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The place to talk about specific radios, equipment and accessories. Do you prefer the latest generation of rigs and antennas or do you like the classics? Discuss it here!
Just purchased a KL203P.Issue is this.Dead key of 1 watt,I get 35 watts (approx) AM but the amp gets very warm quickly and the S.W.R goes out of the roof!Not a good thing!Setup is this;148GTL-DX to Dosy FC50 counter to KL203P to Zetagi TM999 and onto a Sigma Venom 5/8.Using RG8 mini throughout and no connection issues anywhere.Surely for an amp rated at (exaggerated obviously claims) 100 watts AM and 200 watts sideband,this is pretty crap.
Find it very difficult to get the S.W.R down to an acceptable level using the TM999 as well.Advance power input over 1.5 watts dead key and the S.W.R is manic.Could I be right in thinking the TM999 cannot handle the extra power going through?I know that the setup without it is running 1.25-1 with 10 watts AM and roughly 25 watts pep sideband.
Having read up on others users issues,they recommend an input of only 1-1.5 watts on a dead key.Surely though,the whole point of having this amp is to get at least 50-60 watts on A.M and maybe 100 watts on sideband?
Any ideas?
High SWR with those amps is a well known problem, Apparently caused by harmonics reaching the aerial. They recommend that the patch lead between the amp and transceiver should be 90cm. And an external filter be fitted on the amp output, Didn't help in my case. As for the amp heating up you could fit a small fan on top, About a quid on ebay. And i would ditch the zetagi, SWR shouldn't increase with power unless theres a problem, ie harmonics as mentioned above
Mudslinger wrote:Never had any issues with mine. I have a patch lead of 30cm which is made of RG-213.
Getting hot is normal, I fitted a fan to mine.
Main issue is the s.w.r increases when dead keying you can even watch the meter climbing up!Amp is very close to the rig but cant see that would affect it.HELP
I reckon the problem could lie with your antenna. Maybe the coil inside is heating up.
The modern silver rod type antennas (with the exception of the Sirio ones) are very poor quality, the metal is thin, they are badly made and sometimes the soldering in the base leaves a lot to be desired.
You may also have an iffy connection somewhere or even water in your coax.
If you stick in 1w dead key into the amp then 35w out is very good. If I put 4w FM into mine I get around 75W out. With 7 watts in it is pretty much a true 100W
The SSB output seems to may out at around 150-160w PEP according to my meter.
Mudslinger - Simon
26TM274
26CT612
There is no such thing as a Fidelity 1000 which is too good to scrap.
I posted a similar thread a while back, And someone mentioned that it could be the antenna heating up, Then someone else pointed out that it would take a kilowatt or more for heat to be generated, Plus my dipole is made of thick copper wire, I'd say its down to poor filtering and harmonics being radiated. Seems to be a common issue with that amp and similar cheap amps.
1W in for 35W out is, as mentioned, a bit odd. It's too high an output for 1W in. These amps tend to be fairly linear, in so much as they multiply the input by about 8, so 1W in = ~8W out and 10W in = ~80W out. I have the very similar (same power, different circuit) KL200. and mine behaves fine and follows the X8 rule.Oh, and I tested, on my set-up, patch lead length made zero difference.
May I ask what power source you are using for your set-up?
John, on the S. Cheshire / N. Shropshire border. 26TM953 / muppet handle "Grey ghost" Don't just monitor, key up and talk, otherwise everyone thinks no one else is out there !!!
I think they are great little amps for the money. I have had mine 5 years now and it has been used and abused and is still going strong with no issues.
It even sounds good on SSB, which is good for an amp of this price.
Mudslinger - Simon
26TM274
26CT612
There is no such thing as a Fidelity 1000 which is too good to scrap.
Although mine is the KL200 version, I too am very happy with its performance.
John, on the S. Cheshire / N. Shropshire border. 26TM953 / muppet handle "Grey ghost" Don't just monitor, key up and talk, otherwise everyone thinks no one else is out there !!!
ghost123uk wrote:1W in for 35W out is, as mentioned, a bit odd. It's too high an output for 1W in. These amps tend to be fairly linear, in so much as they multiply the input by about 8, so 1W in = ~8W out and 10W in = ~80W out. I have the very similar (same power, different circuit) KL200. and mine behaves fine and follows the X8 rule.Oh, and I tested, on my set-up, patch lead length made zero difference.
May I ask what power source you are using for your set-up?
Have got a 10 amp constant 12 amp surge regulated power supply so more than enough for the amps requirements.
I should add that the 'feedback' that I was getting at one point was making my 148 GTL DX VERY unhappy,which is when I pulled the plug
I found that my 203p pulls nearly 16A at full tilt.
I know that the instructions say 10A but that is codswallop. I have an ammeter on the power supply and I have double checked it by going through my Fluke meter.
Maybe the lack of adequate current to drive the amp is a source of the issues, and if you are running the radio from the same PSU you can add another 4-5A to the current drawn by the amp.
I have a 25A psu running mine.
Last edited by Mudslinger on 20 Jan 2017, 21:22, edited 1 time in total.
Mudslinger - Simon
26TM274
26CT612
There is no such thing as a Fidelity 1000 which is too good to scrap.
