Seco Geodesy tribrachs and prism holder with optical plummets
The tribrachs I use are Trimble and are made in Hungary. Beware cheap knockoffs.
I have been using Seco tribrachs with optical plumb with great success for 35±yrs.
Use the Seco 2002-00 bubble adjuster regular to keep them in check
Currently, I have 5 Seco tribrach for sale complete with donut and optical plummet
Have 6 Sokkia/Leitz in my truck that I use daily.
The other two in this picture are for spare parts
message me or send email to h a r r i s s u r v a t y a h o o (with no spaces .com)
Have experimented with cheap/expensive options of tribachs with OP/ tribach with adapter.
1. You cant use the adaptor with OP on a tribach with OP.
2. Do not cheap out on using cheap tribachs or adaptors. The dollars you save initially adds up in the time spent adjusting it weekly or when it has taken a knock. My expensive options hold their adjustments really well and when it was accidentally dropped, the adjustment ran a little. For the cheaper option, I found that that the centering always ran no matter how much thread lock I applied and had to check the centering weekly.
3. My preference is to have the adapter with OP as I can easily check the centering and also the accuracy of the bubble easily.
4. Yes, my traverse results from using a adapter with OP is much better compared to tribach OP. The more sensitive bubble on it plays a part in it.
The Seco Geodesy series seem to be a step up from the standard $140 seco tribrach, at least in price. That being said, I found Leica GDF321's without OP's for $260 each and I'm thing of going that route instead. Any thoughts on those tribrachs?
I found Leica GDF321's for $260 each so I went that route on the tribrachs. They were $20 cheaper each than the Seco's.