I have tuned on 2 of the U51LLT radios and many of the L receivers that were in the later low-band motracs, all going to 52-53 MHz.
I never had a problem getting a L receiver to tune to 52.525 MHz or the 53 MHz repeater output band EXCEPT for the multiplier stage needs to have about 3 capacitors swapped out for higher range. The front end coils always tuned up fine for me. On the 2 LLT transmitters I tuned, one exicter tuned up fine and the other exciter tuned up with the output slug nearly out of the coil form. The transmitter with the exciter output slug coming out of the coil form peaked at about 47 watts. I always wanted to try replacing the capacitor with a lower value to see if the full 50 watts would appear, but never did actually try it. ------ Original Message ------ Received: Tue, 24 Jul 2007 11:05:38 PM CDT From: "tallinson2" <[EMAIL PROTECTED]> To: [email protected] Subject: [Repeater-Builder] Re: old Motorola > "or to push to 52MHz for the amateur 6 meter band)." > > Mike, > Did I understand this correctly? The 42 to 50 split can be pushed to > the 52Mc repeaters without modifying the front end? I have a U51LLT > Motran that I would like to put on the 6m ham band, but digging into > those front end coils has scared me off a bit (there's too darn many > of them). Would be great if it could be pushed to 52Mc without > mods. Also, someone on here mentioned the channel elements. My > channel elements for that radio were lost when I moved to this house > and I haven't been able to find any. If there are any spares > floating around for the "L" transmitter and "L" receiver, either one > or two channel, I'd sure like to buy them. The ones that were in > there were TLN1022A and TLN1020A, but I'm told that the TLN1080 > series will work also. If anyone has anything, please email with what > you have and price. Thanks, > Tom KB5DPE > > > --- In [email protected], Mike Morris <[EMAIL PROTECTED]> > wrote: > > > > At 09:28 AM 07/22/07, "Eric Lemmon" <[EMAIL PROTECTED]> wrote: > > >Rich, > > > > > >A C71LHB-3400C is a Compa-Station Base Radio for 25-50 MHz, 100 > watts, > > >Private-Line, and DC remote control. The manual that covers it is > > >6881005E40, which is no longer in print. I am assuming that the > model > > >number tag actually represents the equipment inside. > > > > And Rich - that radio is NOT going to cover 30 to 50mhz. It's > built > > for a subset > > of those frequencies, called a "range" or a "split" in Moto > terminology. > > > > The "4" in 3400 indicates that you have a dual receiver unit, or at > > least the radio > > that was in the cabinet originally did. > > > > The low band Motracs came in three ranges: > > (1) 30-36mhz (which can be pushed to 28mhz for the 10 meter band) > > (2) 36-42MHz (pretty useless except as parts, or maybe for a > Volunteer > > Fire Department that has channels there) > > (3) 42-50MHz (useful to Red Cross, which has a nationwide channel at > > 47.42Mhz, or to push to 52MHz for the amateur 6 meter band). > > > > It's not practical to try and range change a low band Motrac as you > > would have to modify (or rewind) some coils. > > > > Did it come with the Channel Elements? They are little blue or > > gold aluminum cans that plug into a cluster of 4 pins in the > receiver > > or transmitter. The receiver had locations for 2, the transmitter > for 4, > > and an option board added slots 3 and 4 to the receiver. > > > > Setting that unit up on channel, assuming you have the channel > > elements, is about $40-50 if you re-crystal the elements yourself, > > or more if you have the crystal house do it. And they you get to > > tune it up. > > > > Mike WA6ILQ > > > > >
