Pumphouse brings you the first ever video on the net of a messenger 2KW in action. Check the video below:
YouTube - mess 2kw video.AVI
YouTube - mess 2kw video.AVI
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Messenger 2KW amplifier in action *VIDEO*
- Thread starter pumphouse
- Start date
You do not see that model amp every day, so it is a cool deal....ya the power supply is not big enough, and even with the battery help it is pulling it down quickly.....I am sure it will rock if you could feed it all the Amps it desires...Thanks For the look at a VERY rare Amp!
73
Jeff
73
Jeff
Cottonmouth has one for sale in mint cond.
2. FS: MESSENGER 2K MOBILE AMPLIFIER (MINT), This is a one of a kind and I never thought I would sell this Amplifier as there were only a few made and no longer being made.
This Amplifier is Class AB-1 16 pill all 2879's with fan kit and full remote. This Amplifier is in like new condition, no scratches or dings, no one has been inside this amp for any reason and still looks like it did the day I recieved it new. ($1200.00).
Pretty damn sweet and clean
2. FS: MESSENGER 2K MOBILE AMPLIFIER (MINT), This is a one of a kind and I never thought I would sell this Amplifier as there were only a few made and no longer being made.
This Amplifier is Class AB-1 16 pill all 2879's with fan kit and full remote. This Amplifier is in like new condition, no scratches or dings, no one has been inside this amp for any reason and still looks like it did the day I recieved it new. ($1200.00).
Pretty damn sweet and clean
I don't believe anyone would dispute the output numbers of this amp at normal voltages and adequate current supply, lord knows I would love to have one.
But me thinks his pep kit in the bird meter is a little skewed and may need calibration because with one battery and a 90 amp switching supply those watts ain't gonna happen.
Thanks for the kind words.
The backup battery (the one connected to the power supply) is a big one and that has a lot to do with the peak watts for a short duration. Bird peak meter fine, calibrated by birdman Tim NM3E. If you take notice in the vid, the first test was done with the amp on power setting #4 (hi gear). The bird meter did the 2000 watts (or maybe a line less) and the voltage dropped down to 13 (first key). As the tests go along, you will see the voltage drop down to 12 quickly. The battery was fully charged for the first key but drains on the keys after. The power supply is a two in one deal. It also charges the battery. Same power supply as a IOTA just different name.
Backup battery info:
Fullriver AGM group 31 DC110-12
AH/20 hour........110
CCA .........1150
Weight ..........76 pounds
The video was done so the buyer could see that the functions worked on the amp. I would never run it to talk radio the way the video shows.
Im asking $1000 for her. 18 NEW matched 2879's.
The build pics, more info about the amp is on the link below:
CB/HAM Messenger 2KW linear amp *VIDEO & PICS* by waterbug
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Also upgraded was the bias scheme (now at class B as amp in stock form would get hot just on idle due to manufactures oversight). Modification of the bias circuitry was done by F.G. Best communications in California.
What did the manufacture over look? was the amp applying bias current when not keyed?
Sounds like another Justin DePois lie.
Here is a previous thread about this same amp you state it has ab-1 biasing and then now you say it was upgraded to (class-B).
http://www.worldwidedx.com/amplifiers/29766-inside-messenger-2kw-2-drving-16-pills-2.html
How is going from class ab-1 to class b an upgrade?
http://www.worldwidedx.com/amplifiers/29766-inside-messenger-2kw-2-drving-16-pills-2.html
How is going from class ab-1 to class b an upgrade?
For me, a bit more watts vs ab-1 (from what i was told by Justin). When i sent the amp to him (in 2005), just plugging in the amp to the power leads would cause it to get hot unkeyed.
Justin said it was a manufactures oversight and fixed the problem and said it had to do with the bias circuit.
Bottom line is when i got the amp back, it did not get hot when amp was unkeyed. and I wasnt able to tell if the amp did more watts. He did fix the problem. I was happy.
Justin was doing good work back in 2005. Then he started rippin people off. So sad. He had talent.
The reason i had to change the pills (all 18) is that I had the volts on my car regulator set to 17 and forgot to turn it down to 14 when i put the messenger 2kw in. The box went poof.
All bad parts were changed out and amp works 100%.
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There was most likely something wrong that caused the amp to go into self oscillation which caused the heating issue, if it had been the biasing the amp would have eventually self destructed anyway.
But class b is not an upgrade and will not produce any more watts over what a class ab1 scheme will provide and if anything you'll get more watts with less drive but will have to provide more current (amps) in class ab1.
Now its coming together....this is what peekaboo said about the messenger 2kw STOCK bias scheme:
I know I am bringing an old thread but this amplifier was built this way by messenger. i have worked on a few of them like this. The bias design needs a little work. If a pill shorts out and send the voltage from the collector to the base it will back feed to the base of every pill in the amplifier, some of them had a 1n4001 from the input xfmr to ground and some did not. This helped in the case of a short from collector to base.
Looking back at my old notes, when Justin got the amp, he said that 2 pills were bad and that was the reason for the heat up. He also said that the bias scheme was incorrect due to manufacture oversight and corrected the problem. (Justin said that the amp will run in class B due to the "upgrade"). The word "upgrade" used here means improvement of the original circuit. So i guess my earlier statement about the bias causing the pills to heat up was partially correct. (i did not include that 2 pills were bad....sorry).
Sorry i did not make that clear in the beginning but due to this thread I had to dig deep in the notes from 2005.
Meanwhile, back at the ranch............the amplifier works great, has an "upgraded" bias scheme from stock, and works 100%.
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More than likely the bias circuit was staying on after unkey and causing the amp to heat up. Class B is not an upgrade from AB. Justin probably did not change the voltage or current to the base of the pills anyway so the bias supply is probably still the same.
It was in fact changed. They were idling really high, and it was brought down quite a bit. 5 years ago I cannot remember the figures for this particular amplifier, but I remember the idling current being ridiculous, and way too high.
So you say they were idling really high, why not just adjust the voltage/current to still be in the AB region? Was it trying to runaway?
- No one is chatting at the moment.
...runna pile-up on 6m SSB