I have two UHF mobile duplexers. One from, supposedly, a Motorola, and had been tuned down to the 440 band, the other I stripped from a garbage Motorola unit, have not tried retuning it. Either would be good for up to 50 watts, but maybe not much more. And they can be had fairly cheap when you find them. They work well on a 5 MHz split. The VHF mobile duplexers are also usually designed for a 5 MHz split, and as such are of no use on 2 meters. But still might be useful on the 440 band. But, as you say, why buy them when the ones made for UHF can be obtained really cheap? The duplexer I have that seems like it will work on the 440 band is not a mobile unit, but does use cans that are actually smaller than the Micor UHF duplexer I have, as well as the Decibel unit in my repeater. I bought it as supposedly being a 6 can unit, and the seller did give me a full refund and told me to keep it. And, as I said in another post, it does seem to tune to the 440 band readily enough. Maybe use it on a project later on here, being as I plan an E case mobile as a backup repeater. though I might just put a mobile duplexer in that, depending on the PA power. Regardless, some of those duplexers might be able to be used on higher bands. YMMV
Wayne WA2YNE --- In Repeater-Builder@yahoogroups.com, [EMAIL PROTECTED] wrote: > > Plain 1/4 wave pass cavities usually work just fine at their 3/4 > wavelength, i.e. 2 meter pass cans will work @ 440 MHz. I've heard from > several sources that this works with BpBr duplexers as well, though I've > never tried myself - I saw at least one 72 MHz duplexer being sold at > Dayton as a 220 3/4 wavelength duplexer. > > Mobile duplexers are a different story, as the VHF units are electrically > short (& maybe the UHF ones too), so there would be quite a bit of > modification needed to move one. Given how cheap & plentiful both are on > the used market, it's probably easier to just buy the mobile duplexer you need. > > Bob NO6B > >
