| Author |
Message |
    
Bigbob
| | Posted on Thursday, May 16, 2002 - 8:58 am: | 
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I just ordered a klv550 for ssb and found out it wont work right on ssb. Can you rebias it with out to much power loss?? |
Tech181
| | Posted on Thursday, May 16, 2002 - 3:20 pm: |
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Bigbob,
Leaving this up to Tech671.
Steve
Tech181
Tech181@copperelectronics.com |
Ss8541
| | Posted on Thursday, May 16, 2002 - 10:45 pm: |
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bigbob,
i haven't seen the 550 but i thought it was biased class ab for ssb. how did you find out it wasn't? |
Bigbob
| | Posted on Friday, May 17, 2002 - 6:19 am: |
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I couldn't remember tech671s number,steve I meant no disrespect.Ss8541 check the post below mine {KLV 550 question}! |
307
| | Posted on Friday, May 17, 2002 - 7:15 am: |
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What exactly is not working?
307 |
Ss8541
| | Posted on Friday, May 17, 2002 - 6:13 pm: |
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okay bigbob, i missed that one. if you know how to manually trip the relay (without keying into it), you can measure the voltage at the base of the finals. if it is between .6-.7v it is ab, and will be fine. if not you can use a 50-100ohm 5w resistor and 1n400x diode to make it ab. 671 can go into more detail, or i can pick it up from here if he wishes. i just don't want it to look like i am 'tech blocking' any other techs here. there are many knowledgeable techs here, and when you get several together, there are sometimes 'butting of heads' like territorial rams. |
Tech671
| | Posted on Friday, May 17, 2002 - 11:36 pm: |
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Not stepping on my toes...by all means follow what 8541 directed. |
Bigbob
| | Posted on Saturday, May 18, 2002 - 7:54 am: |
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Placement of resistor and diode?thank you. Robert |
Ss8541
| | Posted on Saturday, May 18, 2002 - 11:18 pm: |
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ok bigbob, i reread the post you directed me to. it says something about class b(which still isn't for ssb push-pull amps since it can cause crossover distortion). if it is class b or very close, that means that there is already some type of biasing present. the problem with class b, is that it is either exactly class b or it is class c or class ab. there really isn't much lead way. anyway, you would need to rework the biasing circuit there to make it class ab. i do this with the stinger boards. they have biasing, but why i don't know since they are still class c amps. might as well have 0 biasing (no biasing circuit).
you 1st need to make sure the amp isn't class ab already or even that it has no biasing. all i have on that amp is the conversion info. with it is an unreadable parts layout. it looks like the 'keying' relay is at the back of the amp. in front of the relay is what appears to be the 'voltage spike' diode. with amp on gnd the unbanded end of the diode. this will close the relay. now measure the voltage on the base of the finals. this is the part of the final closest to the input(small) transformer.
let me know what kind of readings you get and we'll go from there. if there is a biasing circuit already there, we can 1) rework it, or 2) disable it and add the diode/resistor biasing circuit. and of course if there is no biasing circuit, we'll move straight on to #2.
as a last note, are you capable of scanning? if so, a schem should come with the amp. if you could scan it and send it to my email that would help more. if not, if you are fax capable, we can work with that also. |
Bigbob
| | Posted on Sunday, May 19, 2002 - 5:06 pm: |
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I can e-fax with my hp xp scanner but i've yet to rec. my amp,should get it by monday or tuesday,then will know. |
Bigbob
| | Posted on Wednesday, May 22, 2002 - 8:19 pm: |
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I'll be driving it with a 142gtl peaked up but not clipped,was clipped a few years back and it sounded gross,puke,barf,yuck,so had it put back to normal. |
Bigbob
| | Posted on Friday, May 31, 2002 - 10:37 pm: |
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Ss8541 and Tech671 the klv550 arrived has good linearity,no static on transmit,but the pills are not mrf422s(150) but sd1407s(100)watts respectively.The sd1407s are perfect for unpeaked radios they can only take 2.5 watts drive per.Apparently I got a new model or somthing;please tell me the meter is wrong or something,200 watts AM,350 watts SSB.Stalker F9dx 3watts am swings to 12,ssb 19 watts.(radio I did the testing with). |
Ss8541
| | Posted on Saturday, June 01, 2002 - 12:00 am: |
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i meant to tell you i 'acquired' a schem on that amp and see that it has transitstor regulated biasing, that by the schem appears to give atleast .6v biasing. this would put it in class ab. |
Bigbob
| | Posted on Sunday, June 02, 2002 - 12:30 am: |
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I retested the unit it puts out over 300 on AM and over 400 on ssb so I'm satisfied. |
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