| Author |
Message |
    
Teham
New member
Username: Teham
Post Number: 5
Registered: 1-2004
| | Posted on Thursday, July 01, 2004 - 11:20 pm: | 
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I have a TRC 490 that is off freq on lsb and usb. Which crystals are bad? Have no way to test. THNX Tony |
Tech548
Moderator
Username: Tech548
Post Number: 122
Registered: 5-2004
| | Posted on Wednesday, July 07, 2004 - 2:48 am: |
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Teham
Neither of them are bad. They're just out of adjustment. Crystals very rarely go off frequency unless someone has tampered with their adjustable vari-caps. Each crystal in that radio is adjustable whether it be though a capactor or a tuning can.
Just one cap or can being out of adjustment will show up on a frequency counter as being "Off Frequency".
Try this.
Assuming you have modified your clarifier to track on transmit along with the receive, put your clarifier at center slot. Get someone to go to "Center Slot" USB with you and clarifier into them by adjusting CT-3. Then go to LSB and clarify them by adjusting L-19.
Since you didn't say if your clarifier has been modified or not, this is as far as I can go with helping you. But if you do indeed have an opened clarifier, this method will get you closer to being ON frequency in the USB and LSB modes "but" will only be as accurate as your helper's radio you just used as a reference.
Jeff. |
Teham
Junior Member
Username: Teham
Post Number: 14
Registered: 1-2004
| | Posted on Thursday, July 08, 2004 - 12:05 pm: |
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Clarifier isn't opened up. Can use my Kenwood as a reference so will be accurate. Still turn same things and adj. what you told me? Can put dummy load on RS and adjust while transmitting. Tony |
Tech548
Moderator
Username: Tech548
Post Number: 126
Registered: 5-2004
| | Posted on Friday, July 09, 2004 - 3:54 pm: |
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Teham
Excellent frequency source but the accuracy of your 490 will only be as accurate as the Kenwood's accuracy.
If you already haven't done so, check your Kenwood's frequency accuracy. The frequency “standard” of the WWV time can be found on 2.5, 5.0, 10.0, 15.0, and 20.0MHz. Once you know that your Kenwood is dead on frequency, is will make an excellent (On Frequency) source when calibrating other radios.
Anyways, if you have the manual for your TS-930, it will show you how to get your frequency display to show (dead-on) frequency. Just be sure that the radio has been at idle for at least an hour or so.
Jeff,
Tech-548 |
Teham
Junior Member
Username: Teham
Post Number: 22
Registered: 1-2004
| | Posted on Saturday, July 10, 2004 - 1:25 pm: |
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Got it. THNX for the help. Tony |
