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DaveMade M400 HG

Discussion in 'Amplifiers' started by Unionbro, Jul 22, 2018.

  1. Unionbro

    Unionbro New Member

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    I ran across a package deal from a fella that used to work on radios back a few years ago, probably more like 10 plus years ago judging from the stuff he had.

    Anyway, amongst the stuff, and there was a lot of "Stuff" There was a DaveMade M400 HG. It looks like its in decent shape, cant see where any smoke got out of it, but there could be some bad pills etc...

    I did notice right off that the TX out was not wired into the board, and there's a couple other random wires in the same area not hooked up.

    It looks like someone removed the Min/Max RF knob as well, I dunno why you would wanna do that, but apparently it made sense to someone. The Transformer is there, the Big ass Capacitor is there, two bridge rectifiers, all 4 pills the ferrite cores, and 90 percent of the circuitry looks intact.



    My question is does someone else have one of these that could take some internal photo's so I could get an idea of how it should be wired.

    Better yet if someone had a set of Schematics that would be flippin Awesome!

    I think with a little TLC i could get this old girl talking again, but yet I'm at a loss, because I never had one to know how it should be wired.
     
    Shadetree Mechanic likes this.

  2. Unionbro

    Unionbro New Member

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    Looking around online at a few pictures, it looks like the TX relay is missing... So I'd need to know the specs on that for sure. Not sure if this had a driver or if it's just a 4 pill driven by the radio, I see a space for a driver pill on the board, but its not tapped and has no evidence of one ever being installed here.

    And of course the RF Min/Max knob is missing, I did find something in the other boxes of "Junk" that looks like it could have been the removed knob, its mounted on a small board with a trimmer pot. But it could just be chance.
     
  3. Mustang 131

    Mustang 131 Well-Known Member

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    Never heard of a HG. Must be one of Joes boxes.
     
  4. nomadradio

    nomadradio Analog Retentive

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    The letters "HG" probably refer to the chinese supplier of these transistors known as "Hua Gao".

    I would strongly suspect that an amplifier that large with nickel-and-dime parts missing has blown RF transistors. No other good reason to snatch cheap parts from an expensive unit. If it's broke, who cares?

    Each pair of RF transistors (yes they look a little like a pill) has a short ferrite transformer at the input end, and a longer one at the output end.

    On the input-side (short) transformers, you'll see a small resistor with one end soldered to the input leg of the transistor. This is the flat lead soldered to the short ferrite transformer. That resistor will be visibly smoked or darkened from heat when those transistors fail in a particular but common way.

    More than one way for a transistor to go bad inside, but if you see damage to one or more of these resistors (one on each transistor's input), this means you probably need a complete set of those expensive transistors. Plus the small stuff that got robbed off it when it was in someone's boneyard.

    They must match, not so different from making a piston and rod balance the others in a race motor. Replacing only a few of the transistors runs the risk of mismatching the way they share the load, causing another one or more transistors to overheat and fail again. If you think you can match only the two bad transistors (for example) to the others, go for it.

    Buying a matched set of four is safer. And the harder you crank it, the more this matters.

    73
     
  5. 9C1Driver

    9C1Driver Sr. Member

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    If it has HG finals inside then someone has messed with it recently anyway. Ten years ago Toshiba finals were still plentiful.
     
  6. jessejamesdallas

    jessejamesdallas Sr. Member

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    Think everyone started using the HG's once the DEI's got discontinued... Last I herd Joe in NC was now using the HG's in his DM box's...He still uses the Toshiba's too, but the price of the box almost doubles...

    XForce went from Toshiba's to DEI's, then went to PP100's, but apparently now XForce is "no-more"...Lot's of guys placed orders with XForce, and looks like they got taken to the cleaners now...Lot's of un-happy campers can't even get a answer back from XForce or their money back...
     
  7. Mustang 131

    Mustang 131 Well-Known Member

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    Please tell, Zapco is MIA? Sounds like a new thread.
     
  8. 543_Dallas

    543_Dallas Sr. Member

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    Is Zapco the new Z-man? I read something about this on cbradioforum.com a month or so ago. A customer paid for an amp, never received it and couldn't get Arlyn to answer the phone. The forum admin tried contacting xforce and got nothing.
     
  9. undertaker

    undertaker Undertaker

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    Xforce is no longer selling amps. Look at there website..
     
  10. 543_Dallas

    543_Dallas Sr. Member

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    These types of builders and vendors have been known to temporarily take the amplifiers off of their website for one reason or another. The nature of selling illegal radio gear I suppose.
     
    undertaker likes this.
  11. jessejamesdallas

    jessejamesdallas Sr. Member

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    Found out what happened to XForce...apparently Arlyn had some health issues back first of the year and had to have stents put in some arteries so was in and out of the hospital for a while...Then later he had some more problems with the stents and went back into the hospital...This whole time tho orders were still being placed, and people calling and emailing him about orders, so he got real far behind and backed-up...From what I gathered off the fb site he took down all the info on placing orders till he can get the orders he has built and shipped...

    That's what was posted back at the end of August...Not sure if he's doing any better or not, but since he didn't take down the web.site I'm assuming once he gets caught back up, then you will be able to place orders again...
     
    Shadetree Mechanic likes this.
  12. Mustang 131

    Mustang 131 Well-Known Member

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    Too bad, wish him the best.
     
  13. w9cll

    w9cll W9WDX Amateur Radio Club Member

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    They need time to pack the Winnebago and move to the next location.
     
    undertaker likes this.
  14. 9C1Driver

    9C1Driver Sr. Member

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    X-Force has been around since 1998, I hope he can get through his medical issues and come back strong.
     
  15. 543_Dallas

    543_Dallas Sr. Member

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    It was a different owner back then. I have some xforce amps from around 2006 and the quality was very good. The current owner took over 3 or 4 years ago. I had high hopes for him but the quality went down the toilet. The workmanship and qc on the ones I've saw has been disappointing.
     

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