Vixen Porta II Owners

[N1 (Mirko)]

Hi, not sure if this is correctly placed here (as opposed to beginners), but some contemporary wisdom would be appreciated on the Vixen Porta II.

- where in OZ or NZ did you buy it,
- is it available on its own (in which case, does it connect to 3/8" thread)
or with tripod only?

while some digging could possibly answer the above, the following is a little harder to establish:

- how good are the slo mo controls & what's the ergonomics like? Does it get tiring during extended observing & tracking?

- how well does it stand up to windy conditions?

- what is the heaviest & longest OTA (refractor) it could comfortably carry?

- will the longest OTA above still reach zenith?

- how long does it take to settle down (and with what scope) after being touched?

Looking for a potential replacement for my Manfrotto 410 Junior head for astro use (the geared head is magnificent for just about everything else so will definitely be kept but the knobs are a bit stiff and I suspect the head might introduce some movement as not designed for astro).

I'd like to comfortably use powers up to 250x, and not be reduced to sub-100x when there is a bit of a breeze going.

Thanks very much

[dannat (Daniel)]

it does connect with 3/8" thread -can be bought from peter Tan in HK

can it carry long refractors -not really, specs say 8kg - maybe 6 for a CAT--holds up better without the Al tripod..dampening can take a little while few secs

[LewisM]

I think Steve is the ONLY Aus supplier now: http://myastroshop.com.au/products/d...p?id=MAS-033A4

Steve says 5kg load.

I have used the GSO/Bintel copy - it's carp. Everything had a habit of loosening without any input, and it tended to slip... and that was with a Skywatcher ED80 and a Tak FS60!!!!! (separately, not together) The Vixen version is a LOT smoother and steadier. The GSO/Bintel copy is a fair bit cheaper though, but cheap comes at a price.

[glend (Glen)]

I have had my Vixen Porta II for a couple of years. I bought it online from a US supplier when it was on sale ( think I paid $199USD for it, back when the AUD was above the USD) - and frankly Steve's price could not complete even with shipping. I also have a guide handle for it which is very useful, which I bought direct from the Japan maker but it's also available here:

http://agenaastro.com/kokusai-kohki-...-ii-mount.html

I have the JMI Train-n-Track motors on my Porta II, and this means no fiddling around with the slow mo cable knobs:

http://www.optcorp.com/vixen-tnt-tra...ii-mounts.html

I have used just about all my scopes on it. It has a Vixen dovetail mount of course. The Az and Alt bearings are adjustable and can be tightened up. The mount is pretty good at holding a scope at a particular spot but still easy to move against the clutches.

I have a ES ED80 Triplet APO which I use on it as a grab and go setup. I have also had 100mm short and long (f9) refractors on it when I owned them, and it didn't even know they were there. I used it to test the setup of the 127mm iStar R30 f12 that I built, and at 1467mm focal length it could still be used but trying to work around the zenith meant avoiding one leg. No clearance issues with shorter focal lengths. The iStar 127 is pretty heavy for the PortaII (at around 9kg all up) but it handled it ok, but balance becomes a tricky thing.

The JMI motor drives are easy to use, and run off 12V (from the supplied battery pack or from an external supply). You just find your target and then adjust the Alt and Az motor control levers to keep your target object in the field of view - easy to use. You can also push the fast buttons to slew if you want, or to catch an object that has drifted off for any reason. Much easier than trying to spin those control stalks. The JMI Train-n-track cost me about $250USD at parity.

I have thought of selling the mount, JMI Train-n track and handle from time to time but its just so handy to have and use that I can't let go of it. Even though I am mainly imaging these days it still gets used for visual work, and quick looks at comets, ecilpses, etc.
Hope that helps.

[LewisM]

http://myastroshop.com.au/products/d...sp?id=MAS-022L

Should be a fine system with the Porta II

[Tinderboxsky (Steve)]

I too have had my Porta Mount 2 for a number of years, am thoroughly happy with it and will likely keep it long term. It excels as an easy to use, highly portable mount.
I have used it successfully with a 140mm f5.8 refractor weighing 9kg all up. At this level the tripod is the weakness - I use it on a pier, or a heavier tripod if travelling with a long heavy scope. Vibration and/or wind does become a problem above 100x with larger scopes on the mount and supplied tripod. This is mostly solved with a sturdier tripod.
The sweet spot for this mount are the smaller refractors, up to 100mm IMHO.
My mount is totally manual - I have two 300mm flexible handles to drive the mount manually. These make a huge difference to one's comfort and to reducing vibration.
I would be considering a heavier mount if you want to be successfully observing regularly above 150x.
Cheers
Steve

[N1 (Mirko)]

Thanks Guys, a lot of experience right there -

Daniel and Lewis, heaviest scope I'd be putting on it will be around the 5kg mark I think. But I don't even own it yet. All I have now is the FC 76. I had been thinking about the GSO version, but now I'm not
Peter Tan has a resonably priced unit there, although not sure if it's second-hand. I will check out Steve's shop too.

Glen and Steve, a 127mm Istar or even 140mm frac did not make it collapse - that's impressive! Also 100mm f/9 seems to be a good indicator of what's possible without going silly. If I get the Porta II, the handle seems like a sensible idea also. Motors will probably have to wait until later, partly because I'd like to see how good manual operation is over several hours at a time. Surely it will be better than the 410 head; I was actually getting some callus on my thumb & index finger by the end of last winter. I will need the flexible knobs I think. Re tripod, I'll see how I go with mine, then decide whether it needs replaced.

Thanks again

[dannat (Daniel)]

if you buy one look for the extra handle sold by Barry G in Japan here also in the US manny miles used to produce a strengthing bracket..apparently very good, check CN for it

[N1 (Mirko)]

Thanks Daniel; Barry also has a few other things I need..