Ramsey Electronics HR20 manual

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‰25. Install the 9-volt battery snap connector, making sure that the red (+) and black (-) leads are correctly installed.

‰26. Install C7, .01µF disc capacitor (marked 103 or .01 or 10nF).

‰27. Install C8, 4.7-10µF electrolytic capacitor. Observe polarity.

‰28. Install U2, the LM386 audio amplifier IC chip. Just like the SA602, you must correctly position the notched or banded end.

‰29. Install R6, 10K ohm resistor (brown-black-orange).

‰30. Install C12, 100-220µF electrolytic capacitor; observe polarity. This capacitor couples the output of the LM-386 to the speaker jack.

‰31. Install C9, 4.7-10µF electrolytic capacitor; observe polarity.

‰32. Install speaker jack J2. This jack is a 2.5mm type and mates with any 2.5mm plug as found on virtually all mini earphones.

‰33. Install the 9-volt battery clamp. Use a scrap component lead to loop through the two holes in the clamp and through the PC board. Solder the leads firmly to the board and to the battery clamp. Do not use too much solder on the clamp as this will cause the battery to sit too high and not seat securely.

Congratulations! You have completed the assembly of your HR20 receiver kit. Now is a good time to sit back and admire your work and make a final check of all solder joints and component placement. It is always better to find errors now before you test the HR20.

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Contents ALL Mode Receiver KIT Partial List of Available Kits Ramsey Transmitter Kits HR20 Amateur Receiver KIT Ramsey HR-SERIES Amateur Receivers IntroductionAbout Direct Conversion Receivers Circuit Description Parts Supplied with the HR20 KIT CapacitorsLEARN-AS-YOU-BUILD Receiver Assembly Strategy HR20 HR20 Parts Layout Diagram Receiver Assembly HR20 HR20 Required for Initial Testing and Alignment Initial Testing of Your HR20Alignment Hint for ALL Direct Conversion Receivers AlignmentTuning SSB Signals Using Your ReceiverCW Operation On the AIR TRANS-RECEIVINGSpeaker Operation Adding AN LED Power on Indicator More Audio Power Another WAYTroubleshooting Tips General Notes for Experienced QRP Builders Alternate Power SourcesBandspread and Tuning Range Other Methods of Dial Calibration Frequency StabilityDirect Frequency Readout LM386 Audio Output HR20 Construction Notes Ramsey Kit Warranty Factory Repair of Assembled Kits HR20 Amateur Receiver KIT Total Solder Points Estimated Assembly TimeRequired Tools Additional Suggested Items