Ramsey Electronics HR40 manual Troubleshooting Tips

Models: HR40

1 28
Download 28 pages 6.6 Kb
Page 19
Image 19

TROUBLESHOOTING TIPS:

PROBLEM: ALL signals are chirpy and unstable.

SOLUTION: Sorry to have to say it , but this condition is only caused by a weak battery! Use a fresh alkaline cell. Any strong signal forces the audio circuit to rob voltage from the oscillator, which causes the instability.

PROBLEM: Occasionally good but erratic operation.

SOLUTION: Check very carefully for a poor solder connection.

PROBLEM: Signals have an unpleasant hissing pitch.

SOLUTION: Try a different set of headphones, different speaker or external audio amplifier. Some cheap headphones designed for casual music listening have an undesirable filtering effect on CW signals.

PROBLEM: Oscillator inoperative or wrong frequency.

SOLUTION: In addition to checking solder joints, be sure that L1 is oriented correctly and that C1, C2, C3 and C4 are installed in correct positions.

PROBLEM: Loud AC hum or buzz.

SOLUTION: If you are using the receiver with a battery or simply for listening (i.e.: not connected to a transmitter or a AC power adapter), these are likely causes of the AC hum:

No ground connection.

Receiver located too close to an AC device such as an older electric clock, AC-powered radio, etc.

Antenna very close to a power cord or house wiring. If your receiver is being used with a transmitter, the transmitter power supply may be the source of the unwanted AC hum. If you are using a 9-volt AC power adapter, the adapter design may not be of sufficient quality for this application. Try a bypass capacitor, or a different adapter or a well-designed and filtered DC power supply.

A careful check of all construction WILL solve your problem. Over 95% of the kits returned for repair have nothing more than a simple assembly or construction error!

HR40 19

Page 19
Image 19
Ramsey Electronics HR40 manual Troubleshooting Tips