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Rocket Box 500HD Mosfet Amplifier

AK #5

Well-Known Member
I Support WorldwideDX.com!
Oct 31, 2014
324
325
73
Murray KY.
A friend of mine just gave me one of these.
Never used a Mosfet amp before, but I hear they're not as forgiving as a regular transistor amp.
Anyone else tried one of these?

hd500.jpg
 

A friend of mine just gave me one of these.
Never used a Mosfet amp before, but I hear they're not as forgiving as a regular transistor amp.
Anyone else tried one of these?

View attachment 72516
A friend I speak to regularly was on a quest to find a clean class AB amp and bought one of these. It is the worst of all of the 5 amps he bought. Apart from that, I can't say anything else.
 
I can’t find any of the others, I must be searching wrong. I did find this link but the 500 is out of stock.

 
The box seems to play nice with my new Washington. But not so good on AM, because I have to turn down the RF power to get 4-7W input drive, so the radio doesn't have enough PEP to drive it and get full power. About 550 plus on SSB though.
 
That's the high drive version.

"Dead key 2-4 watts Max. AUTO SSB 400-500 watts

Swing 50 to (80 watts max for output). Remember this unit will output when you transmit. DRAWS 50 AMPS.

SWR NEED TO BE 1.1 NO MORE THAN 1.5"

 
A friend I speak to regularly was on a quest to find a clean class AB amp and bought one of these. It is the worst of all of the 5 amps he bought. Apart from that, I can't say anything else.
Clean? As in not dusty? Or did you mean sampled to an analyzer and you saw third order harmonics higher than acceptable? None of these off the shelf amps have output filtering. For fixing/testing/building these type of amps I picked up a copper version of one of these:


There's no moving parts. They need some Electro-Wash on the SO239s and they work.

If the amp sounded like crap, it was overdriven. These rocketbox, and a lot of other brands as well, state a max input power in PeP. Problem is most people don't have a meter that does PeP correctly. A true PeP circuit requires power (voltage). If your meter works on PeP mode without batteries or other power, it's not really an accurate reading.

These HD500 models are a 0x4, straight thru input, your radio is the driver. The LD500 are 2x4. 2 drivers into the finals. With a decent LPF, I like these amps, especially th HD versions.
 
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A friend of mine just gave me one of these.
Never used a Mosfet amp before, but I hear they're not as forgiving as a regular transistor amp.
Anyone else tried one of these?

View attachment 72516
I have one and I love it! After I put a fan on top of it, have it turn on with the AMP while using LMR240 coaxial with an sirio antenna with SWRs set at below 1.5 while using common mode choke a foot from the antenna I am able to comfortably talk skip all day long. The coaxial ground is directly bonded to the car body. There's also a low pass filter between the radio and the amp and another low pass filter after the amp.
 
Last edited:
I did a search before starting this one, nothing came up.
Ah well...apologies.
The site search function doesn't work so well sometimes. I have much better luck using Google to search this site. In this case if you put "WWDX forum rocket box amp" into Google you will find a couple threads on this very subject from 2019.
 
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Clean? As in not dusty? Or did you mean sampled to an analyzer and you saw third order harmonics higher than acceptable? None of these off the shelf amps have output filtering. For fixing/testing/building these type of amps I picked up a copper version of one of these:


There's no moving parts. They need some Electro-Wash on the SO239s and they work.

If the amp sounded like crap, it was overdriven. These rocketbox, and a lot of other brands as well, state a max input power in PeP. Problem is most people don't have a meter that does PeP correctly. A true PeP circuit requires power (voltage). If your meter works on PeP mode without batteries or other power, it's not really an accurate reading.

These HD500 models are a 0x4, straight thru input, your radio is the driver. The LD500 are 2x4. 2 drivers into the finals. With a decent LPF, I like these amps, especially th HD versions.
Clean, as is not distorted. He was driving it with a 3 watt tube base radio, sounded like shit. I don't need a spectrum analyzer to tell me it is crap, I have ears.
 
The site search function doesn't work so well sometimes. I have much better luck using Google to search this site. In this case if you put "WWDX forum rocket box amp" into Google you will find a couple threads on this very subject from 2019.
Google is the way to search this site imo. This string works well:
site:www.worldwidedx.com ***** ****
*= Search criteria eg;
site:www.worldwidedx.com rocket box amp

Works with other sites Google has crawled too, give it a try.
 
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