Sean, something like the MVAM109/MVAM125 wold be great, just one of those diodes could replace the entire bank. Sadly, they appear to be (effectively) obsolete/EOL. Since I'm confining myself what is readily available from the catalogs of the major electronics distributors (ie. Digiket, Mouser, Farnell, etc..), I won't be able to use it. However, it is quite handy to know that those really big varactor diodes exist, even if they are hard to get ahold of. As for the 1N400X diodes, I looked and their overall capacitance (~20pF) is not quite enough for my application. On Thu, Oct 20, 2016 at 1:54 PM, Sean Breheny wrote: > There are also older varactor diodes with a much larger capacitance, such > as the MVAM109 or MVAM125. There are a few sellers on eBay who have these= .. > I don't know if they are made anymore but there are still sources. I used > some in a receive-only remote antenna tuner I made. They have about 10x t= he > capacitance of the ones you are using now, and almost as large a cap rati= o. > > On Thu, Oct 20, 2016 at 12:16 PM, Van Horn, David < > david.vanhorn@backcountryaccess.com> wrote: > >> You could use mosfets to switch in capacitors in binary values, then may= be >> use a varactor or two for fine tuning. >> >> They DO still make the old 365pF variable caps, BTW. >> >> >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 Jason White --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .