RM KL203P Power tested, and heat build up.

RMKL203P Power tested. READ DESCRIPTION.
As you will know the little KL203 is not to expensive , yet puts out a fair amount of power.
It is not legal to use on the CB RADIO BAND.
If you get one just be gentle with it, ie do not drive it hard.
In my test 6w was still enough to give you enough power for a bit more range.
It is also a good idea to fit a fan to them, I have known RM AMPS to get that hot components melt out of the board.

[@Wilhuff_T]

Good video, no music, good lighting, the use of a tripod. Great job , sir.

[@aeromech8563]

Another great video Steve might be back up your way in the new year 73's for now 🤘

[@HNXMedia]

Love these little amps, got the 203P and the 203. Can't beat them for the price. Recently ordered one from the UK and it was at my doorstep in the midwest USA within 5 days. Solid video!

[@thekingsilverado8419]

They only work on Side band and most folks R buying them for regular AM CB band like I did only to discover after opening the thing up a few months after I bought it it is only set up for 28-29.7 not 26-27.9.... So back out of the truck it goes... Park it next to the used Heath I bought a few years back it only works on side band as well..

[@1OFGODSOWN]

@@thekingsilverado8419 I was given one Today that looks brand new and I assure you that it works just fine on AM? The gentleman told me he didn’t know if it worked but I for sure does and it works well.

[@charlieoscar09]

Good quality video Steve...There must be hundreds of these now in the UK,very popular and quite a robust Amp.

[@robinbrown7019]

Nice clean and you help a lot of people. Thank you Steve. Mr clean and clear speaker. 👌 Robin from the usa.

[@ClassicJunk88]

I dont have a low drive radio with mine, I put 3.5 dead key into it with the mic gain lowered so it's not too much average. love itworks great.

[@paganphil100]

Great video Steve. Different power meters show different results (some read low, some read high) but this video gives a good idea of what this amp can do. According to my meter I get 50 watts out for 5 watts in and I get 100 watts out for 10 watts in (FM mode) with this amp. I'm using the meter on my mfj-971 portable tuner so I don't know how accurate it is.

[@carldorking8924]

A very good review so I brought one 5 watts in gives me 50 watts out more than happy thanks for a very good review

[@CBRadiouk1]

Hi Carl no problem fella, thanks for letting me know the vid helped.

[@johncrouch8988]

Nice video! Just a reminder to newcomers of the hobby. You need a bigger power supply for bigger amplifiers. And you need to decided what gain you would have running an amp-pros and cons to take into account especially on CB band.

[@CBRadiouk1]

Hi John that s a good point.

[@HearGear]

Is it possible to use both the Preamp and the Poweramp at the same time or do i have to flick the switch for each one depending on if i am listening or sending ? Thanks..

[@stephengunrunnerhanson3550]

Great video Steve yes I use one and I run mine on 7w in and a fan to just gets warm I run 40amp wire from my leisure batt a 200amp hour batt and 40amp wire in to the kicker and worked great I have a little FM but most Am and Ssb a great video

[@CBRadiouk1]

Hi Steve thanks bud, I have a few gadgets to help with my vids now. I no longer use an amp, but had them 3 kickin about , hence the video. in fact the KL 400 goes tomorrow, your leisure battery sounds like a monster. My Battery is 115ah but does the job a real treat. Good to hear from btw.

[@stephengunrunnerhanson3550]

yes its very heavy but charged it when I got it but still well charged

[@alanread6596]

Excellent video very informative. 73's Alan

[@ukk2839]

Your right about the short power lead mate

[@control5835]

I'm getting back into CB. Can you please tell me Steve, what the three switches do? Also do I require a tuner, if so does it go between rig/amp or amp/ant?. Also do I swr to tuner on or rig with antenna.

[@spinnerinthebubbleCT4543]

Hi Steve, how many amps from your power supply was you putting Into the amp?

[@ciaranmcmanus3840]

Nice looking metre

[@-CT-SODBUSTER]

Really cool video and very informative! You UK guys are lucky to have that FM option. We don't have that in the United States, at least not legally. I have one of these amps for my CB setup and mine also is for "testing purposes" wink-wink-nudge-nudge say no more LOL. Cheers from across the pond mate

[@CBRadiouk1]

Hi Classic FM is ok but as you probably know u get no Swing. The main advantage is only the strongest signal gets through. U may of noticed if you are recieving a station on AM, and a weeker stations calls at the same time, you sorta hear it. On FM that tends not to happen, although is the two signals are similar in signal.. You may notice it. Thanks for the comment i do have one more amp to test, i will do that soon i hope. Take care be safe.

[@1OFGODSOWN]

On FM it’s all Carrier so no forward Swing like on AM & SSB for more talking power.

[@rod1cooper]

Great video thanks

[@spr00sem00se]

What freq were you using during your testing ? What was the swr level?

[@davidk1579]

I have a question for you, all manufacturer's sites I looked at say input power is 1. wat up to 10w. Some say 1 to 5 wats. But all video I've seen say 1w to 2 w. So what do you say. Thank you. P. S. Just ordered a amp like yours. I am going to run my power off of a car battery 600 cca. With 10 Ga. Wire.?

[@geo098]

Hi Steve Do you use the Sharman swr 006 to swr in your radios or just use it as a power metre. Would you recommend it as a good swr metre.

[@CBRadiouk1]

Hi Gary it's ok as a SWR meter, over time we get to know our kit. For example comparing readings from other meters, and any internal meters as well. I would buy the meter again if I needed to. Hope this helps.

