View Single Post
  #3   Report Post  
Posted to rec.audio.tubes
[email protected] themend@gmail.com is offline
external usenet poster
 
Posts: 18
Default Restoring a TV-7/U Tube Tester

Hi again,

So, I was able to get to RadioShack in time, but much to my dismay, the one closest to me was in the process of packing away all their items to be shipped to other stores. Luckily, the other store was only a couple miles away, and I was able to pick up a pair of IN4001.

Much like in the Sherwood project, I soldered these diodes to a terminal strip, and the result can be seen he

https://www.dropbox.com/s/wmtt94daib...iode_Strip.jpg

One terminal has a positive facing diode, the other a negative, and the mounting lug has the other two ends of those diodes.

To install this, I first had to de-solder and clean the three terminals in the TV7 that these diodes connect to. In order to get access to the two terminals on the push-button strip, I had to first unscrew its two mounting screws from the face plate. This gave me enough room to work after pushing some wires aside.

After de-soldering and cleaning the connection on the rotary knob, I stripped back and threaded the original wire through the hole in the knob terminal and through the hole in the diode strip mounting lug. I then clamped it in placed, pulled the connection tight, and soldered it in place.

After preparing the connections on the button strip, I soldered a red wire to the positive connection, a green wire to the negative (I'm out of black at the moment) and left about 3" of wire on each sticking out as I re-attached the buttons to the face plate. I then gently bent the diode strip into place and connected the positive and negative leads.

The connections can be seen he

https://www.dropbox.com/s/iuv84wy7lx...onnections.jpg

The red circle shows where the positive diode will connect, the black circle shows the negative connection, and the blue circle shows where you solder the mounting lug of the diode strip, and the common connections of the two diodes.

After re-mounting the buttons and soldering on the positive and negative wires, the finished diode installation looks like this:

https://www.dropbox.com/s/4youxfuerx..._Installed.jpg

The whole thing fits in there quite nicely and after checking the diodes with a meter to make sure they survived the heat of soldering, I was ready to fire it up.

The next step is now attempting a line calibration, and I will get into that in my next post.

Cheers,

-forkinthesocket