Just curious so what to look out for and what to avoid in the world of used and prices and do some have gen 2 tubes, think my longbow gen 2 and it’s ok, looked through pvs14 different league, owner had no idea about tube?
The market is now more complicated than it used to be.
PVS14 (Personal Vision System no. 14) is a military requirement design - and so many different types of manufacturers produce their own versions to this specification. Then there are the lookalikes and those built for different uses (ENVIS for example).
On top of this were required tube specifications - in later days called OMNI contracts. While complying to these standards, lots of different manufacturers produced tubes to these specifications - to sit in these various bodies. Just because something is of a later specification, it doesn't make it better. It is just designed to meet the specific minimum needs of the contract. The specs of the specific tube can be found on the tube itself, normally with an NSN and a manufacture date - by unscrewing the lens.
On top of this there's the generation game. Gen 3 is not necessarily better than Gen 2 - it is a different technology.
Clear so far?
So then you have the introduction of commercial grade PVS14 clones on top of the originals. These can be bought on the open market, are warranted - and in the main obscenely expensive. Few meet the light gathering performance of the military items - but the military versions were rarely designed to be weapons mounted (and if they were, only on 5.56 in the main) - and tend to be inherently more fragile. Gen 2+ and in particular the Photonis brand of tubes have a different construction and so are more often more resilient. Some manufacturers will rate their monoculars against recoil.
What to look out for - gosh.
Well PVS14 is a relatively old unit these days.
Look for a lack of body wear.
Listen for electronic 'whining' when turning on - and any delay in coming on.
Ensure the manual gain works
Check the lenses closely. PVS come with sacrifical lenses and so the lenses should be as free of scratches and dirt as possible
Make sure the dioptre and the focus both have a smooth full range of turn
Turn the unit on against a clean sheet of white paper - you want as few marks as possible (small ones are to be expected - it is an organic product) - beware any burns or dull spots
Check battery compartment and connections - clean and tight.
Check whether the autogating works
There's a starter for ten anyway.....
In terms of against a Longbow - it will be - far less glass etc for light to come through - and very different tubes. With the IR's available these days however, the gap has shrunk (we don't need to use these units passively).
Next time.....Figure of Merit (FoM)......
