Vern VanZ <n7gtb@...>
Thanks for the tip on plotting config.
When I first began looking at this batch of crystals, I was using the CTF described here in the PHSNA group; built with the board Jim made up. At that time I was using commercial coaxial cables between the MSNA and the CTF. The response curves were the same. Not knowing if the problem was with some potential mistake I may have made populating the board, decided to build the 'bare bones' version you see in the photos...But as I mentioned, the response curves are the same no matter which CTF is used.
I did try a 10Mhz crystal, from a batch I had purchased about a decade ago, and the response from those units looked pretty much normal. That's what led me to suspect these newer crystals (?)
I do have a couple of surplus adjustable attenuators, made by HP; one is 0 to 12 db, the other 0 to 120. I'll throw the 0 to 12 inline between the MSNA and the CTF, and see what comes of it. I'll also post my findings here for any future interest...
Thanks and 73,
N7GTB - Vern