Amen from the crow Burt... thanks. People should also avoid the "cardboard" and fiber type insulators as they can and do tend to be Hygroscopic.
Hygroscopy is the ability of a substance to attract water molecules from the surrounding environment through either absorptionor adsorption. cheers, s. > Burt Lang <[EMAIL PROTECTED]> wrote: > > Delrin (polyacetal) is a bad choice for RF applications. Its > dissipation factor is too high. It is a great "engineering plastic" > meaning it is strong physically but it is too lossy. Teflon (tm) is the > best, also rexolite for RF. Also most any ceramics. Corning has a line > of "machinable" ceramic if you can find it that works great for RF. > > A good test for RF suitable plastics is to put them in a microwave oven > and run it for 10-30 seconds. If the plastic gets hot or even warm, it > is unsuitable or a poor choice for RF. > > Burt VE2BMQ > > skipp025 wrote: > > Re: question about motorola t1500 series cans > > > > The melting was probably done by high circulating current within > > the duplexer cavity. Typical for this type operation. Replace the > > plastic parts with a better (non-plastic) insulator with the proper > > D-factor and you'd be able to rock and roll again using the same > > bottle. Delrin and certain grades of teflon are popular internal > > insulators. > > > > Relative to the same size and types of T-1500 bottles, there > > shouldnot be a lot of other things to go wrong inside the cavity. > > > > cheers, > > skipp > > > > ps: don't forget to replace any plastic SO-239 coax connectors with > > better quality parts. > > > > > >> "Phil" <mts2000uhf@> wrote: > >> > >> I have a set of t1500 series cans that i need to know if they are 250 > >> watt or 60 watt. How can i tell? Was wondering because i ended up with > >> melted notch coupling insulators. I was running 75 watts to the > >> duplexers. > >> > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > >
