1. You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

Need some expertize opinion

Discussion in 'Amplifiers' started by Limeybastard, Aug 9, 2017.

  1. Limeybastard

    Limeybastard
    Expand Collapse
    Active Member

    Joined:
    May 29, 2017
    Messages:
    558
    Likes Received:
    70
    Can someone take a look at this amp for me and tell me what they think, I see a lot of cuts and joins in the psu cables, is this normal? I contacted the seller he seems OK. It looks well used, he claims hes had it for a while and just changed brige rectifiers or something a few times on it.

    http://www.ebay.com/itm/Fatboy-Amplifier-/222601096205?hash=item33d40f2c0d:g:89sAAOSwvv9ZgklJ


     

  2. nomadradio

    nomadradio
    Expand Collapse
    Analog Retentive

    Joined:
    Apr 3, 2005
    Messages:
    819
    Likes Received:
    363
    No good for sideband. Built as AM-only.

    Never mind the switch marked "SSB". That's an outright fraud.

    73
     
    bob85 and Limeybastard like this.
  3. Limeybastard

    Limeybastard
    Expand Collapse
    Active Member

    Joined:
    May 29, 2017
    Messages:
    558
    Likes Received:
    70
    How can you tell? cheers
     
  4. Robb

    Robb
    Expand Collapse
    Yup

    Joined:
    Dec 18, 2008
    Messages:
    10,153
    Likes Received:
    2,002
    Just a FYI limeybastard; biasing is one electronic concept that pays to understand if you are considering amps. Like kicking the tires on cars - sorta.

    In a nutshell, biasing is the voltage feed control over the output power 'pills'. They need to get it at a specific rate - or curve - to give the pills a better distribution of power output tracking the output of the radio.

    FM radio output requires a 'C' type of biasing - which is what most AM operators use when they should be using 'B' type amp biasing. AM only radios should be used with B biased amps; however they don't know the difference - it seems. SSB requires 'AB' type of biased amps.

    If you have a radio that has SSB mode; then AB biasing is required to track its output in a linear fashion. If you use an AM only radio; then a B biased amp is best. Most of the CB amps on the market are 'C' biased; and not best for SSB-type radios with AB outputs. The Fatboy is C; Texas Stars are AB, while XForce are B class.
     
    #4 Robb, Aug 9, 2017
    Last edited: Aug 9, 2017
  5. Limeybastard

    Limeybastard
    Expand Collapse
    Active Member

    Joined:
    May 29, 2017
    Messages:
    558
    Likes Received:
    70
    Yeah, I think Im done looking for amps , think Ill just pull the cord and get a run of a mill TX DX500 or 1600, probably DX500 and run it about 200W tops pep. Common sense says that getting the 1600 texas star is is going to introduce another whole ball game to the situation, better coax, better antenna situation, better PSU.. More add ons needed.
     
  6. Tallman

    Tallman
    Expand Collapse
    W9WDX Amateur Radio Member, KW4YJ EXTRA class

    Joined:
    May 1, 2013
    Messages:
    1,532
    Likes Received:
    700
    Power supply issues easily fixed. Buy one or two of these 50 amp units.
    [​IMG]
     
  7. Limeybastard

    Limeybastard
    Expand Collapse
    Active Member

    Joined:
    May 29, 2017
    Messages:
    558
    Likes Received:
    70
    Job done, I bought a brand new 500v from ebay. You know, the seller that sells it then tells you to fuck off should a problem occur on first usage ;-)
     
  8. StrangeBrew

    StrangeBrew
    Expand Collapse
    Well-Known Member

    Joined:
    Aug 15, 2011
    Messages:
    427
    Likes Received:
    287
    Not sure what the one in the OP is but Fatboy has made AB amps in the past.
     
  9. Robb

    Robb
    Expand Collapse
    Yup

    Joined:
    Dec 18, 2008
    Messages:
    10,153
    Likes Received:
    2,002
    Not very familar with FB's either; but they are known for competition style C class amp. If they do AB biasing; then it is a further customization - IIRC. I'd be more impressed with them if they did it B class for AM only radios and not prep them for +20v operation . . .
     
  10. Klondike Mike

    Klondike Mike
    Expand Collapse
    Well-Known Member

    Joined:
    May 31, 2010
    Messages:
    523
    Likes Received:
    142
  11. StrangeBrew

    StrangeBrew
    Expand Collapse
    Well-Known Member

    Joined:
    Aug 15, 2011
    Messages:
    427
    Likes Received:
    287
    I have no use for a class C box myself, but we're not who he's building these for. His primary market is competition amps for keydown use.

    At least he does have better biasing available as an option, that's more than most of these guys do.
     
  12. w9cll

    w9cll
    Expand Collapse
    W9WDX Amateur Radio Club Member

    Joined:
    Jan 19, 2013
    Messages:
    2,780
    Likes Received:
    1,385
    100w and a decent antenna is all you need.
     
    Riverman71 likes this.
  13. Tallman

    Tallman
    Expand Collapse
    W9WDX Amateur Radio Member, KW4YJ EXTRA class

    Joined:
    May 1, 2013
    Messages:
    1,532
    Likes Received:
    700
    Who told you that?
     
  14. Limeybastard

    Limeybastard
    Expand Collapse
    Active Member

    Joined:
    May 29, 2017
    Messages:
    558
    Likes Received:
    70
    Indeed, hence the 500V, 100W?
     
  15. 543_Dallas

    543_Dallas
    Expand Collapse
    Sr. Member

    Joined:
    Jul 25, 2011
    Messages:
    1,148
    Likes Received:
    1,091
    100 watts AM? As in carrier? The Tejas Star 500 will fit the bill nicely. ;)
     

Share This Page