RCI 2970 Pinched Up on USB

[Wire Weasel]

Have older 2970 non DX. USB and LSB are right on frequency. LSB sounds "normal", full bodied audio. USB sounds pinched up and tinny like it is experiencing a very narrow bandwidth or something.

Is there a bandwidth adjustment or something else that can adjust the tone sound on USB?

 

[Robb]

Prolly needs an alignment . . .

 

[jazzsinger]

Have older 2970 non DX. USB and LSB are right on frequency. LSB sounds "normal", full bodied audio. USB sounds pinched up and tinny like it is experiencing a very narrow bandwidth or something.

Is there a bandwidth adjustment or something else that can adjust the tone sound on USB?

check the usb offsets are spot on,its possible to be on frequency but not have the offset on the right frequency if the opposing offset is out by the same amount, this would narrow or widen audio depending if you set the offset more than the standard 2.5 khz or less than it.. something that is very possible if the radio was aligned by ear on another radio rather than having the internal oscillators calibrated against a good counter.

 

[Wire Weasel]

Could you point me to where these offsets are inside the radio / part I.D. like L 25 or whatever it may be?

Thanks!

 

[Robb]

You are going to need a real frequency counter and a voltmeter. A scope would be nice for a couple of the adjustments; but for the purpose of getting it on freq - then those two tools are enough. I'm talking about a real reference freq counter here; not one of those 'toys' used for a radio display.

Ranger RCI-2970 Service Manual

Do all of these steps - except for the o-scope adjustments.
That should set it straight again . . .

Wouldn't hurt to give it the full alignment at this time.