Adapter to screw 3x TV lens element to ZWO ADC?

[Space Cowboy]

Is there an adapter to screw my 3x TV lens element into the filter thread on the end of my ZWO ADC? 

Trying to reduce focal length by removing the 3x TV tube.

[Louis D]

Not that I've ever heard of.  You could try taking it to a local machinist to have the threads measured and have one made for you.

Alternatively, look for a vintage Meade series 4000 140 APO barlow.  Its optical nosepiece has standard filter threads.  It normally operates at 2.4x, not 2x as advertised.  In my Arcturus BV, it operates at 3x.  Optically, I've compared the Meade to my TV 2x Barlow, and I can't see any difference between them.  Both are Japanese made.  I've got 3 copies that I use for various purposes, and have never paid more than $50 for one.

[Space Cowboy]

3 hours ago, Louis D said:

Not that I've ever heard of.  You could try taking it to a local machinist to have the threads measured and have one made for you.

Alternatively, look for a vintage Meade series 4000 140 APO barlow.  Its optical nosepiece has standard filter threads.  It normally operates at 2.4x, not 2x as advertised.  In my Arcturus BV, it operates at 3x.  Optically, I've compared the Meade to my TV 2x Barlow, and I can't see any difference between them.  Both are Japanese made.  I've got 3 copies that I use for various purposes, and have never paid more than $50 for one.

Thanks Louis 👍