THANKS FOR THE REPLY. PLEASE SEE MY NOTES (CAPITALIZED). --- In Repeater-Builder@yahoogroups.com, "skipp025" <[EMAIL PROTECTED]> wrote: > > > "tomnevue" <w2mn@> wrote: > > Thanks for all the input. I have some information now > > and I hope I'll have the rest tomorrow. > > Great... "you've got questions..? We've got answers..." Where have > I heard that before? > > [major text edit (for sanity)] > > Repeater was at 155Mhz with a 700Khz split. I confirmed that the > > repeater was fully operational before doing any Ham conversion. > > excellente' > > > I did this by operating into a dummy load and using 2 HT's that > > were part of this system. > > Well... not the test I had in mind but what the heck. Onward... > > > The only thing done to the repeater for Ham conversion was > > retuning, moving the configuration jumpers needed and > > modifying the Squelch Gate card per Skipps article. All internal > > cabling is exactly as supplied by Motorola. > > He's a trouble maker... I know him well. > > > The Sinclair Q202 (4 can) duplexer was aligned in a laboratory by > > someone who has experience doing this; notch slightly better than > > 90dB. This exciter has the added backplane filter plug assembly. > > Per my previous post... I'd park the duplexer and service only the > repeater until you find the problems. You also mention going from > an original 700KHz repeater offset to an Amateur (2 meter band) 600KHz > offset. Are you using the same duplexer?
SAME DUPLEXER. I'LL PARK IT AND KEEP WORKING ON THE REPEATER UNIT. > > > The base unit was at approximately 155Mhz also. I moved jumpers as > > needed to look like the repeater. I got another SG card and made the > > same modification. > > You should keep one Squelch Gate Module Stock until you get one > repeater station working as normal. Just keeps your sanity to have a > known original/standard for benchmark testing. YUP. THAT'S WHY IT'S UNTOUCHED. > > > The Rec / Trans cables are the same cables supplied by Motorola > > with TR switch removed and bulkhead connectors added. So, the Base > > looks just like the original repeater. > > No it is not..! There are a number of different tr relay cables used > and they don't full duplex well without some bit of caution. Is your > rx cable a small white only cable direct to the output jack and is > that jack cable connection sealed 100% with a rear mounted SO-239 > jack "coax hood"? I HAVE NOT TOUCHED THE CABLES ON THE ORIGINAL MOTO REPEATER UNIT. THE RX CABLE IS SMALL WHITE AND THE TX CABLE IS BROWN. BOTH GOING TO SO239 WITH RF SEALED BACK. THE CABLES ON THE MODIFIED BASE HAVE THE TR SWITCH REMOVED AND MOUNTED TO S0239 WITH RF SEALED BACK. THESE ARE SMALL WHITE, WITH THE TX CABLE BEING SLIGHTLY LARGER. > > The PA output cable should be Brown RG-393/400U or similar type > teflon coaxial cable. Unless you have the luxury of some semi small > rigid coax (hard line) you can use. If you're using the white relay > coax in the repeater tx line... part of your problem is leakage to > & from the small white coax. OK THIS COULD BE A FACTOR IN THE MODIFIED BASE BUT THE REPEATER AND MODIFIED BASE EXHIBIT THE SAME OPERATIONAL PROBLEM. > > > The jumper cables from the repeater cabinet to the Duplexer is > > Milspec RG400 and no adapters are used. > > Ahhh....! TAKE THE LMR-400 COAX AND THROW IT AWAY! Replace it > with some RG-214 (mil spec type). NO NO NO NOT LMR-400. RG-400U MIL SPEC,DOUBLE SILVER BRAID, TEFLON DIELECTRIC, BROWN JACKET. 4 FT FOR EACH JUMPER. > > One item to note... If you were testing all this with just the > repeater first (no duplexer per my post). You would not have to > worry about the LMR-400 hosing up the works until you later > confirmed the repeater is working normally. > > Once again... TAKE THE LMR-400 COAX AND THROW IT IN THE TRASH! > > > I pre-adjusted the coils the amount estimated by the graphs > > excellente' > > > I built a test meter and followed the step by step instructions > > to tune the RF circuits. > > I really don't what to mess up a good thing... but the metering > point values displayed by the original 50uA meter movement (test > box) will actually be slightly different from the same test point > when using a Multi Meter. Just something to know... BUILT THE METER BOX AS DESCRIBED IN THE MANUAL; 50uA METER MOVEMENT, MULTIPOSITION SWITCH, PLUG CONSTRUCTED FROM SOCKET (WITH BRASS PINS ADDED) SALVAGED FROM OLD MOTO MOBILE UNIT. > > > I netted the crystal. > > Smell like fish? just kidding... TOO SMALL TO GRAB WITH MY BARE HANDS; HAD TO NET. (hihi). > > > I did not make any adjustment to the modulation at this point. > > If the repeater has the original ctcss "pl" module/card in place > you need only confirm the transmit ctcss level is about 700KHz and > you can consider the tx channel element IDC value is pretty close > to where it should be for normal voice operation. SAME PL UNIT. > > > The starting points for tuning both the receiver and > > transmitter were very close to the final settings. > > Should be... although some of the metering point dips and peaks > are really, really small in value. You have to be watching the test > point meter locations with a quality meter and a bright light to > make sure you reach the right coil positions/locations. I RECALL ONLY 1 ADJUSTMENT THAT DIDN'T HAVE A WELL DEFINED PEAK / DIP. I THINK IT WAS ON THE RECEIVER. I WOULD HAVE TO CHECK MY NOTES TO SEE IF I MADE A COMMENT. > > > > When the transmitter power is turned up above 4 watts into either > > a separate antenna or the duplexer or combinations of duplexer > > separate antennas the receiver is badly desensed, > > You should have the pa output parked into a termination (load) for > most all this early testing. YUP. I HAVE A SPARE 80 WATT MIRAGE (?) AMPLIFIER THAT I WAS THINKING OF SUBSTITUTING (FOR TEST PURPOSES) TO ELIMINATE THE PA AS A PROBLEM. NOTE THAT I DON'T SEE A PROBLEM UNLESS I'M RUNNING POWER. IF I RUN WITHOUT THE PA, I EXPECT EVERYTHING WILL BE OK (AT ABOUT 2 WATTS). > > > the repeater randomly hangs and sometimes makes a loud growl > > sound when dropped. > > "doesn't know the words" WHEN ht STOPS SENDING, REPEATER SHOULD DROP BUT IT RANDOMLY HANGS (ON), THEN DROPS, AND OCCASIONALLY GOES BACK INTO TRANSMIT WITHOUT THE ht. SOMETIMES THIS DROP AND RESTART IS ACCOMPANIED BY A LOUD GROWL SOUND IN THE AUDIO. I'M FIGURING THIS IS SOME KIND OF RF LEAKAGE BACK INTO THE RECEIVER OR FOR SURE THE AUDIO PATH. THIS CONDITION EXISTS WITH / WITHOUT A CONTROLLER AND ALSO WITH THE UNMODIFIED SG CARD. > > > I tested the 2 units with a 3rd unmodified SG card and had > > the same problem. > > Helps isolate the mod as being a source of the problem(s). > > > Have I missed anything?? > > Yeah... a bit. Trash the LMR-400 Cable. Per my first post... take > the repeater pa output direct from the pa to your termination/load > for testing. also get rid of (replace) the hacked and soldered > tr/relay coax cables. Make 100% sure your cabinet side mounted > SO-239 jacks have the proper rear mounted hoods (shields). ... that > is if you end up even using the original internal cable paths. > Sometimes it's worth doing something different. ... and make sure > the cabinet internal (and external for that matter) coax cable paths > have as much separation as possible'. > > Buy some RG-214 mil spec version coax cable for the duplexer cables > and a bottle of Petite Sirah to help with the operator lubrication. NOW STARTING TO USE LARGER QUANTITIES OF "SHINER BOCK" (A TEXAS THING) TO LUBRICATE THE OPERATOR. > > ... and club the person who gave/sold you the LMR-400. THE ONLY SINGLE ITEMS THAT I HAVE CONSISTENTLY USED ON BOTH REPEATER UNITS, WITH ALL THIS TESTING, IS THE FREQUENCY ELEMENTS. WHEN I SET THESE UP, I SIMPLY REPLACED THE CRYSTALS AND JUST SLIGHTLY ADJUSTED THE SINGLE FREQUENCY CONTROL. I HAD NO PROBLEM GETTING THE ELEMENT TO OSCILLATE OR MOVE ON TO THE EXACT FREQUENCY. CRYSTALS FOR THE OTHER FREQUENCY ARE EXPECTED TO ARRIVE TODAY. I SHOULD HAVE THEM INSTALLED IN THEIR WAITING ELEMENTS AND BE ABLE TO TRY THEM TOMORROW. TOM W2MN > > cheers, > s. >
