Callsign
Results 1 to 10 of 10

Thread: Transmitting AM on a 6m DIAMOND CP62 Antenna???

ad: l-AmericanRadio
ad: l-assoc
ad: l-innov
ad: l-ezhang
ad: l-hrd-1
ad: l-BCInc
ad: l-Waters
ad: l-gcopper
  1. #1
    Join Date
    May 2011
    Location
    Blackwell MO 63626
    Posts
    95

    Default Transmitting AM on a 6m DIAMOND CP62 Antenna???

    Is it possible to transmit AM on this antenna? My local club has a 6m AM net and I want to know if this is capable of transmitting on the AM side. I'm not sure and not experienced with AM transmissions..

    Greg D Isringhaus

  2. #2
    Join Date
    Feb 2003
    Location
    Wonderful WYOMING, Accept no substitutes.
    Posts
    3,119

    Default

    Antennas don't care about mode. As long as the SWR is good, it will be fine. AM,FM,SSB,CW Are all the same as far as the antenna knows.

    Brad
    "Life is just like ridin' broncs, its a battle". Chris ledoux

    Long live Steamboat

  3. #3

    Default

    No, no, no! If it's not an AM antenna, forget it.

    Of course the antenna couldn't care less about mode.

    However, it's a vertical. If the other stations in your local net also use verticals, it should be perfect. However, if they use horizontal polarization (beams, etc.) it may not work well at all. For local "direct wave" and even tropo propagation there is a huge disadvantage to running cross-polarization.

    Why not find out what they're all using?
    A government which robs Peter to pay Paul can always depend on the support of Paul.

    -- George Bernard Shaw

  4. #4
    Join Date
    Apr 2001
    Location
    Sutton NH
    Posts
    331

    Default

    Well, according to this:
    http://www.rfparts.com/diamond/pdfdo...structions.pdf
    The antenna has about a 1MHz wide BW. Tune the antenna for say 53MHz, and you may have issues if you are running on the lower end of 6m. Where is 6m AM these days?

    Also, it states that it is 500W SSB, and 200W FM. I forget how AM is spec'd out; is it total forward peak power; or dead carrier power? Regardless, the typical 100W (or 50W) home station would be fine; but certainly not at 500W carrier! [500W carrier would be what, 1500W at peak forward power? Each sideband being no more than one-half of the carrier power, that is, so as to avoid overmodulation.]

  5. #5
    Join Date
    Apr 2006
    Location
    Somerville NJ
    Posts
    128

    Default

    Quote Originally Posted by K0GDI View Post
    Is it possible to transmit AM on this antenna?
    I can't believe this question are you serious?

  6. #6
    Join Date
    Jan 2002
    Location
    harms way
    Posts
    8,346

    Default

    If you transmit am on that antenna you will rip the time/space continuum assunder! No really antennas don't care about what mode you use them for. They don't care about anything really. Kinda cold and heartless if you ask me. Now for a more rational response yes you can run am on that antenna, the more important question is does the antenna exhibit a low swr on the frequency you wish to operate at? If it does, everything's fine. If it doesn't, see if you can adjust the antenna to reduce the swr at your desired frequency.
    now with true viterbi decoder!

  7. #7

    Default

    Quote Originally Posted by KB1CKT View Post
    Well, according to this:
    http://www.rfparts.com/diamond/pdfdo...structions.pdf
    The antenna has about a 1MHz wide BW. Tune the antenna for say 53MHz, and you may have issues if you are running on the lower end of 6m. Where is 6m AM these days?

    Also, it states that it is 500W SSB, and 200W FM. I forget how AM is spec'd out; is it total forward peak power; or dead carrier power? Regardless, the typical 100W (or 50W) home station would be fine; but certainly not at 500W carrier! [500W carrier would be what, 1500W at peak forward power? Each sideband being no more than one-half of the carrier power, that is, so as to avoid overmodulation.]

    AM on 6 Meters is toward the low end of the band, just above the area normally used by SSB. 50.4 MHz may be about right. Tuning an antenna intended for AM operation to 53 MHz id dead WRONG. That's the FM region, at least here in the U.S. Some antennas may have a wide bandwidth, but that's a stretch.

  8. #8
    Join Date
    Aug 2004
    Location
    Des Moines, IA
    Posts
    5,496

    Default

    Quote Originally Posted by KB1CKT View Post
    Well, according to this:
    http://www.rfparts.com/diamond/pdfdo...structions.pdf
    The antenna has about a 1MHz wide BW. Tune the antenna for say 53MHz, and you may have issues if you are running on the lower end of 6m. Where is 6m AM these days?

    Also, it states that it is 500W SSB, and 200W FM. I forget how AM is spec'd out; is it total forward peak power; or dead carrier power? Regardless, the typical 100W (or 50W) home station would be fine; but certainly not at 500W carrier! [500W carrier would be what, 1500W at peak forward power? Each sideband being no more than one-half of the carrier power, that is, so as to avoid overmodulation.]
    500W of AM carrier would equate to 2000W PEP at 100% modulation (4:1 ratio).
    There aren't many ham radio amps that'll do that for very long before cratering.
    I have seen one homebrew amp that would do it on 160m but it is a former AM broadcast transmitter (5KW) "retuned" for 160m.
    It's the size of a telephone booth.
    CW is a manually controlled, message asynchronous, simplex chat mode used without FEC.

    "The democracy will cease to exist when you take away from those who are willing to work and give to those who would not." -- Thomas Jefferson

    DX Code of Conduct

    Registered Linux User #307249

    ACØH
    SPAR
    ARRL
    SKCC #215
    NAQCC #3441
    FISTS #11993


  9. #9
    Join Date
    Apr 2001
    Location
    Sutton NH
    Posts
    331

    Default

    Ah, ok, 4:1. I was thinking 3:1; what can I say? I came along long after SSB ruled the air.

    Anyhow, the antenna is low(er) power rated; and the bandwidth, *if set for the FM sub-band*, is not going to let one use AM down where it typically is used, unless if coax loss is decent; or if old-school tube gear is in use. Don't use an amp, and make sure the SWR is tolerable (may need to adjust the antenna, see the instructions), and go for it. Well, assuming you go this route, that is

    Good luck!

  10. #10

    Default

    The AM "calling frequency" on 6-meters has been 50.400 MHz for well over 6 decades.

    With 100-percent modulation you are limited to a maximum of 375 watts carrier on AM which produces 1500 watts peak power.

    Glen, K9STH

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •