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Rocketbox info thread !!! Made in the USA with a reasonable pricetag !

Would you like to build you own Rocketbox linear from a kit ??


  • Total voters
    55

Eldorado828

8-2-8 in the Lonestar state
Feb 21, 2016
2,379
4,191
273
The Lonestar State
I've still got a bag full of the 2030+ just aging away. Never could get them to work correctly during experiments.

Not the animal of this topic but this thread just brought those to mind.
 

443

W9WDX Amateur Radio Club Member
Sep 25, 2010
258
110
53
Texas
Haha someone got that from me. I am the one who originally put the FDA24N40F in a 4x amp back in like 2010. I only told a few people. Yes they do work. Within 5-10% of the correct power output and they are like $3 each. $1 each if you buy 1000.

I think I may even have some pictures to prove it. Let me look for them. That's been a decade ago though LOL.
 
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CommandoTech

New Member
Nov 1, 2021
15
23
3
59
Ohio, USA
Haha someone got that from me. I am the one who originally put the FDA24N40F in a 4x amp back in like 2010. I only told a few people. Yes they do work. Within 5-10% of the correct power output and they are like $3 each. $1 each if you buy 1000.

I think I may even have some pictures to prove it. Let me look for them. That's been a decade ago though LOL.

I just priced small lots of the FDA24N40Fs at $1.60 in lots of 10. The amp is still working flawlessly. The gentleman who owns the amp wants to add the extra 2 mosfets and make it a straight 6.
 

CommandoTech

New Member
Nov 1, 2021
15
23
3
59
Ohio, USA
As a side note the same gentleman who owns that amp just bought a 2 mosfet kit and is having me build it. I like the well laid out design of the board and the biasing circuit is spot on.
 

kc8mob

Active Member
Sep 26, 2017
89
87
48
39
I completely appreciate the behind the scenes logistics involved in low level production. 10,000 units or less a year.

Even though it appears LDMOS is the real way to go now. There definitely is a market for amplifiers that operate on 12-14vdc without DC to DC converters.

With that said.

Take the latest version HG components. Are they still slightly different the Toshiba parts. Yup. But Toshiba's are gone. Done. Have nothing to do with current production or future component support.

Why not just manufacturer amplifiers with HG rf transistors. The 2879 and 454 parts are reliable, produce power and readily available.

If people were smart, they'd buy a complete matching set of finals with their new amp. What's another 100-120 bucks for a 4 pill amp knowing that if even in 10 years, you're a drunken idiot one night and burn up your LINEAR.. you have what you need or the hard part anyways. Okay so some 10 ohm 'identifier' base resistors and a balance resistor for the input/output combiners...

Well there ya go!

The market needs a vendor who offers a tried and true, efficient and conservatively designed range of products for the average radio user. Most people struggle to supply 100 amps at just 13 volts in their vehicle let alone supply that at home. So basically 2 and 4 pill Class B biased amps using stable bi-polar rf output transistors.

The nice thing about 30mhz capable/roll off rf transistors being used in CB amps is they're not capable of producing meaningful energy at 2nd and 3rd harmonics.

Anyhow. The PP100s were turds, so we're the DEI's and even early HG's.

But HG parts made today work well. For 25-30 bucks a piece in low quantity at that.

Just my .02
 
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TRASHYTRAM

OICU812
Jul 19, 2021
33
16
8
Here is a pic of the Rocketbox HD250 that was assembled at Rocketbox.
20220105_183416.jpg
 
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TRASHYTRAM

OICU812
Jul 19, 2021
33
16
8
So just curious, but what fets is he using in the builds now? With all the ekl palomar fets gone he must be using something else?!
The Palomar ERF9530 is what the Rocketbox website says is used. IDK for sure but Whatever they are they work quite well & have very low amperage draw. The amp pictured above has been through Hell & back for the past year & still works as well as the first time I hooked it up. The Sound Quality is much better than the bipolar two pill mrf455 amp it replaced.
 

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