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Carlbuilt 400HD vs C400 vs CM400

TimmyTheTorch

Well-Known Member
Dec 11, 2022
336
275
73
Northeast Wisconsin
I have a bone stock Radioddity QT60 Pro I currently use as a base, along with a Carlbuit 200HDC (2 years old, driven by <= 35 watts PEP), Powermax PM4-120 amp power supply and a horizontally mounted Maco M104C antenna and V5/8 above it with the ground plane radials removed. This setup works great, at least until squirrels have at the coax again.

I have an Anytone Q5 NII I am setting up and am looking at getting another Carlbuilt amp, this time a 400 series. It'll still be mainly used for SSB and probably have the upgraded C transistors. I can't decide between a 400HD, a C400 or CM400, but am leaning towards the C400 or CM400 but I don't know why I would choose one over the other. The latter two look the same to me except one uses a 2290 as the driver and the other uses a 2879. I don't know how important this is. Variable power would be nice, but is not critical at all. I can (under)drive the 400HD with the Anytone turned up to 11 (Spinal Tap scale, equals about 50 watts PEP I think), or turn it down and use the C400 or CM400.

It's important to me that the signal sounds very clean and does not splatter all over the place. Will audio coming from a C400 or CM400 that are both 1x4 sound as clean as the 400HD just being driven by the radio? It's probably a dumb question, but it's in line with my knowledge of transistors. :)

Do you think the 400HD or C400 or CM400 is the way to go for this?

Here are the base amp specs from the Carlbuilt site:

1785685457696.png


My current ride. If the 400 ends up working out, I will probably downsize and sell the 200HDC.

1785685503654.png
 
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None of those are the way to go. As the other posters have noted they are all unfiltered class C amps and will sound awful, especially on SSB, as well as being splatterboxes.
You want class A/B bias so it sounds nice and clean, and you want a filter so you're not radiating crap all up and down the band. Even RM Italy has amps that do that, so not sure why you would spend a small fortune on a Carl Built splatterbox!
 
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Actually Carl does build biased amps, you just have to check the box for it at the time of purchase.
And I do agree
You should run bias for SSB if you want to keep it clean..
With those radios I don't think you need a driver transistor, but I never liked amps with built in drivers anyway

73
Jeff
 

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