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80 meters AM

Discussion in 'Discussions, Opinions & Editorials' started by KA0SOG, Oct 6, 2012.

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  1. KA0SOG

    KA0SOG Ham Member QRZ Page

    Recently saw a post about the Ensor Farm Museum putting a restored 1918 transmitter on the air on or around the 8th of December. I got motivated to play with a little 80 meter AM and was curious if anybody had suggestions. I run with a Yaseau 950 and a Hustler multiband verticle. Any suggestions from the AM community out there? :confused:
  2. K7GFH

    K7GFH Ham Member QRZ Page

    I am in the same boat you are. I would like to give it a try but I have not finished my 101-EE. Currently using my 450-D. I have heard that most of the groups use older AM equipment which have much better audio quality on AM. I listen a lot on 3885 but have never transmitted, not sure if newer equipment is looked down upon.
  3. N2EY

    N2EY Ham Member QRZ Page

    Small but important bit:

    On the 3.5 to 4.0 MHz amateur band, the part where voice is allowed in the USA is referred to as "75 meters" and the part where voice is not allowed is "80 meters". So 3.5 to 3.6 is "80" and 3.6 to 4.0 is "75".

    This isn't just casual ham jargon - FCC Part 97 spells it out that way.

    73 de Jim, N2EY
  4. K9ASE

    K9ASE Ham Member QRZ Page

    AM is alive and well in that portion of the band. I've never heard anyone critize a well modulated "modern"radio.
    I've even heard guys using Flex radios. There is also AM action on 40M @ 7.295 Here's a good link for AM stuff.
  5. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    New ham gear is not looke down upon by the AM crowd at all. Since using new gear isn't very "experimental" or "homebrewed," there's not as much to talk about -- and the AMers love to talk about what equipment they've brought back to life and modified to work better...that's a lot of the conversation.

    However, nobody will care if you use a brand new solid state multimode rig, as long as you've set it up properly for AM. A lot of AM enthusiasts have good stuff and good ears and will help you make adjustments until it does sound good.

    An FT-450D will sound much better on AM than the old FT-101EE will. There's a world of difference: With the new rig, AM is generated via DSP and can be absolutely "perfect" if you do everything right. With the older rig, it's not, and no matter what you do it won't be perfect AM.

    Remember "full" AM PEP is four times carrier power, so if you use a 100W output rig, the carrier should never be more than 25W, to allow for full modulation that sounds good. Often, the adjustments for things like high and low frequency rolloff need to be changed for AM (compared with SSB), and TX bandwidth should be cranked up wider; and usually, a speech processor is a bad idea for AM, even if it works great on SSB.

    Jump in and get some reports!
  6. KO6WB

    KO6WB Premium Subscriber QRZ Page

    Yes they do Jim, but wavelength is just a generalized term and not necessarily the letter of the law. Example; 3.6MHz is 83.33 meters. It's not 75 meters until you get to 4MHz. 80 meters is 3.75MHz. The bottom of the 80/75 meter band is about 85.71 meters at 3.5MHz. We quit using the wavelength to measure frequency a long time ago. It's just a generalized measurement so everybody is talking on the same page. The FCC uses these terms to relate to amateurs and get the message across clearly and easily where you are allowed to operate and where you're not.
    It's just small stuff so don't sweat it. Just don't operate improperly.
    Have fun
  7. N3IFD

    N3IFD Ham Member QRZ Page

    - 003,880,000 Hz
    - 150 Watts P.E.P.
    - A3E(AM)
    - 060 % Average Modulation
    - 20 dB Processor Compression
    - 3,000 Hz(1,500 Hz X 2) Resultant Passband via
    audio, on rig, set to "high-pass"

    - 080 Meter Band Dipole(140 feet long!) with it's
    ends bent down(the last 16 feet!) up 38 feet in
    the air at it's feedpoint(The total horizontal length
    is 108 feet.).

    These suggestions might be a bit controversial. The operator making these suggestions IS controversial. However,
    I recommending them because I myself would do them also. It makes good sense.

    I operate on: 040 Meters @ 007,290,000 Hz; 025 Watts P.E.P.; A3E(AM); 060 % Average Modulation; 20 dB Processor
    Compression; 3,000 Hz(1,500 Hz X 2) Resultant Passband via audio, on rig, set to "high-pass"; with a 040 Meter Band
    Dipole at half the overall dimensions as the afore mentioned 080 Meter Band Dipole. I use a Kenwood TS-570D
    Transceiver with it's stock microphone.

    I AM HEARD WELL within 400 miles during the day, 1,000 miles at night.


    P.S.: The mathematics behind the suggestions are long and boring, but available if you need them.
    P.P.S.: It's true. The F.C.C. distinguishes between the 080 Meter Band(003,500,000 Hz =to= 003,600,000 Hz)
    and the 075 Meter Band(003,600,000 Hz =to= 004,000,000 Hz).
    Last edited: Oct 6, 2012
  8. W8ZNX

    W8ZNX Subscriber QRZ Page

    pray tell what with the extra zeros in front

    by the way

    would not 060% modulation = 6% modulation
  9. W8ZNX

    W8ZNX Subscriber QRZ Page

    to me
    calling the phone part of the band 80 or 75 is pretty much interchangeable

    sometimes i call the whole band 80 sometimes i call the phone band 75

    anybody wanting to argue about it is just nit picking

    AM on 80
    many modern xceivers sound fine on AM

    the days when some of the big gun AM ops would say
    go way boy and come back with a real AM rig are over

    run what you got

    dit dit
  10. KC5FM

    KC5FM Ham Member QRZ Page

    You would be welcome on AM with your current setup.

