SuperStar Cutting Out

[Tnengineer]

Hello. My SuperStar 360FM has a strange problem. Both receive and trans will go silent for a period of say 2 to 15 seconds then return. Meter still is lite during this blank time. Otherwise performance is good. Any ideas?

 

[sp5it]

VCO malfunction to check.

 

[nomadradio]

I would tune in the stray RF leaking out around the 10.24 MHz crystal, and listen in with a ham or shortwave receiver that covers that frequency. You can try molesting the 10.24 crystal while listening to the carrier coming out of it. Tuning in the 10.24 MHz carrier using the receiver's sideband mode will get you a steady tone that should not jiggle about in pitch when you tap on it.

And if you can stand to listen to it this way until it cuts out, this will tell you if that crystal is what's cutting out or not.

More than one part of the PLL circuit can cut out and kill the receive/transmit, but that's where I would look first.

73

 

[Tnengineer]

I would tune in the stray RF leaking out around the 10.24 MHz crystal, and listen in with a ham or shortwave receiver that covers that frequency. You can try molesting the 10.24 crystal while listening to the carrier coming out of it. Tuning in the 10.24 MHz carrier using the receiver's sideband mode will get you a steady tone that should not jiggle about in pitch when you tap on it.

And if you can stand to listen to it this way until it cuts out, this will tell you if that crystal is what's cutting out or not.

More than one part of the PLL circuit can cut out and kill the receive/transmit, but that's where I would look first.

73

Yes the tech replaced that crystal to repair. Many thanks!