Right at the start of my conversion information I mention you should begin with the repeater working well at the original frequency. I probably should include the advice to do the frequency conversion first before you do my or anyone's modification. Just so you know you are not fighting multiple gremlins.
Per the post by Eric... it's probably a good idea that you supply the Model number(s). The printed model numbers direct off the Receiver and Transmitter Modules as well as the RF Amplifier. The cabinet model number is pretty much a must have to know the entire package. Another thought... when you moved the rf units down to the ham band... did you realign them from their last positions or did you start the realignment after placing the coils at the manual chart position (yeah it does make a difference)? If you did my mod with the DB-9 type jack option... you could easily make a matching plug to restore the unit to near stock operation while you figure out what's going on. Sometimes you find receivers and transmitter strips without the duplex filter networks on/near the tx/rx module end connectors. But I've run both the duplex and base station (only) tx/rx modules as repeaters with nary a squawk. Also... with your PA output reduced... cable direct from the PA output jack (not the cabinet jack) direct to a termination (load) while you're testing. Do you have the problem when going direct from the pa output to a termination (not using the cabinet internal duplex cables)? During conversion mods... people often tie wrap cables in a bunch to make a clean install. Combined tx/rx coax cables are often a potential source of trouble. What kind of coax did you use to make the in cabinet rf cables? skipp > "tomnevue" <[EMAIL PROTECTED]> wrote: > > I have 2 VHF MSR2000 Repeaters that I'm building up at the same > time. Both units have the same problem and I'm hoping someone with > MSR2000 experience can give me a suggestion on where to look next. > > I'm having a terrible time with receiver desensing, transmitter > hanging on and audio oscillations (intermittent/random growling). > I've been thru separate antennas, duplexer with better than 90dB > notch, separate antenna with duplexer + extra cavity. If I run the > duplexer antenna port into a dummy load, the problem is less but > still there. If I run the transmitter port directly into a dummy load > or if I turn the PA power down to about 4 watts (with > duplexer/antenna connected)the problem is gone. I've replaced the > repeater/duplexer jumpers with good double shielded coax and ground > strapped the repeater/duplexer cabinet together. I've made sure all > of the original repeater panels are in place. The problems exist with > the controller in place and also with a test connector replacing it. > > One of these was a full working repeater in public service use and > the other was a convertable base station. Both have the 110watt PA > that I am running at 50 watts. The controllers are NHRC-2 connected > to the Squelch Gate card using the procedure described by Skipp May. > The 12 inch interconnecting cables use shielded audio in/out cables > and COS/PTT wires are not shielded. The controllers are enclosed in > aluminum boxes. > > HELP !!! > Tom W2MN >