    Check out the AM frequencies used and the monthly AM radio net on the first Wednesday.

    Hope that helps.

  11. WS4B

    WS4B Ham Member QRZ Page

    I mostly agree with that. There are SOME who may give you a hard time if they sense you are using an under modulated "rice box", but they are now in the minority. The vast majority will help you to get the FT-950 sounding as good as possible.

    Certainly don't restrict your desire of AM just to 75/80. AM can be found on every band excluding the WARCs. (it is occasionally heard on 17)

    I invite you and everyone else to join us every Monday evening beginning at 7:45 PM eastern on 14.330 +/- for a very casual weekly AM net where we average about 12 check-ins. I hope to work you sometime soon on Angel Music.
  12. KY5U

    KY5U Ham Member QRZ Page

    I corrected you above according to the NVEC. Also the ARRL Band Plan calls 3.5 to 4.0 "80 Meters" and yes, it's very misleading. Good luck on the FCC site finding 97.301. Part 97 takes you to the GPO which shows something else.
    Last edited: Oct 6, 2012
  13. KY5U

    KY5U Ham Member QRZ Page

    Also on the subject at hand (AM), if you have a good antenna system then by all means drop your call in. Most of the people you hear either have good antenna systems, run power, or both. It can be challenging to be heard with under 100w otherwise.
  14. AB8KT

    AB8KT Platinum Subscriber Platinum Subscriber QRZ Page

    I am quite active on AM (mainly on 75 meters) and I have never heard anyone looked down upon because they were running a modern solid state rig. I work people all the time running modern rigs. I probably worked two or three last night. I know I worked a guy last night running an IC-718. The contact before that was running a solid state rig (I don't remember which one) and we spent a few minutes with him making adjustments to his carrier as well as his audio settings. Flex radios are popular on AM as well. It's true that most people are running vintage tube gear and it's also true that a lot of the discussion centers around vintage rigs and working on vintage rigs, but that doesn't mean that modern solid state rigs arn't welcomed with open arms.

    I have been surprised at the number of stations using low power and it seems to work OK to me. Not only "modern" rigs with 25 watts of carrier, but also vintage novice type rigs as well as the occasional homebrew solid state rig running 10 or 30 watts carrier. Just as a guess based on the people I work, I would say that at least half the people I work and possibly a majority are not running big power. I occasionally get on with my Retro 75 running 2.5 watts of carrier and usually work someone.

  15. KL7AJ

    KL7AJ Ham Member QRZ Page

    I'd be glad to work you on 80 meter semaphore! :)
  16. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    I've checked into the local AMI net on 75m (3870 or thereabouts) many times, with different rigs.

    I've used my homebrew (1966 vintage) 4-250 modulated by P-P 811As and lots of tweaking. It runs about 100W carrier power and 400W PEP.

    I've also checked in using my Ten Tec Jupiter at 25W carrier power and 100W PEP, and most can't even tell the difference. In reality, I get more "incredible audio!" compliments with the Ten Tec.:p

    A lot of guys on the AM nets are using very old vintage gear that really isn't very good, it's just fun to use. I can run more power, with far better modulation, with my Jupiter than someone can with a DX-60A. I can run "almost" the same power with the modern SS rig as a Ranger, but my audio is generally better since the Ranger doesn't have a built-in audio equalizer like the Jupiter does.

    My even older TS-850S sounds good on AM, too. The only rig I own which isn't very good on AM is my TR-7. It can run more power than most modern SS rigs, but its transmitted bandwidth is just too narrow and it tends to sound bassy.

    Most modern DSP rigs can be made to sound better than the old "heavy iron" boat anchor gear can, although maybe not as much power.

    The cool thing about the AMI nets is a lot of guys are running quite low power with 1950s-era gear and it's fun to hear them experimenting with it. A few are running really big stuff, like kilowatt-level AM BC transmitters with excellent modulation, and they can sound great but they're really in the minority.

    I've found the "AM crowd" is very open to anyone who wishes to join them and will help coach newcomers to sound better.
  17. K9ASE

    K9ASE Ham Member QRZ Page

    a friend/elmer of mine has a Collins 820 Broadcast transmitter we've resurrected in his basement. He uses it for 75,160,and 40 meter AM
  18. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    The BC stuff is pretty common on AM, as it's not expensive although heavy and takes up lots of room.

    Many locals here use Collins-GE-RCA-Gates BC stuff at least on 160 and 75. I don't know if they have converted it to 40m also, but maybe.

    Old BC stuff isn't expensive, but you need space! And in some cases, maybe a fork lift.
  19. K9ASE

    K9ASE Ham Member QRZ Page

    Trust me I know they're heavy even with the transformers removed. One thing I will say though is, "If you ever wondered about those Miracle Movers you see on TV,they work." :eek:We put those under the corners of that Collins and it made moving it around the basement a lot easier.
  20. AC0FP

    AC0FP Ham Member QRZ Page

    AM transmitters do consume a lot of power. Many years ago I worked in avionics designing solidstate AM transceivers, they put out 20 watts carrier power and measured 80 watts PEP. The transmitter used a class C series modulator and only had 2% distortion. To bad the receivers used the classic AM diode demodulator with about 10% to 15% distortion. They could of used a "synchronous detector" (like used in SSB and similar to those used in FM) but it cost to much, even if it gave 1% distortion.

    Most amateurs don't understand their 100 watt SSB PEP rigs, when modulated with two audio tones only produce 50 watts average (carrier) power.

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