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  1. harryr

    frequency measurement

    how many cycles of a constant frequency sine wave are counted before one determines the frequency of the signal? one cycle? how about measuring the time it takes to go from 0 volts to the first peak and multiplying the time by 4 to get the time for a complete cycle. the frequency is then the...
  2. harryr

    do harmonics exist?

    FMRadio -thanks for your reply. I feel that I have not defined my question well enough. Many respondents have reminded me about the Fourier transform and how to use sine waves (odd frequencies and phase shift management ) to "create" a square wave. I agree with that. No one has yet explained how...
  3. harryr

    do harmonics exist?

    VE1BLL-- thanks for your input. My question is, How does the signal generator make square waves? If it is synthesized from sine waves and the equipment "leaks" RF energy, you can measure the different freuuencies.
  4. harryr

    do harmonics exist?

    Comcokid:Thanks for your reply. Regarding the square wave generator you mentioned, does it make square waves out of sine waves? If it does I agree that the "harmonics" exist. I believe these "harmonics" are the sine waves that are used to make the square wave. My question is-- How does a battery...
  5. harryr

    do harmonics exist?

    S.Gunslinger Thanks for your response. I would like to make sure you understood my question. I'm not doubting your response but if that's true, I need you or someone to answer another question. Clarification of my previous post, if needed. The time domain waveform that I have was not created by...
  6. harryr

    do harmonics exist?

    I understand that I can do a Fourier Transform on a waveform in the time domain to identify frequency components which can be combined to reconstruct the waveform in the time domain. Now, say I have a component in the frequency domain at for example, 30 MHz. If I excite the box that is...
  7. harryr

    alternators in parallel

    Aviat- thanks for the information. I'm trying to find out if there is a weight/reliability benefit with either method and if someone has done a study and published a paper. I don't want to reinvent the wheel.
  8. harryr

    alternators in parallel

    Does anyone know of an aircraft that has two or more ac generators (alternators) that are operated in parallel? That is, as opposed to each alternator feeding it's respective bus and then tying the busses together when one alternator fails. Military or commerical, fixed wing or rotary wing...
  9. harryr

    rotor modulation

    I am on a program that has a vhf fm (30-88 MHz) antenna installed on a helicopter on the vertical next to the tail rotor and am experiencing a rotor modulation effect that causes an uneceptable amount of distortion. any one have this experience and what can be done?
  10. harryr

    VSWR

    Logbook Thanks very much for your explanation. Appreciate it.
  11. harryr

    VSWR

    logbook, thanks for your response. However, isn't it true that if I add a series resistance I will cause a "resistance bump" that is, a change in resistance at that point and a reflection along with increased insertion loss and a greater VSWR? Appreciate your comments.
  12. harryr

    VSWR

    logbook- Thanks for your reply. I do have a Wiltron scaler network analyzer. The cable spec says 1.4 VSWR for each of three cables. The VSWR for the connectors are not specified. I measured the VSWR for each of the three cables and got the following (for example) at 10 GHz: cable 1 1.1 cable 2...
  13. harryr

    VSWR

    I have three coax cables between a radio and the antenna with a connector at each end and two connectors in the middle. I know the VSWR of each cable (from the spec sheet) Each cable is 50 ohms assuming a 50 ohm load at the antenna end, how can I calculate the end to end VSWR? each cable has a...
  14. harryr

    Door switches with lamps indicator

    Melone/ Mulderm Melone: It would be nice if we could attach a schematic to this post. Is there a way to do that? I think we are all looking at different wiring diagrams. If I understand the wiring diagram and your solution, if the first light goes out, they will all go out since the the...
  15. harryr

    Door switches with lamps indicator

    How far apart are the door switches? Are the series switches closed and they open when a door opens or are they open and then close when a door opens?
  16. harryr

    Electrical Static on Aircraft

    aircraft use trailing edge(wings,rudders,flaps,etc) to mount devices called static wicks which are flexable, carbon filled, small diameter tublar devices with many small hair like whiskers at the end that is opposite the attachment point. Helicopters attach these to the main and tail rotors in...

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