Does 3x TV Barlow work with extension tube?

[Space Cowboy]

I asked a similar question about the 2.5x tv powermate which does not increase magnification with extension and assumed that the 3x tv barlow does but having read the description on the tv website it states parfocal? The 3x tv has a long tube so does this mean 3x is its max?

[Merlin]

If you add an extension tube to a Barlow, it will increase the power, but it's taking the Barlow beyond its design intention.

[Space Cowboy]

Sorry I should have said this is for planetary imaging where extending barlows is common practise.

[JamesF]

Not sure that being parfocal will make a difference. If it weren't tipping down I could try it out and see what happens. Unfortunately the rain seems to have settled in for the evening

James

[Space Cowboy]

Thanks James yeah the weather has gone very wild.

[Space Cowboy]

Nobody out there used a 3x tv with extension??????

[Space Cowboy]

Problem solved. I've been directed to this graph which I failed to find myself D'oh!

http://www.televue.com/engine/TV3b_page.asp?id=52&Tab=_photo

[JamesF]

Well that's handy to know

James