The discussion about the potential effects of BNC to SMA adaptors got me to wondering if I could see any difference with the IBZ DS800C 4GHz scope that I have.
I hadn't used it much before, and don't normally deal with anything this fast, so it was a bit of a learning curve... With the pulser I was finally able to give it a proper workout.
These are connectors that I used and some prices:
An old surplus Huber+Suhner. No idea of the model, but it looks like RS 716-4779, which is £61.69+VAT.
Emerson VA506. It was from ebay, but is £5.43+VAT from CPC
Cinch 29-3855. It was £2.95+VAT from RS
Also from ebay: “Handy Utility Adapter BNC Female Jack To SMA Male Plug RF Connector Straight EW” #401116160491. £0.99 including post from China.
There are probably a few more (or at least larger) variables involved when using this scope than something like a CSA803, so the rise times are a bit of an estimate. I also only tested one sample of each.
Anyway, the numbers that I came up with for now are:
52ps H+S
53-54ps Cinch 29-3855
54-55ps Emerson VA506
58-60ps ebay 99p
The sheet I got with this pulser gave the measured rise time as 31.8ps
Has anyone tried this with something more stable? This is rather pushing the limits of a scope that is $300 new!
Deliberately moving/loosening the connectors did suggest that there was not really much instability caused by this adaptor - although I would still like to get hold of an SMA version, and something a bit better to test it on.