape and others need some cleaning to be able to read the tube part number.


I have several resources to verify that the tube I have can be tested in the Knight Kit Tube tester that I have had for over 20 years.


If the tube is old enough I can use the scroll paper inside the KNIGHT “KG” 600 “B”  (Why they had the letters KGB in the nomenclature of the tester I have no idea!)  Kit test kit with the back lit scroll.


If not I have to turn to my other resource book with newer tubes. As the case for this very cool 6AL7 radio tuning tube. The tube lights the upper part of the glass on a grid that allows the user to “see” how in tune the radio station is getting. (I was very impressed as i have never see a working signal strength tube in working condition, and was surprised about how bright it really was.)


It was go time… setting the correct switches, turning to the correct voltage and socket selector I was ready to test!

IMG_1575 Even bright enough with the lights on!

IMG_1577Checking for the gain of the tube you can see the upper scale read “Good”

After a test of all tubes my failed list will be easy to acquire from E-Bay as I have already started the bidding process!

IMG_1574Here is a good picture of the Knight tube tester. It has been working perfect since the day i bought it!

Here are tubes I need to replace out of 14 tubes:

2- 6cg7

2- 6v6
1- 6x8a
1- 6av6
More soon!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s