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RocketBox HD500 w/9530 FETs

Discussion in 'CB and Export Equipment and Accessories' started by CB590, Jul 27, 2019.

  1. CB590

    CB590 W9WDX Member

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    Anyone have any input on these units.

    Says can do HD input up to 50w..

    Uses Palomar 9530 FET x4

    Ratings say upto 25w in with 100w out

    Builder says upto 55 amp draw. Has auto SSB like old Palomar units.



    Units are $370 shipped. (About $120 less than a TS500HDV..)

    Was entertaining for my AT-6666 as it does 40-50w peak.. mainly SSB.

    Builder says 50w input for max output and should reach 450-500w.. says AM dk is 2-5w and swing up from that.

    They also now offer a 2x4 LD model for $430 or so..

    Screenshot_20190727-183355~2.png Screenshot_20190727-183522~2.png
     
    Shadetree Mechanic likes this.

  2. Shadetree Mechanic

    Shadetree Mechanic 808 On The North Side of Dover

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    I wonder how hard it would be to turn the 2x4 into a straight 6?
     
    rabbiporkchop likes this.
  3. ExitThirteen

    ExitThirteen Grumpy and Cranky

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    Junk... those mosfets drop output when they get hot, you'll start out at 400-500W, but as you talk on it and the mosfets get hot they will slowly reduce output, talk on it for an hour and you'll only be doing about 250-300W or so PEP. Don't buy one. Seriously.



    ~Cheers~
     
  4. jkp1

    jkp1 Member

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    I'm kinda getting itchy to try an amp. I'm kinda torn between a Texas Star 500 and an Ameritron 500.
     
  5. CB590

    CB590 W9WDX Member

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    I already had a TS350 and sold it due to truck repair.

    I am leaning towards 400-500w myself.. the TS500 is like $475 all day.. the 60-70amp PS to run it is like $180 minimum though..
     
  6. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    That's the beauty of FETs. They get hot and "Throttle Back" as it were. If your car has a speedometer that reads up to 150 mph are you going to drive everywhere @ 150? One of my bikes had a speedo that read up to 180 mph and I guarantee it never got over 135 on a track.
    I would go with the Ameritron 7 days a week.
     
    #6 Tallman, Jul 30, 2019
    Last edited: Jul 30, 2019
    rabbiporkchop likes this.
  7. CB590

    CB590 W9WDX Member

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    I'm wondering how bad the RocketBox would be for the light SSB aka quick contacts like I do?

    I don't rag chew that's for sure.

    My # yelling CQ and then waiting.. then a response from say 357.. then me confirming with 357.. maybe a 15 second qso about weather, usually not..

    Then a 2-3 minute wait till the next volley..
     
  8. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    Probably no problem.
     
  9. rabbiporkchop

    rabbiporkchop Sr. Member

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    First one I saw the input tune was all screwed up. Since they use mismatched mosfets they generate lots of distortion. If they were built correctly they would have lots of potential. Building them correctly means the cost would have to go up I highly doubt he's willing to do that.
     
    Shadetree Mechanic likes this.
  10. Shadetree Mechanic

    Shadetree Mechanic 808 On The North Side of Dover

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    So then it's like MFJ products. A project in a box......
     
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  11. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    Matching mosfets is not critical as bipolars. That amp is just like all of the others.
    If you put a garbage in you get garbage out. Radios that have been tuned for "Ghost Watts" will always sound like $h1t. If the harmonic filters have been screwed up the input SWR will be high.
     
    NZ8N and TheRealPorkchop like this.
  12. CB590

    CB590 W9WDX Member

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    I'd entertain the RM 7505v with 4 of the MRF455..

    Turn my amp to low power and swing 1-18w on SSB mode with the 6666 into it..

    The 7505 is like $210 all day..

    Thoughts on that for a choice?
     
  13. 9C1Driver

    9C1Driver Sr. Member

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    If you go Texas Star look for an older used one in good shape with Toshiba finals. New ones will probably have the HG finals or maybe even the DEI's.
     
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  14. rabbiporkchop

    rabbiporkchop Sr. Member

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    Probably more critical. They need to switch in unison. They won't if not matched.
     
  15. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    I disagree completely. FET's do not have the negative temperature coefficient like the bipolars. There is very little to match other than the part numbers. The Rds on does not vary much often less than 10%. Most of the time less than 5%. The input capacitance does not vary very much either. The Vgs varies some but with a spread of less than .3 volts it is hard to get fanatical about that.
    Using a radio that has been SCREW drivered is more of a problem.
    Messing with the harmonic filters for extra output is just plain stupid.
     
    #15 Tallman, Aug 3, 2019
    Last edited: Aug 3, 2019

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