Newby questions - please suffer me - planning a new uTracer

[David Pidwerbecki]

I have been reading up on the uTracer for a number of years and am getting "close" to purchasing a kit to make one.  I will *eventually* like to get a uTracer 6.   I looked at Ronald's great website and see all of the great ways people have made their boxes for the sockets and pin set ups.

Has anyone used an old tube tester for the case and sockets/pin allocation mechanism?  I'm thinking of finding a junk a TV-7 or Eico 666/667, etc. and utilizing components of the tester as the starting point for a uTracer.    I am thinking I can make a new panel out of aluminum sheet metal but add the uTracer required features and utilize the vintage switches and sockets.

Has anyone ever done this before and if so, how did it turn out?   Is the wiring so complex on these testers that I'll be chasing oscillations, etc.?   I think that the switches should be able to handle the potentials - especially for the uTracer 3+ (but will it work for the uTracer 6?).

Thanks for your thoughts.

[David Pidwerbecki]

I'm sorry, I followed up on Ronald's web site and found the TV-7 switch/socket set used...so I guess it can be done.  I will probably use a custom panel with labels.  The Eico 666/667 switch and socket set looks inviting as well.   Has anyone used these?

I really like these switch sets for it makes it difficult to connect the different potentials being delivered to the socket pins.

Sorry for the confusion.

[Martin Manning]

What kinds of tubes are you planning on testing? 99% of my needs are covered by octal (8), noval (9), and the very occasional 7-pin, so those are the only sockets I have on my tracer. Using a patch cord setup I can connect to anything unusual that might come along with clip leads. I have tested sub-miniature and Compactron (12 pin) tubes that way, and traced numerous things besides vacuum tubes. 

[David Pidwerbecki]

I'm into restoring antique radios, TV's and tube test equipment.   I sort of have a tube testing thing going on, and I have no real "need" for a curve tracer - but I am interested in the curves.  I have a bunch of tube testers and am interested in comparing the values across the different testers.  One of my interests is making solid state replicas for 83, 5Y3, 5U4, 80, etc. tubes out of passive components.   I need to be able to test 4 pin, 5 pin, 6 pin, 7 pin mini, larger 7 pin, Octal, Loctal, 9 pin mini and 9 pin magnovel, etc.   I actually run across all of these in my work.   

You are correct though, maybe the patch cords is the best way to connect power to the tube components.   One just needs to remember that the cathode and suppressor are often connected inside the tube.   I do like the idea of having a set of clip leads for tubes where you don't have a socket (I have run into this with compactrons).   Patch cords are the most straight forward build.

[Martin Manning]

You might see just about anything then. For receiving tubes the uT3+ is more than adequate voltage wise, and when modified for 600 mA max current per Ronald's recommendations, it is a very capable tester and tracer. In any case, seeing the curves is much more informative than checking a single operating point. You are probably aware that most vintage testers do not use anything like the 400V and current the uT3+ is capable of, which is great, but you might be going well beyond the levels formerly seen by your donor socket array. I enjoy seeing the widely varied examples of tracers on Ronald's site, but I'm still very happy with my compact solution using patch cords for the tracer itself, and using two small 30V DC bench supplies for power.

[Martin Manning]

Here's an example of a setup using a small breadboard to trace a subminiature tube. It's sitting on top of the DUT socket pin jacks, which are arranged in a circular pattern between the six uT terminals (ASG left, HHK on the right). The ferrite on the grid lead was required to suppress oscillation.

[David Pidwerbecki]

Thanks so much.

I think I'll get the uTracer 3+ and add an external supply for the filament.   I don't work on high power transmitting tubes.  All of my Ham stuff is software based/IC stuff.  

I do run into 117V filaments (rarely).   I looked at the supplies recommended by Ronald but these are DC-DC supplies that run off of the laptop 19V supply.   For radio, 35V and 50V tubes are common.   Does anyone have a recommendation for a panel mounted supply that will work for this purpose besides an autotransformer and an AC volt meter?   I'm thinking of a DC out power panel mounted supply that can go to 120V (ish) DC from 120V AC source or a 19V DC source. 

I'll read up on the uTracer 3+ and the current recommended build.   For instance, I don't think I ever use run into tubes that have a positive grid.

Dave