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mark steinmann
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Post by mark steinmann » Tue Jan 30, 2007 6:19 pm

What is a VCO and how do i lock it back?

Thanks, Mark

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Post by ohgary » Wed Jan 31, 2007 8:01 am

You might want to take your kenwood 730 question over to the kenwood commerical forum. From wikipedia A voltage-controlled oscillator (VCO or ) is used when the frequency of operation needs to be adjusted by a relatively small amount, or when exact frequency or phase of the oscillator is critical, or, by applying a varying voltage to the control input of the oscillator, to disperse radio-frequency interference over a range of frequencies to make it less objectionable. Typically the frequency of a voltage-controlled crystal oscillator can only be varied by a few tens of parts per million (ppm), because the high Q factor of the crystals allows only a small "pulling" range of frequencies to be produced.

How will depend on the radio, will often require a service manual and some metering devices.

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Post by k2hz » Wed Jan 31, 2007 11:04 am

If the VCO is out of lock, it could indicate that either an out of range frequency has been programmed or the VCO is defective.

In some cases a VCO can be returned to slightly shift the frequency range.

If you have to ask what a VCO is, I doubt you have the knowledge and test equipment to attempt to adjust it. VCO adjustment procedure would be described in the alignment procedures in the service manual for the particular model radio.

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