When is more than a few watts power needed?

Discussion in 'VHF/UHF - 50Mhz and Beyond' started by N0PKG, Oct 27, 2015.

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  1. N1UV

    N1UV Ham Member QRZ Page

    If the bird has a linear transponder and you use too much power, it will, in effect, limit the left over downlink power for other users of that transponder (not to mention eating into the power budget). This obviously won't apply for FM-only transponders.
     
  2. K8JD

    K8JD Ham Member QRZ Page

    Line of Sight work
    Several decades ago when I considered 2M FM as a serious form of radio, I ran a 140W amplifier and a 7 ft tall gain antenna on the roof of my station wagon to talk, mostly, on simplex.
    I often had QSOs with ops who kept telling me we were going to be out of range soon but I would tell them just hang on with me a while. We would go far beyond where the other guy had ever talked on simplex before !
    Other times I would answer another op who had a handheld and "rubber duck" ant in his house. His reception was so poor with that little radio and antenna it was hard to get back to him when I could hear his 2W clearly ! Never could determine if it was local interference or just a poorly aligned receiver in his talkie ?
    Lately I listen to the VHF and UHF simplex "calling" channels on my scanner receiver and it seems like everyone is stuck in the repeater habit and only use simplex for private "secret" comms where they never expect to be heard by anyone else :D
     
    Last edited: Nov 3, 2015
    W0GSQ likes this.
  3. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I've experienced that also and think it's a combination of "newer" hand helds having receivers that cover DC to daylight so they're very prone to interference and desense from almost anything, and the multitude of home electronics products that can generate such interference.

    It used to be better when hand helds only covered the 2m band and couldn't receive anything outside the 2m band -- they often had helical resonators to restrict sensitivity outside the band and were much more "sensitive" inside the band as a result.
     
  4. N0PKG

    N0PKG Ham Member QRZ Page

    Lots of interesting replies, thanks folks!
     
  5. W6KCS

    W6KCS Ham Member QRZ Page

    That would sound noisy, but would probably be copyable. 0 dBm minus a few dB for a small portable antenna, minus 94 dB of path loss puts the signal down around -100 dBm at the far end, which is only about 2 microvolts.
     
  6. W0AAT

    W0AAT XML Subscriber QRZ Page

    Out here on the prairie where repeaters are 30-60 miles apart I run 50 watts mobile and in the house. On 2m SSB how much power is enough? 1kw comes in handy...
     
  7. K2HAT

    K2HAT QRZ Volunteer Volunteer DX Helper QRZ Page

    As other folks said, if you are farther away from your target, simplex or a repeater; you might need more power, even with a good antenna
    to be heard. I talk on 2m simplex at times with some other local folks, and as I live in a valley, often have to go to 40 watts or more.
     
  8. K3XR

    K3XR Ham Member QRZ Page

    As often happens in a thread where power is included in the topic was waiting for someone to say you are required to use the minimum power and even quoted the regulation but conveniently left off the part about "desired communications" as KC9UDX accurately points out.

    I don't want to strain my ears to hear a signal if increasing power will result in more comfortable listening.
     
  9. K8MHZ

    K8MHZ Ham Member QRZ Page

    97.313 An amateur station must use the minimum transmitter power necessary to carry out the desired communications.

    That's a great point. The rule is so ambiguous that it shouldn't even exist. If the intent of the rule is to curb interference, causing interference is already against the rules. I think the maximum should be the rule and leave it at that. Any lawyer would have a field day with the term 'desired communications'.
     
  10. K3XR

    K3XR Ham Member QRZ Page

    Writing laws/regulations that are ambiguous helps keep lawyers in business and the courts busy.
     

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