Russ, If the receive is intermittent, your problem is likely NOT the LO being off-frequency. An LO that was off would rear its head as sounding off frequency or poor sensitivity. I have had some problems with the LO crystals drifting as of late, but I don't think that is your problem from the description you provided. At any rate, the second LO crystal frequency is 44.645 NOT 45.645. The IF frequency is 45.10, so 45.100 - 44.645 = 455KHz.
It sounds to me like you might have a broken/cracked solder joint somewhere inside the radio or that the Rx VCO is going out of lock. Does it seem to be temperature related? If so, that would lead more toward the VCO. You can open the radio and VCO compartment and see what the voltage is on the test point marked "SL." It should be around 7v or so. If not, you can adjust the Rx VCO coil to get it more in-line where it needs to be. Good luck, Scott Scott Zimmerman Amateur Radio Call N3XCC 612 Barnett Rd Boswell, PA 15531 ----- Original Message ----- From: "russcrisp" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Wednesday, October 03, 2007 1:44 PM Subject: [Repeater-Builder] Help with Motorola Radius M120 - Intermittent Recieve >I have a Moto M120 UHF that has intermittent receive. Doesn't work more > than it does.. A friend suggested that I count the Second LO, and make > sure it's at 45.645 Mhz. I have no service documentation on this model, > so rather than poke all around looking for something that may not be > there, I thought I ask the group here for assistance. > > Does anyone have experience with the M120? Is this indeed the correct > setting for the second LO for a UHF radio? 438-470.. Where is the > proper place to attach a counter to measure this? > > Any help would be greatly appreciated. This radio is used in a link. > > Best regards, > Russ Crisp > K4RCC > > > > > > > Yahoo! Groups Links > > > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.488 / Virus Database: 269.14.0/1046 - Release Date: 10/3/2007 > 10:08 AM > >
