There is an older T1500-series manual on the web site that goes along with this Yahoo! Group.
There are two rather different coupling loop assemblies/setups in those cans: those that arranged for the notch ABOVE the passband, and those that are arranged for the notch BELOW the passband. I doubt you can arbitrarily reverse them. The various cable sets are only documented by the colored dots on the connectors. I didn't see any actual cable lengths. I think they use the same unit on the Quantar and there might be a newer document in that manual, but I doubt anything has changed in those cans in 30 years. Bob M. ====== --- On Wed, 12/3/08, Joe Burkleo <[EMAIL PROTECTED]> wrote: > From: Joe Burkleo <[EMAIL PROTECTED]> > Subject: [Repeater-Builder] Re: Motorola Duplexer Info Needed > To: [email protected] > Date: Wednesday, December 3, 2008, 4:20 PM > Bill, > That is interesting that you are having the problem with > the duplexer > not tuning down to 440.8. > > This duplexer that I have will tune down to at least 440.0 > with no > problem on the duplexer running out of pass tuning range. > The problem > that I am having is with the notch sliding adjustment on > the top of > the cans running out of adjustment range on the notch > tuning. The > screwdriver pass tuning adjustments on the front of the > unit have > plenty of range. I never did run them all the way in just > to see how > far they would go, but they will go well below 440.8. I > will try your > suggestion of tuning it up on the higher end of the band > tonight if I > get home early enough. > > I have one of these style duplexers on our 444.525/449.525 > 225 watt > Micor repeater running at 150 watts with a Angle linear > preamp on the > receiver with no problems, so I know they can be made to > work at the > higher end of the band. > > I don't think a T1500 deries duplexer will perform as > well at that > power level. > > I was hoping someone had a manual that covered the > duplexer. I can not > find any reference to the specifications or parts list in > the MSR or > MSF manuals that I have. > > Thanks, > Joe > > --- In [email protected], "Bill > Hudson" <[EMAIL PROTECTED]> wrote: > > > > > > > > Joe > > > > > > > > You just happen to have one of the series of duplexers > that does not > make it > > all the way down into the bottom of the ham band at > 440.xxx Mhz. > > > > If it truly is the Motorola duplexer out of the > MSR2000 series > repeaters, > > they - in fact - do not tune down to the bottom of the > band. The > original > > T-1500 series duplexers make it fine, but the > mechanics of the tuning in > > these specific cavities "bottom out" before > making it to the lowest > part of > > the 440 - 450 MHz. band. > > > > > > > > What you are experiencing is normal. Trying tuning it > up in the 444.9 / > > 449.9 range, and you will see it works fine. > > > > > > > > Maybe you can trade it with one that you know will be > going on a higher > > frequency. > > > > > > > > Interesting timing on your post. I just became aware > of this myself a > > couple of months ago. > > > > > > > > Bill - W6CBS > > > > > > > > _____ > > > > From: [email protected] > > [mailto:[EMAIL PROTECTED] On Behalf Of > Joe Burkleo > > Sent: Tuesday, December 02, 2008 11:24 PM > > To: [email protected] > > Subject: [Repeater-Builder] Motorola Duplexer Info > Needed > > > > > > > > Hello, > > I have a Motorola 4 can duplexer out of a UHF MSR2000 > series radio > > that is the pass/notch style. I am pretty sure > Motorola also used > > this same duplexer on the MSF5000 series of radios. I > can not find any > > info on this unit and I am having a problem with the > notch on the low > > pass side. I can not seem to adjust the notch past 4.5 > MHz spacing. It > > will adjust down to 3 MHz spacing just fine. The notch > on the high > > pass side adjusts just fine and will actually go a > little beyond the 5 > > MHz spacing. > > > > The pass adjusts properly on both sections of the > duplexer. > > > > It was originally on 464/469 and I retuned it to > 440.8/445.8. The > > notch problem was there on the original frequency as > well. > > > > I am using a IFR A-7550 analyzer/tracking generator > for alignment. the > > duplexer has very good insertion loss and the notches > are -100 db, so > > it is meeting specs very well, other than the one > notch being off. > > > > Has anyone ran across this before or have any ideas. I > though I would > > ask the group, before I started drilling out pop > rivets to disassemble > > the cans from the mounting bracket. > > > > Thanks, > > Joe
