| Author |
Message |
    
Swisher
New member
Username: Swisher
Post Number: 5
Registered: 2-2008
| | Posted on Wednesday, December 03, 2008 - 5:32 pm: | 
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My 550 bass amp was working fine using a cobra 2000 and a magnum s-3. 4 watts DK with cobra and 2 watts with s-3. Now I am only getting 1/2 watt with amp on turned over to the #6 position. Sounds like relay is pulling in, but no power coming out. Any suggestion on what is happening. |
Hotwire
Senior Member
Username: Hotwire
Post Number: 2689
Registered: 1-2005
| | Posted on Sunday, December 07, 2008 - 11:49 am: |
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What is the max PEP from the amp with the half watt deadkey??
Kenny
CEF491
Reading the mail around Indianapolis Indiana!
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Swisher
New member
Username: Swisher
Post Number: 6
Registered: 2-2008
| | Posted on Monday, December 08, 2008 - 10:24 am: |
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Hotwire-With Amp on, it will only swing to 2 watts turned all the way up with either radio. SWR is 1.3. Didn't hear no pop or smell anything after I noticed that it was not working?? |
Hotwire
Senior Member
Username: Hotwire
Post Number: 2694
Registered: 1-2005
| | Posted on Monday, December 08, 2008 - 11:49 am: |
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I have never owned a KLV 550, I think it is a 2 transistor model. The range of input for those amps is important. With the Cobra you probably get around a 20 watt swing to drive the amp, 4 watts to key the amp is a tad high but if you keep the amp cool should be OK.
The Magnum S-3 keying the amp at 2 watts is normal for those type of amps. The Magnum S-3 has a much higher PEP (swing) than your Cobra, nearly double. Actually I'm sure the S-3 is capable of 50 watts swing which is more than twice the input swing that the KLV is comfortable with. Especially if you ever used the S-3 modulator with the KLV it was probably torture on the two RF transistors.
Not only do you have to watch deadkey you have to be very careful with how much you swing as well. It is all about the balance of power.
In general, a single final radio matches up to a 2 transitor amp just right. A dual final radio matches up to a 4 transistor amp just right. Sure you can run a single final radio with a 4 tranny amp but when you go and run a dual final radio with a 2 tranny amp you risk getting things to hot and damage is possible.
Without inspecting the amp myself I would guess the pills are shot.
Kenny
CEF491
Reading the mail around Indianapolis Indiana!
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Swisher
New member
Username: Swisher
Post Number: 7
Registered: 2-2008
| | Posted on Wednesday, December 17, 2008 - 9:44 am: |
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Hot wire- Opened up the klv550 and found a light brown with rings on it, about 3/16 round and a 1/2 in. long what ever they are called with coating burned off in left hand front of board. There are 2 there that look the same, one facing east- west and one that is burned facing north -south. I have no idea what they are or what the number would be on them. Could not find schmatics for the klv 550. any advice you might what to give. Thanks SWISHER |
Tech291
Moderator
Username: Tech291
Post Number: 522
Registered: 11-2004
| | Posted on Wednesday, December 17, 2008 - 8:32 pm: |
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Swisher,
click on link for schematic and parts list for your 550: KLV550
r16 along side of board is a 15 ohm,2 watt composition resistor.
Tech291
cef291/cvc6
kc8zpj |
Unit199
Advanced Member
Username: Unit199
Post Number: 636
Registered: 8-2003
| | Posted on Thursday, December 18, 2008 - 2:58 am: |
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I own a KLV550 and they are very sensitive to what your dead-key and swing is. When I received mine, I smoked the keying transistor, and the second time around I smoked it again along with a couple of resistors. When I use it now, I run a 1 watt dead-key and about 8 watts of swing. Now I have no trouble with it at all.
HARVE
UNIT199
CEF0210
CVC#018
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Swisher
New member
Username: Swisher
Post Number: 8
Registered: 2-2008
| | Posted on Thursday, December 18, 2008 - 1:02 pm: |
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Thanks Tech291, lots of info, now where would I find a resistor like that? Unit199, most likely did it with my S-3. What would be a good box to use with a S-3 or S-980. I have access to a TX modulator v-plus,TX-dx-350, TX dx-399v, TX dx-500v and a TX dx-667v. Not looking for the big bang, just something that would work as a base unit with a 60 amp power supply and a Imax 2000 without any problems. THANKS GUYS |
Hotwire
Senior Member
Username: Hotwire
Post Number: 2697
Registered: 1-2005
| | Posted on Friday, December 19, 2008 - 5:41 am: |
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Only advice I can give you is to find replacements for those burnt parts and jump in there with your soldering iron.
Calculate the resistor values you need. Radio Shack should have any resistor if not I have had good luck with RF Parts online.
With your Magnum S-3, 60 amp power supply, the Texas Star DX500v would be the amp to go with. Best to run the radio on its own precision regulated 10 amp power supply. Sharing a power supply is going to reduce the amps for the amplifier and if any voltage starts jumping around will be very very bad for a radio.
Disregard all the other amplifiers you mentioned if using the S-3.
Kenny
CEF491
Reading the mail around Indianapolis Indiana!
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Kirk
Intermediate Member
Username: Kirk
Post Number: 344
Registered: 6-2002
| | Posted on Friday, July 10, 2009 - 2:53 pm: |
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I have the same problem! I was suspecting my switch tho. Anyone know the values in the switch? I guess I need to revisit this. It's been down for over 2 years now. I had replaced the R16 resistor and still had issues. I am not convinced it's the finals. I more suspected the switch because I would get erratic readings, then nothing. Sometimes it would be normal, then slowly fall (in power out) to minimal to no amplification at all. Switching the switch sometimes yielded life back....sometimes it didnt. Any more thoughts? I know this is an older thread at this point.-- |
