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TNT 600hd amp making weird noise


To start with here are the specs on the amp.


TNT 600hd

Transistors 4 x 2SC2879
Dimensions H 4 3/4' x L 11' x W 6 3/4'
Amp Draw (maximum) 100
Class B biasing
SSB Delay yes
Pre-amp yes
Driver Required TNT 250 (optional)
Power Output (RMS) 300 Watts
Power Output (PEP) 625 Watts
Driven Power (RMS) 400 Watts
Driven Power (PEP) 1000 Watts
install recommended with 4ga wire
and 125a fuse. Max input carrier of
20w or 300w max carrier from amp.
Max peak input 240w.



Price: $375.99



That said two thoughts right off the bat based on your video. That radio is no where close to proper drive.....and I hope you have a BIG A$$ power supply. That amp will need at least a 75-100 amps. All i here on the video is a slight wine sound. Again are you feeding it right? Maybe some RF is getting into something. You have alot of electronic stuff right by the amp for it to bleed into.
 
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I hear the Fan, and it slows a little bit when you key, and a faint noise but I might not be hearing what you are.
I did not see what power setting you have the meter on , what is the power going into the Amp, and what are you getting out?
What is the size of your power supply?
Also let us know what the SWR is.
That radio is small, but it should work fine with that amp, you will just not see big numbers out of it, and if your supply is small you might be better off not running a big radio right now.
As suggested, try moving things around a bit, make sure all your jumpers are good/tight.
Is anyone hearing it when you talk to someone?

73
Jeff
 
I made a vid showing what i mean

anybody know what this might be?

I just got the amp today

I think I heard an oscillation happening. It isn't that easy to hear in the video. But if you listen carefully, you can hear it.

'RF feedback' might well be the cause. But where that is happening cannot be determined from the video. Make sure your power supply wires aren't crossing over any coax from the radio or amp. I would also be sure that your coax jumper between the radio/amp isn't just a piece of junk. Then there is common-mode current from the antenna and coax that can be bringing stray RF back into the amp/shack. Lots of possibilities.

Think I would wind each of the power wires to the radio and amp with some ferrite/toroid to keep RF entering the system there. Then, I would put a choke coil/'ugly balun' below the antenna feed point. I would also ground all of the equipment together to the safety ground. Perhaps even the mic is bringing in that stray RF? Possible; hard to say. When running a lot of power, you need to 'get all of your ducks in a row' better than you have. RF can/will leak in wherever it can! At least, from what I can tell from the video anyway . . .

Make sure your power supply is big enough for the job too.
What kind of antenna is used?
 
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