| Author |
Message |
    
Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 59
Registered: 12-2004
| | Posted on Wednesday, December 14, 2005 - 6:57 pm: | 
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I have this amp that I got from copper, the problem is that when I turn it on, sometimes the recieve level will drop off after a minute or so, but it will come back when touch the radio case or amp with my hand, any ideas what could cause this. also, I have the amp and radio, magnum 257(blue face) wired to the battery in the truck with 8 guage and 8 guage boing to one of the seat mount bolts for ground. any help would be great. thanks. |
Wildrat
Intermediate Member
Username: Wildrat
Post Number: 478
Registered: 12-2003
| | Posted on Wednesday, December 14, 2005 - 7:56 pm: |
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Sounds like you need to ground the amp.
put a wire from the amp case to ground, all your equip. should have a case ground, including any meters you may have in line.
WildRat
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Wildrat
Intermediate Member
Username: Wildrat
Post Number: 479
Registered: 12-2003
| | Posted on Wednesday, December 14, 2005 - 7:58 pm: |
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That case ground is a different ground than your negative wire for hookup.
WildRat |
1861
Intermediate Member
Username: 1861
Post Number: 413
Registered: 2-2004
| | Posted on Wednesday, December 14, 2005 - 8:17 pm: |
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I WOULD RUN HOT AND GROUND TO BATTERY . PROBABLY A POOR GROUND |
Chad
Advanced Member
Username: Chad
Post Number: 610
Registered: 11-2004
| | Posted on Wednesday, December 14, 2005 - 9:34 pm: |
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Possibly a faulty relay that runs the preamp circuit or pass thru. Relay contacts can become worn or dirty, the slightest nudge can bring them together.
The amp case is already DC grounded by design.
Chad |
Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 60
Registered: 12-2004
| | Posted on Wednesday, December 14, 2005 - 9:56 pm: |
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thanks guys, I was thinking of re-doing the grounds and also adding a case ground to each, radio and amp, but thanks for the quick response's, that's why I love this sight, good people and plenty of help. |
Wildrat
Intermediate Member
Username: Wildrat
Post Number: 481
Registered: 12-2003
| | Posted on Thursday, December 15, 2005 - 9:19 am: |
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The case grounds will probably take care of your problem. All my stuff is grounded in the Jeep.Ilearned the hard way when the metallic face on the mic bit me, and then the chanell knob got me. I redid my grounds and now I don't get bit.
WildRat |
Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 61
Registered: 12-2004
| | Posted on Thursday, December 15, 2005 - 3:16 pm: |
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yeah, I will do that this weekend hopefully and see what happens, it should clear everything up though, I just wanted to ask before I did it so as not to do any harm, but thanks again for info guys. |
Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 62
Registered: 12-2004
| | Posted on Friday, December 16, 2005 - 10:16 pm: |
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well, I got the case grounds added today to the radio and amp and so far everything seems to working great, thanks guys. |
Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 77
Registered: 12-2004
| | Posted on Tuesday, January 10, 2006 - 9:43 am: |
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Hello again, well I think something may be wrong with the KL-300, everytime I try and use it now everyone tells me that it's cutting out really bad, when I turn it off they say it sounds great, even had my wife try it with listening on a handheld to see, and does cut out really bad, any ideas? |
Chad
Advanced Member
Username: Chad
Post Number: 641
Registered: 11-2004
| | Posted on Tuesday, January 10, 2006 - 12:12 pm: |
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How hard are you driving it? Are you supplying it with enough current (wiring appropriately sized?) Just because the wires coming out are small does not mean that you can run that size to the battery. I have found 8 gauge MINIMUM to be best.
Can you hear the relay’s chattering, or see front panel lamp dimming?
Chad
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Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 78
Registered: 12-2004
| | Posted on Tuesday, January 10, 2006 - 6:49 pm: |
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I have 9 guage going straight to the battery through a fuse holder(20Amp) and 8 guage ground, and yes, I can hear the relays chattering sometimes, I have ran case grounds also, but didn't really help, it really chatters bad on ssb but am it doesn't chatter, but I am told that it is cutting out really bad. the lamp doesn't dim though.
