Light Bulb Test
From “SGC” @: http://www.sgcworld.com/support/lighttest.html On Site Radio HF/SSB Transmitter & Coupler Test Procedure Light bulb test. If you suspect that there is a problem with your transmitting equipment, here is a simple test that you can perform to find out if your station equipment is operating properly. All that is required is some hook up wire, a PL-259 connector, 2 alligator clips, a lamp socket, 100 watt lamp or a minimum 200 watts for 500 watt system (two may be paralleled if necessary), and adapters as shown in the diagram. In a real emergency, you can simplify this arrangement to suit the materials that you have on hand. 1 - The light bulb test is used to verify basic operation of the transmitter, and antenna coupler. The lamp will present a load to the transmitter, and antenna coupler that is similar to an antenna. This test will provide a visual indication of the power output from the transmitter, and verify operation of the antenna coupler. 2 - The transmitter should be tested first. Note that the lamp may be dim on some frequencies. This is because the lamp is not an ideal load for the transmitter, and the SWR protection circuitry in the transmitter will automatically reduce transmitter power. If the lamp does not light on any frequency, there is high probability that the transmitter is in need of service, and there is no need to proceed to the coupler test. 3 - If the transmitter passes the test, proceed to the 'coupler test procedure'. Make sure that the antenna and ground are first disconnected from the coupler. Note that you should be able to hear the relays clicking in the coupler as the tuning cycle begins. This should stop within a few seconds, and the lamp should light brightly. If you are using the tuned indicator option, it should illuminate when the coupler is tuned. 4 - This test should be repeated on all bands of intended operation. Note that the coupler will probably not tune the lamp from memory. This because the impedance of the lamp changes with temperature, and therefore presents a dynamic load to the coupler. 5 - Note that the lamp will not be as bright on the higher frequencies. This is due to the fact that some radiation from the hook up wiring will occur on the higher bands, that is, some of the power will go 'on the air' and not be available to the lamp. 6 - If the coupler operates as described above, it is almost certain that it will give satisfactory service with a proper antenna. If you are still having trouble, we hope that you will contact us for a free copy of our HF SSB User's Guide and Products Catalog which contains much additional information. If the lamp does not light: 1 - Make sure that the radio is set to the CW mode. Some transceivers may not provide CW output unless a CW key is connected to the appropriate connector. If you are not sure about this, refer to your equipment manual. You may use FM or AM instead if necessary. 2 - Check the voltage at the transceiver DC power terminals. Also, verify that there is at least 12 volts available at the antenna coupler. 3 - You can check the SSB output of your transceiver by speaking into the microphone. The lamp will not be as bright as in CW. This is normal. 4 - Keep in mind that most troubles with these installations will be found in the wiring, coax connectors, and antenna/ground system. 5 - If there is no indication of transmitter output you will need to make arrangements to have the unit serviced. 6 - If transmitter output is good, but the coupler does not tune up the lamp, you should contact SGC for help. If your equipment passed these tests: 1 - Your equipment is capable of producing a strong signal. If you are having trouble, it is probably either in the antenna system, or your operating procedure. 2 - Make sure that your antenna and ground system are installed correctly, contact SGC for a copy of our HF User's Guide for much additional information on this subject. 3 - If you are new to HF radio, we strongly suggest that you set up a schedule with another station for your initial tests. A helpful operator at the other end can provide much useful information about your station performance. 5 - The technical support staff at SGC has many years of experience in all facets of HF radio communications. If you need help with your SGC equipment, please contact us. We stand ready to provide solutions to your communications challenges. A light bulb connected to the antenna jack of a radio is simple and effective method to test if your radio is transmitting. The instruction below explain how to test an HF Radio and optionally the SG-230 Coupler. Equipment Required: Any HF SSB and AM/FM Transmitter. SG-230 Coupler (optional) AC to UHF Connector Cable [see figure below] AC to Alligator Clips Cable (needed with Coupler) [see figure below] Light Bulb to AC Adapter [see figure below] Light Bulb; 75 to 200 watt, 120 to 220 VAC Radio Test Procedure: 1. Connect "AC to UHF Connector Cable" to the radio RF IN/OUT Connector. 2. Screw light bulb into "AC Adapter" 3. Plug AC Adapter and light bulb into "AC to UHF Connector Cable" that is attached the radio [see figure below] 4. Turn on the radio and set to CW mode and PWR to HI 5. Key "push to talk" switch on microphone, and observe the light bulb. The light should come on if the radio is transmitting. 6. Set power to LO 7. Key "push to talk" switch on microphone, and observe the light bulb. The light should come on if the radio is transmitting. Observe that the light is not as bright as step 5. 8. Set power to HI 9. Set the radio to A3H mode or CW and any carrier. 10. Key "push to talk" switch on microphone, and observe the light bulb. The light should come on if the radio is transmitting. Observe that the light is not as bright as step 5. 11. Set the radio to A3J mode 12. Key "push to talk" switch on microphone and talk into the microphone. Observe the light bulb comes on when you talk. 13. Set the radio to A3A mode 14. Key "push to talk" switch on microphone and talk into the microphone. Observe the light bulb comes on when you talk. Coupler Test Procedure: 1. Connect coupler to the radio and disconnect antenna from coupler. 2. Connect "AC to Alligator Clips Cable" to the SG-230 antenna jack. 3. Screw light bulb into "AC Adapter" 4. Plug AC Adapter and light bulb into "AC to Alligator Clips Cable" that is attached the coupler. [see figure below] 5. Turn on the radio and set to CW mode. Turn on the coupler 6. Key "push to talk" switch on microphone, and observe light bulb. The light should come on if the radio is transmitting. Note: The light bulb may not come on immediately if the coupler has not yet been tune for that frequency. The light bulb brightness is greatest when the coupler is tuned for that frequency.
