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kl 503

apmr0911

Member
May 2, 2011
15
1
13
hi ppl I have a question I have a kl503 on my semi but I fell it is no working fine and I read the manul and it say need to use a cable of 6mm2 and when I was to going to buy the cable on the shop they said me what dont know that and only know about cables AWG and they sold me a 8 AWG and I fell it is no working fine.. is problem whit the cable? the problem what I fell is what the amp dont give alot of power
btw sorry for my bad english =)
 

8 AWG is plenty big for that amplifier. What are you seeing for output power? Also what Power meter are you using to measure your output power? You also need to make sure your SWR is good or this will also decrease output power.
 
I am using a wilson 2k whith a rg214u from antena to amp then of amp to radio is a rg58 whit 90cm of coax and my swr is 1.3 w/o the amp conected and when I check the swr and watt was whit a mfj versa tuner 2 and checked am power and the mas was 180 watts the amp is brand new
 
Seems that the power wires may be too small. That will lower the power output of the amp. If it is going to require as much as 30 amps to drive in full output; then some decent gauge wire will be required to feed it.

Are you driving it with the right amount of RF power to the amp input?
Too much RF power input has been known to cause these amps to fail; be careful not to over-drive the input.
See the specs below:

From H&Y Electronics:
* MODES: AM/FM/SSB/CW
*FREQUENCY RANGE: 20-30mhz
*POWER SUPPLY/voltage: 12-14Vcc
*IN/OUT ENERGY/amperage: 12-30A
*RF INPUT POWER: 1-6W AM/FM - 1-12W SSB/CW
*OUTPUT POWER: 60-250W AM/FM - 120-450W SSB/CW
*SWR:1.1-1.5
* FUSES: 3x10AMP


Since this amp will draw no more than 30 amps under full load, I would have to say that I wouldn't expect more than 250 watts on AM mode and no more than 320 watts on SSB mode when driven with the proper RF input power.

I don't know what kind of devices they use in this amp - 2290's, 1446's, 2879's (doubtful), or MOSFET's (most likely for that price); but I wouldn't over-drive it.
 
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Seems that the power wires may be too small. That will lower the power output of the amp. If it is going to require as much as 30 amps to drive in full output; then some decent gauge wire will be required to feed it.

Are you driving it with the right amount of RF power to the amp input?
Too much RF power input has been known to cause these amps to fail; be careful not to over-drive the input.
See the specs below:

From H&Y Electronics:
* MODES: AM/FM/SSB/CW
*FREQUENCY RANGE: 20-30mhz
*POWER SUPPLY/voltage: 12-14Vcc
*IN/OUT ENERGY/amperage: 12-30A
*RF INPUT POWER: 1-6W AM/FM - 1-12W SSB/CW
*OUTPUT POWER: 60-250W AM/FM - 120-450W SSB/CW
*SWR:1.1-1.5
* FUSES: 3x10AMP

He's using 8 guage wire.

Sent from my phone.
 
He's using 8 guage wire.

Sent from my phone.

Saw that; thanks m42 . . .

First thing I would do, is make sure that none of the power connections from the battery or at the fuses are getting hot or warm. That would indicate resistance to current flow. If so; then corrections would need to be made first.

If all of the connections and connectors are correct; then I would have to say that some of the output devices might have failed. If the output devices are MOSFETs; then that wouldn't surprise me too much either.
 
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I am using a ss 3900hp I ajust te vrs for dont get more than if 6 at am and 12 at ssb but I think is cable because the amp manual say: use supply cables as short as posible no longer than 3 meters, whith a section of at least 6mm2
and is that part what I dont undertand fine because y english sux I dont know if is 6mm2 of the cable or the core of the cable if u can see here it say the cable 8 is 3mm2 the core American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies but if is not the core and is the cable then is ok because is as 6mm2 =)
 
I have this amp too. I bought it a few weeks ago. I don't know if it means anything or not but in my case based on driving it with just under 2watts I get around 240 out of it on AM... On SSB I can't top 300 but that's ok with me as long as there is no problem anywhere. I really don't want more than that anyway. I use 10 gauge wire straight to the battery. I got mine from HY electronics and was expecting the blue one but RM must have Updated their stock because the 503 is now silver and built better. even has mounting slots on the base of the amp now. Hope this helps.
 
I have this amp too. I bought it a few weeks ago. I don't know if it means anything or not but in my case based on driving it with just under 2watts I get around 240 out of it on AM... On SSB I can't top 300 but that's ok with me as long as there is no problem anywhere. I really don't want more than that anyway. I use 10 gauge wire straight to the battery. I got mine from HY electronics and was expecting the blue one but RM must have Updated their stock because the 503 is now silver and built better. even has mounting slots on the base of the amp now. Hope this helps.


So how do you figure it's "built better" ? Did they fire the 8 year olds and now have ten year olds doing all the soldering? Just wondering how you decided it was built better.
 
It has a very clean circuit board for one... But wait I'm not going to write for the next ten minutes trying to explain a good product to someone who is an RM hater. bottom line is it's a very good amp for those who are serious about the 503. They are silver now and yes they are built better from a mounting and wiring standpoint from the old ones. Inside is the same great quality as always.
 

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