[R-390] R390A Dead Filters

[Glenn Scott]

Hi,


I need some dead R390A filters for test and development of my Arduino driven coil winder and test my hardware setup.. Still working out some small issues with the system but its coming together slowly.
Units with open coils or high insertion loss but cosmetically OK are best. These will be for test and R&D work for now. My preliminary work has been encouraging with slightly less insertion loss than the cruddy filters I started with and the various passbands looks decent on my HP 8566B spectrum analyzer with tracking gen.


By chance, I recently met a 91 year old Collins EE who did a lot of the development work on these filters back in the day. I am saving his notes and may place them here soon if there is any interest. The notes are basic and explain some of the processes for evacuating the filters and filling them with N2. He also explained how he had Co-op EE students who fine tuned the resonator plates with razor disc for optimal performance, during the evening hours. (beats delivering pizza's...Hi)


I may offer a repair service for filters later if I can get a few bugs solved in my setup and if can get more serious about working with such a fine PITA wire; Jeez.


Give me a reasonable price for your dead units and I can send a Biz check or PayPal payment. Remember they are DEAD units and not ePay gouge worthy; just saying.


You can contact me off list: glenn at dsmlabs.com


Thanks,


Glenn Scott WA4AOS
341  Colonial Acres Road
Laurens, SC 29360
864 684 2956