Copper Talk » Ask The Tech » Amplifiers » Back Swing On KL-200P « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Outkast
New member
Username: Outkast

Post Number: 6
Registered: 9-2005
Posted on Thursday, September 29, 2005 - 12:13 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I have been running my radio and amp combo now for quite some time but never really had a chance to get it on a power meter. Last night I borrowed one from a guy at my work and tested the radio 2 watts swinging 5, with a SWR of aproxamaitely 1.5 to 1 but the problem comes in when I have the amp on, dead key with the amp is about 60 Watts but when I modulate it swings backwards to about 40 Watts! The only problem I have had was a squeal problem when I was accidentally keyed to close to someone. HELP!!! I dont want to burn up a good little amp! The Radio is a 148 GTL, thanks in advance!!
Top of pagePrevious messageNext messageBottom of page Link to this message

1861
Intermediate Member
Username: 1861

Post Number: 343
Registered: 2-2004


Posted on Thursday, September 29, 2005 - 1:59 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

YOUR DK IS TOO HIGH , RADIO SHOULD DK NO MOE THAN 1 WATT , DK FROM AMP SHOULD BE ABOUT 25 WATT . THEN YOU WILL SEE FORWARD SWING
Top of pagePrevious messageNext messageBottom of page Link to this message

Outkast
New member
Username: Outkast

Post Number: 7
Registered: 9-2005
Posted on Friday, September 30, 2005 - 12:59 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hmm, well who wants to buy a KL200P? LOL Is there a VR pot or something I can turn down the DK with? I do not want to do any mods my self as I am not good at soldering but if I can just "turn it down" I will do that.
Top of pagePrevious messageNext messageBottom of page Link to this message

1861
Intermediate Member
Username: 1861

Post Number: 346
Registered: 2-2004


Posted on Friday, September 30, 2005 - 8:45 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

WHAT RADIO ARE YOU USING ? THE KL 200P IS A GOOD LITTLE AMP -- SHOULD DK ABOUT 25 AND SWING 90 TO 100 IF RADIO IS SET RIGHT .
Top of pagePrevious messageNext messageBottom of page Link to this message

Outkast
New member
Username: Outkast

Post Number: 8
Registered: 9-2005
Posted on Friday, September 30, 2005 - 1:13 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

As in the first post I am running a Cobra 148 GTL, if there is just a way to turn down the dead key I will do it but I dont realy have a tech around here I trust inside my radio at all so anything to complicated is out of the question.
Top of pagePrevious messageNext messageBottom of page Link to this message

1861
Intermediate Member
Username: 1861

Post Number: 347
Registered: 2-2004


Posted on Friday, September 30, 2005 - 2:54 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

SORRY , I MISSED THE TYPE RADIO IN FIRST POST , TAKE SPEAKER SIDE CASE OF AND TURN VR 10 ( I BELIEVE THAT,S RIGHT ) YOU WANT ABOUT 1 WATT OUT OF RADIO OR 25 OUT OF AMP -- IT SHOULD TALK REAL GOOD AT THAT HOPE THIS HELPS , LET ME KNOW HOW IT WORKS OUT .
Top of pagePrevious messageNext messageBottom of page Link to this message

Nobodyknows
Intermediate Member
Username: Nobodyknows

Post Number: 107
Registered: 4-2005
Posted on Friday, September 30, 2005 - 7:20 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Before you go turning the VR, I reccomend you use a fine tip marker and mark where the VR is set at. Dont adjust the chrome cans. Also you would probably see backward swing if you read it on a meter that isn't a "Peak" reading meter.
Thru the years all ive had is the cheaper swr/power meters and always got either no swing or backward swing. I bought a DOSY "Peak reading" meter a few months ago (copper elect.) and it shows good forward swing where my cheapies showed backward swing, especially when running an amp.
I only brought this up because you didn't say what kind of meter you're using.
It's pretty simple to adj the DK on the radio yourself, just get it at 1 watt and you're good to go. Everyone says the KL amps want a low DK to last longer and run cooler and thats how i run mine. Thats good advice above my post because mine (kl-60) still works like it did when it was new.
Top of pagePrevious messageNext messageBottom of page Link to this message

Outkast
New member
Username: Outkast

Post Number: 9
Registered: 9-2005
Posted on Friday, September 30, 2005 - 11:56 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Thanks alot Nobody and 1861, by the way it is a cheap meter but I think I will take 1861's advice too and turn down the dead key, hopefully it is only cause of the cheap meter but rather safe then sorry.
Top of pagePrevious messageNext messageBottom of page Link to this message

Outkast
Junior Member
Username: Outkast

Post Number: 12
Registered: 9-2005
Posted on Saturday, October 01, 2005 - 3:33 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

O.K. I turned down the dead key to about 1.25 Watts, now the amp dead keys at about 30 Watts and shows no swing witch is more than likely the cheap meter. I will have to find a Peak meter somewhere to borrow for the day so I can see if it is doing what it is supposed to.