James |
Chad
Advanced Member
Username: Chad
Post Number: 643
Registered: 11-2004
| | Posted on Tuesday, January 10, 2006 - 9:04 pm: |
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It sounds like it's going into under-voltage conditions. How's the power out? If you are hitting 200W at idle I'd be happy, you really gotta give it the juice to get more. I can get around 225-250 clean on SSB PEP with 14.4V going to it.
Also higher SWR will make it draw more current, is this OK too? How long is the 9Ga cable?
Now that I think about it the amp will chatter before the lamp dims. Try an analog DVM right before tha amp power in and let 'er rip. See what the voltage sags to, you may be suprised.
Chad |
Wildrat
Advanced Member
Username: Wildrat
Post Number: 630
Registered: 12-2003
| | Posted on Tuesday, January 10, 2006 - 10:44 pm: |
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9 ga. ? |
Chad
Advanced Member
Username: Chad
Post Number: 645
Registered: 11-2004
| | Posted on Wednesday, January 11, 2006 - 10:11 am: |
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They make 9Ga. |
Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 79
Registered: 12-2004
| | Posted on Wednesday, January 11, 2006 - 12:10 pm: |
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oops, I meant 8 guage |
Mikefromms
Advanced Member
Username: Mikefromms
Post Number: 835
Registered: 6-2003
| | Posted on Wednesday, January 11, 2006 - 12:44 pm: |
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Be sure you are not overdriving it or for that matter underdriving it. I like the amp a lot.
mikefromms |
Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 81
Registered: 12-2004
| | Posted on Wednesday, January 11, 2006 - 3:36 pm: |
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I am using a mag 257, at first I had the RF all the way down, and then I tried turning it up just a little but that did not help any,if I remember right 808 used this same amp on a 257, Icould be wrong though, anyways, I will keep messing with it to see what I can find, I may try another electrical ground and see if maybe that is the problem, but dont think so, who knows.
James
CEF 590
Va Beach |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1148
Registered: 7-2004
| | Posted on Wednesday, January 11, 2006 - 8:35 pm: |
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Assuming your switching the AM/SSB switch
on the amp when changing from AM to SSB.
Check and make sure your radio is only
putting a 2-3 watt deadkey into the Amp.
Anymore and it could be overdriving it.
Make sure your antenna SWRs are set low
as possible.
Make sure all your coax connectors are good
and screwed on tight. Jumpers are good ect.
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Chad
Advanced Member
Username: Chad
Post Number: 646
Registered: 11-2004
| | Posted on Wednesday, January 11, 2006 - 10:29 pm: |
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Same setup here. Leave the SSB switch on all the time, I have never touched mine and unless you are in a riddle contest on AM the delay will not be noticed.
I tuned my 257 as per the tune-up instruction, no more. I DK 40W and swing around 150-160 AM. Most of the time half of that out of preference. On AM the RF out pot is at a quarter or less. SSB is a different story. I watch my peak out on the meter after the amp and tune to that. On SSB it's between half cock to 3/4, I think it's an audio taper pot  SSB it will do around 250 with 14.4-14.7V into it. I keep it around 200 or less, A few have complained about class C but not many! Just don't smash it.
Those suggestions and again, supply is key, they take power in gulps, peak current is high, give it room to breathe.
VERY IMPORTANT---> Leave the amp on low. This just a sensitivity switch and not a power limit. The amp WILL MAKE FULL POWER ON LOW. I cannot run mine on hi with the 257, it just don't work too well, way too touchy, esp for mobile! (mine is base)
Chad |
Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 83
Registered: 12-2004
| | Posted on Thursday, January 12, 2006 - 11:19 am: |
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thanks for the help guys, I have my swr's at around a 1.3:1, before and after the KL, all connections are tight as I check them at least once a week.
Chad- you are saying that you run the Rf on am at 1/4 or less and on ssb at half or 3/4, I was afraid I burn this thing up like that, my 257 was bought from copper and tuned there also. not sure what voltage is going into the amp, dont have a meter but may try and get one this weekend and check. would a poor electrical ground cause this, I know on audio amp's it cause it to come on but when music is played they almost go off from power comsuption, just a thought, I will have to check that this weekend if I get a chance. Thanks again guys for the help
James
CEF590
Va Beach |
Chad
Advanced Member
Username: Chad
Post Number: 647
Registered: 11-2004
| | Posted on Thursday, January 12, 2006 - 9:11 pm: |
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Poor electrical ground will do it. Again power switch on amp should be on "Low" to run those power input levels. Mine never comes off of low. No smoke yet, it runs clean and does not get hot. I'm not a ratchetjaw though And I run mostly SSB with a lower duty cycle. And as for DC ground think of it as an audio amp, it pulls in gulps.
Chad
Chad |
Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 86
Registered: 12-2004
| | Posted on Thursday, January 12, 2006 - 10:12 pm: |
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yeah, I have it hooked to the same spot as my audio amp which runs just fine, but I remember now thinking back that you really should not ground multiple stuff like that at the same place so I guess I will try and move it this weekend and see if that helps out, I really want to get this thing going right, more power, more get out...LOL...maybe. again, thanks for help.
James
CEF 590
Va Beach |
Chad
Advanced Member
Username: Chad
Post Number: 648
Registered: 11-2004
| | Posted on Thursday, January 12, 2006 - 11:04 pm: |
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Woah, in audio you want to ground at the same place, I would keep it there if you are not having RF problems with the audio system, it's not like you are hammering your system while you are talking, unless, well, you are that guy... Nevermind, I trust you
When I had the KL300 in my truck it was mounted with the audio gear behind the seat running from the same power and ground and loving it. 4 Ga Harris Weld-Flex from the battery and grounded to the seat bolt via the same type wire. Had a couple RF problems, most occured from the PWM supply in the audio amp!!!
Amp was a MTX PRO4005 running triamped with no passive crossovers (no chokes in speaker line) still no problems. If you have big audio close try running from that power if it's larger and easy to get to... just for grins. Got that power switch on Low?
Chad |
Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 87
Registered: 12-2004
| | Posted on Friday, January 13, 2006 - 12:16 am: |
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actually all I have is a 340 watt jensen mono block and kicker comp vr 12, but the power wire is also 8 guage, I used that because it's what I had, and I figured that would be plenty for either amp, jensen or KL, but no I actually leave the jensen off because it "messes" with my 257's recieve a little, adds noise. I may get some more 8 guage and try a battery ground for the KL this weekend. as far as that guy goes, I know the type you are talking about...LOL. and I will also try the switch on low, I had it high and low about the same so I'll just leave it on low from now on, thanks for the advice though man, I appreciate your time and help |
Chad
Advanced Member
Username: Chad
Post Number: 651
Registered: 11-2004
| | Posted on Friday, January 13, 2006 - 9:46 am: |
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Aaahhh see, it's the power supply in your jensen like the one in my MTX! The MTX even wiped out my AM radio (broadcast) I didn't get my WLS fix till I solved that one.
Just for grins, do you have any extra power cable or did you cut to length? Try putting a few coils in it and taping it together, just like a 4"loop at a few turns. Same may say I am crazy but I found that to help mine a little. I think the KL300P DOES throw some RF back at the PS. The length of the wire may be such that it is resonating at the transmit freq and causing some back EMF thus choking the amp. You could also try running the car amp hard, turning the mic gain all the way down and throwing a healthy dead key, how does the car amp respond? Does it choke it back, cause it to go into protect?
Chad |
Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 88
Registered: 12-2004
| | Posted on Friday, January 13, 2006 - 10:56 am: |
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never really thought about all that, but will defenitely check into that, hopefully tomorrow, sunday Iam hoping to be able to at least get on the radio period, 2 year anni. and dont what the xyl has planned yet..lol. I have some extra cable inline so I will try the loop thing and see what happens, as far as the jensen, never noticed any kind of problems other than it raises the noise level when it's on.
James
CEF 590
Va Beach |
Navyrebel782003
Member
Username: Navyrebel782003
Post Number: 90
Registered: 12-2004
| | Posted on Saturday, January 14, 2006 - 7:12 pm: |
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Chad, well I tried the loop thing with the power cable and so far it seems to have worked, had a couple of radio checks from locals today all seemed to say that it sounded good, thanks for the help man, lets just hope that this took care of it all, thanks again man.
James
CEF590
Va Beach |
