Ratio Transformer Gertsch RatioTran RT-18

[saturation]

A typical Gertsch, usually rated at 0.35 x frequency or < = 350V rms whichever is reached first, means on mains you'll need a variac to reduce the voltage.  You'll find the limits on a label on the unit.

[JuiceKing]

A typical Gertsch, usually rated at 0.35 x frequency or < = 350V rms whichever is reached first, means on mains you'll need a variac to reduce the voltage.  You'll find the limits on a label on the unit.

Yes, this is the usual rating.

There are also high-voltage variants, with a 2.5 x frequency rating  but I've never seen one in a standalone configuration. They are paired with the typical 0.35 x frequency rated RT inside the big 1000 and 1009 dual-RT boxes. Two RTs in one.

Let me guess that two RTs will not be enough for you.     

I like your suggestion of seeking a stable signal source from a digital player, and I'll give it a try.

[amspire]

I've heard that RTs were once used for testing avionics, but that they are obsolete for that application today and that's why the RT-5 types are so plentiful and inexpensive. I don't actually know what tests were done, and am curious to know more, so do share what you discover.

I Did a post on  Sperry avionics servo calibrator containing a RT:

https://www.eevblog.com/forum/reviews/sperry-ratio-potentiometer-teardown/msg74752/#msg74752.

Richard

[saturation]

That's a very good thread, and thanks for linking!  I forgot all about it, and you also describe good purposes for using a Ratio Tran.  The other thread is good additional information to anyone on this thread.

There are several avionics calibrators on eBay that pop up now and then with embedded RTs; while they can come cheap, they tend to be true "boat anchors."  Gertsch stand alone units are often ~ 10# and encased in sheet steel.

If you find models that have external fuse mounts then unless its been abused, its unlikely to have been opened since sealed by the factory.  One thing to ponder with its age is if prior owners could have contaminated or abused the unobtanium switches.

I've heard that RTs were once used for testing avionics, but that they are obsolete for that application today and that's why the RT-5 types are so plentiful and inexpensive. I don't actually know what tests were done, and am curious to know more, so do share what you discover.

I Did a post on  Sperry avionics servo calibrator containing a RT:

https://www.eevblog.com/forum/reviews/sperry-ratio-potentiometer-teardown/msg74752/#msg74752.

Richard

[SilverSolder]

Sorry to re-awaken a slumbering thread...  but does anyone know where I might get hold of a manual and/or a spec sheet for a Gertsch RatioTran RT-18 ?

[amspire]

I have the PDF manual for the RT-5. Do not have one for the RT-18.

Richard