Also does anyone know if that chip in the KL-200P must be taken out to use the amp on 11 Meter, I did because when I ordered the amp a booklet that came with amp, not the amp booklet but the order catalog said to convert the KL-200P remove the chip, but I have not noticed a differance on the meter or anything with it in.
Top of pagePrevious messageNext messageBottom of page Link to this message

Patzerozero
Senior Member
Username: Patzerozero

Post Number: 1570
Registered: 7-2004


Posted on Saturday, October 01, 2005 - 5:19 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

without removing ic2, the amp will not work on 11m.

even a 'cheap' meter will show swing. just because it's NOT a peak meter, doesn't mean it's a cheap meter. 'bird' watts, can be meant as a generic term as well, not neccessarily using a bird meter, but just an RMS reading meter, not peak reading. that is a more accurate measurement of the 'power' your amp is doing.

if you have 'audio', then keying 30 watts is fine. no or very little swing on an RMS meter showing 30 watts key, could be showing 40 watts swing on a peak/PEP meter.
Top of pagePrevious messageNext messageBottom of page Link to this message

Nobodyknows
Intermediate Member
Username: Nobodyknows

Post Number: 110
Registered: 4-2005
Posted on Saturday, October 01, 2005 - 8:41 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Outcast, instead of hunting down another meter you can just get a long distance radio check. Find a base station person out there about 10 - 15 miles from you and ask him if he's seeing forward swing on his recieve meter.

Pat, yeah cheap meters work fine but i like to see my Dosy swing when i modulate. It's a little disheartening to have a $300.+ radio and a meter that isn't swinging it's butt off. lol My lincoln is set at 6 watt DK swingin to 32. Sweet!
Top of pagePrevious messageNext messageBottom of page Link to this message

Patzerozero
Senior Member
Username: Patzerozero

Post Number: 1580
Registered: 7-2004


Posted on Sunday, October 02, 2005 - 9:37 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

yeah, yeah, i know, it makes ME feel better, too
Top of pagePrevious messageNext messageBottom of page Link to this message

Cbodenburg
New member
Username: Cbodenburg

Post Number: 1
Registered: 1-2006
Posted on Thursday, January 26, 2006 - 11:38 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

About two months ago I picked up 2 of the new version Mini-Magnums with a claimed 30-watt output. Actually, they DK just under 4 watts and swing about 20 watts. They both drive KL-200p fine and do about 20 watt DK and 65 watt swing (measured on a Dosy).

The mini-mag and amp are wired in parallel to a cigarette lighter plug and draw just under 8 amps. This setup is great for portability as I move them between different cars with a Little Wil mag mount antenna.

I also drive another KL-200p with a General Longstreet modified with a High/Low switch. The Longstreet puts out a DK of 4 watts low – swings about 15 watts, 8 watts high – swings about 25 watts, and about 25 watts PEP on SSB. The amp puts out about 20 watt DK and swings around 65 watts driven from low position. On occasion, by mistake I have driven the 200p on high position and get about 50 watts DK with a little over 100 watt swing. Either setting on SSB it peaks around 150 watts or so.

After a 15 min conversation, I realized I was driving the 200p on the high setting and it wasn’t even warm to the touch! Although I wouldn’t recommend driving it so hard for any length of time.
Top of pagePrevious messageNext messageBottom of page Link to this message

Road_warrior
Senior Member
Username: Road_warrior

Post Number: 1204
Registered: 7-2004
Posted on Friday, January 27, 2006 - 8:47 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I've been running a 3 watt DK into my
KL 200p for 2 years and it always performs flawless.
Still has plenty of forward swing.
Top of pagePrevious messageNext messageBottom of page Link to this message

Drzuo
New member
Username: Drzuo

Post Number: 4
Registered: 1-2006
Posted on Sunday, January 29, 2006 - 9:57 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

This may help. This is what was told to me about rms or average meters, and seems to check out on the scope. On an rms meter there should be no swing on AM.Since an rms meter averages the swing(high peaks minus low peaks) any output above the carrier should cancel out. The reason an rms meter would show backswing or forward swing would be due to non linearities in the waveform. So if the positive crest of the wave is amplified more than the negative you'd see forward swing and visa versa. This non linearity can be cause by too much drive, not enough drive, too small of a power supply, or if the signal from the radio wasnt linear to begin with. I would imagine amplifier biasing could also play into this.When tinkering and using this method to align the drive of a amplifier I've had excellent results,(cleaner IMD specs).When put back on peak mode (non powered dosy peak reading) it swings about 4 times carrier output, but at a total output less than "advertised", but amplifier ratings could take on a whole new forum. Dont take this as carved in stone, just another perspective....
Top of pagePrevious messageNext messageBottom of page Link to this message

Bushwacker5454
New member
Username: Bushwacker5454

Post Number: 6
Registered: 4-2004
Posted on Friday, February 24, 2006 - 11:27 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

When your carrier is set at about 1/2 of the swing there will be no swing either way--increase the carrier to over half the swing and the amp will swing backwards--- set you carrier under half of what the swing is and the amp will start to swing forward
Alot of guys prefer to run high carrier power (back swing)-- gives you more range with less modulation and audio quality--
It all depends on what you like -- maul or swing-- either way is fine provided your not killing the amp
As long as your not overdriving the amp or driving it too hard your ok with backswing-- you can run it like that-- want more cleaner audio, and more modulation--lower the carrier and drive with more swing--of course you sacrifice output power
It depends how you like to run your system

Add Your Message Here
Post:
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action: