• 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.

Inside an XForce 200HD amp

M0GVZ

Sr. Member
Oct 18, 2011
1,790
1,597
173
Posted on Reddit.

Would anyone care to point out the problems? No way in hell would I ever buy anything from that company....

sBKwOCT.jpg
 

The problem is you are looking at it through British eyes expecting to see a neat factory manufactured board with clean soldering, correct impedance ratios in the transformers,
bias circuit,
These davemade clones have none of that & run with horrible efficiency on stock voltage but they will kick an rm500's ass in a keydown.
 
These davemade clones have none of that & run with horrible efficiency on stock voltage but they will kick an rm500's ass in a keydown.

Is that before or after its set on fire because there's no fuses, no protection diodes etc?

Its truly shocking. Its the kind of construction style you find in Radcom's "home brew" segment. Worst part is that they're charging the same price as we pay over here for something that looks like this:

RMKL400005.jpg
 
I wouldn't buy a class C competition box either, but we're not the guys that these are being built for.

You have to keep in mind that these things are built for competition, it's not supposed to be a part of a ham shack. The classes in a competition are based on how many transistors the box has, and the goal in the build is to get as many watts out as possible with the number of pills specified for the class. Anything that does not contribute to the goal of putting more watts into the air than the guy lined up next to you only gets in the way. These boxes do what they were designed to do quite well.
 
Throw in some regulated biasing with thermal tracking and it's not a bad little amp. It does have forced air cooling. Granted it doesn't have output filtering. But as said these were built/ designed for competition use. Strictly key downs. But a lot use on 11 meters day in and day out. They usually hold up to abuse.
 
  • Like
Reactions: tecnicoloco
Ten years ago I messed with a 200HD, it was a stout little box that got great on air reports. One night I was hammering away driving it with my Delta Force, a local said it sounded so good he gave me more then I paid for it on the spot. I then bought a Magna Force 350 to replace it.
 
  • Like
Reactions: Crusher
Is that before or after its set on fire because there's no fuses, no protection diodes etc?

Its truly shocking. Its the kind of construction style you find in Radcom's "home brew" segment. Worst part is that they're charging the same price as we pay over here for something that looks like this:

RMKL400005.jpg

The wiring to the amp can cause a fire if not fused at the battery. Unless someone gets careless and leaves a gasoline soaked rag or pile of dry leaves in that amp nothing is going to burst into flames.
 
  • Like
Reactions: tecnicoloco
MOGZV,
The idiot diodes in RM's are almost useless, you are a very lucky chap if reverse polarity does not take out the pa transistors,

The fuse holders & fuses don't hold up to the current the amp draws @ full power fm which is almost 50w less that RM claim & 150w less than they claim for ssb output,
people pester until i give in & pay me to remove the fuse holders in rm's & fit a correctly rated inline fuse,

Trying to squeeze out what RM claim on FM results in feedback resistors getting so hot they burn or fall out of the board,
They also pester & pay me to swap the 2w resistors for 5w resistors,

The kl400 is really a 100w amp, at that level everything holds up and they are reasonably linear,
They look pretty and work ok if used sensibly, The dave clones are fugly no doubt, making them pretty won't improve how many people you can talk over,

I have keyed a very similar amp on 18-19v against mates trying their best with their RM KL500'S, I have never lost a keydown.
 
Bob85 and DainBramage....

I'm not saying the RM amplifiers are good stuff, in fact they're also a stinking pile of shit I would never buy for the reasons Bob85 has said but the standards of construction and the fact they've at least attempted to put in basic fundamental safety in comparison to the Xforce is the point I was trying to get across.

Yes the Xforce is probably aimed at the keydown mob but people will buy them for normal use because they do well in keydowns. All that crap you complain about on the bands is from people using amps like these.
 
I don't get why people buy these things for normal use on stock voltage either,
They were made for a purpose and do surprisingly well for that purpose,

For anything other than that purpose id use a conventionally designed class AB amp that runs with better efficiency on stock voltage,

If you want EXTREME dirty try a palomar/boomer.
 

dxChat
Help Users
  • No one is chatting at the moment.
  • dxBot:
    Tucker442 has left the room.
  • @ BJ radionut:
    LIVE 10:00 AM EST :cool:
  • @ Charles Edwards:
    I'm looking for factory settings 1 through 59 for a AT 5555 n2 or AT500 M2 I only wrote down half the values feel like a idiot I need help will be appreciated