[@terryshrives8322]

I would only use about 2 watts with this little baby. Works great. Nice video.

[@melanieboyd3704]

I got a uniden pro 510xl. I'm getting one today. How do I turn the watts down on the cb. Got a small swr meter. I think I know how but I'm not sure

[@Westy-1]

Melanie Boyd you take any type of CB radio to the screwdriver experts/fiddlers.

[@Westy-1]

Melanie Boyd also you don't use a SWR meter to check or adjust power output. You use a power meter or SWR meter with power function.

[@terryshrives8322]

@@Westy-1 that's correct

[@terryshrives8322]

@@Westy-1 unless you can do it yourself. But you should know what your doing. I've been doing this for years

[@577buttfan]

Great little amps for the money!! Bump bump!!! 577

[@1OFGODSOWN]

Bump Bump? Fist Bumps? 🤪😜😂

[@577buttfan]

@@1OFGODSOWN click click over and out....

[@livelongandprosper70]

i use the RM KL 405 on my ft 817, i use it mainly for HF 80 thru 10 as its a wideband amp... its actually pretty clean for a "dirty" amp, and its variable.. mine doesn't heat up as i only push it to 50w output ...or so..

[@keithh5053]

Hi again Steve. You mention a fan on one of these. Might seem a daft question but where would you mount it and what sort of fan would you recommend? Cheers Keith

[@CBRadiouk1]

Hi Kieth a fan from a pc . If u use amazon or ebay look them up. It's just a 12v fan, that has a screw hole on each corner. You do not have to use one, a normal house fan blowing on an amp will help as well. I pushed some cork in the cooling fins and screwed into that, it's just to keep the fan in place.

[@keithh5053]

@@CBRadiouk1 Thanks Mate. My rantings are answered as usual. 73s Buddy

[@CBRadiouk1]

Hi Kieth so how u getting on with the set up now. All ok I hope.

[@keithh5053]

Hi Steve. Yes mate getting on ok. my fan arrived yesterday so I will be fitting it later today. I have had some great DX too. Poland, Ireland, Isle of Lewis Scotland, Switzerland, Norway to name but a few. Not bad on a bit of choked wire haha. Many thanks for keeping in touch. It means a lot Buddy. 73's Keith

[@phantomsurvivor6169]

CB radio question here. How many watts is recommended for the clearest audio, 1 or 2 watts? I obviously know little to nothing about CB radios but have a Galaxy DX959 and one of these little amplifiers on hand. I understand these are illegal to use on the CB band. My question is from an educational need in an unlikely SHTF situation. Thanks in advance.

[@CBRadiouk1]

Hi Phantom the Max input on this amp is 10w am/fm. During the test you will notice at one point i drive it to the max. (as its a power test) It was also done on FM, there is no swing on fm. If you are asking about AM, then it depends on what you rig is set up like. In other words if you rig dead keys at 2w , but swings to more than 10 you may have problems. In an emergency /SHTF situation you could try 2 or 3 w, if you could not get yourself heard try more. Remembering at MAX POWER these things get hot and pretty quick. Most Amps get fried because of 2 things, high SWR And or over driving. Investing in a good power meter will help you, that way you will know exactly what power your radio produces.

[@phantomsurvivor6169]

@@CBRadiouk1 Steve, thanks for all you do with these videos. Copy that, I will watch the maximum swing as it can exceed the recommended spec. During these presentations, I realize you run the chance of damaging your equipment in the name of educating the rest of us.

[@CBRadiouk1]

Hi Phantom to be honest running an amp at the max, is not a huge risk. Running it to the max for extended periods is. There are 2 things to avoid with any amp, over driving and high SWR. I run all my amps into a dummy load, that shows the amp a 1 to 1 swr. Its just for testing purposes. Some people are not really paying attention, and are quick to bitch. Speed testing a car on an old race track, is not the same as every day use.

[@waltsmith6515]

Yes 2 or 3 dead key

[@Patrickjdee66]

Hello Steve , I have only just bought that amp , the issue I have is when light is green it completely reduces RF gain to zero, the burner works fine and gives me power just the complete opposite from pre amp side, any ideas Steve ? Thanks mate

[@CBRadiouk1]

Hi Patric i have never experienced that fella. If i did to be honest i would not worry. The preamps on these type of amps are pretty rubbish. Sorry i cant be more help fella. ( let me know if u get it sorted ok)

[@1OFGODSOWN]

The preamp is Bad so it will kill your receive when it’s turned On.Seen it many times.🎙

[@maninthevan53]

I wonder if a 3.5 watts in would be a better way to run this little amp, what is the input for the SSB. Season greetings

[@paganphil100]

danny blackhorse: I have this amp and according to the instructions that came with it the maximum input limits are 10 watts for AM/FM and 20 watts for SSB. I use SSB most of the time and I've never had any problems running it at full power. However, if you use it for FM it will get hot very quickly.

[@bibonorway]

I have 3pc of this and thay give 3w=40w, 4w=60w, 5w=80w, 6w=90w, 7w=100w AM/FW swr 1,2 ch.55(dont have dummy). SSB power input 10-15w swing up to 200w pep. This amplifier is NOT recomanded at AM/FM unleast you drive only 3-4w input, then OK and will last many many year :) Remember that the fuse are 12amp so that meen draw more amps not good. Soldier in 15amp car-fuse its a good ide, and a fan on the top of it. All test at 13.8v

[@Andrew-bl2vo]

Morning Steve, recommendations? for SSB , I/P power / OP power FULL licenced amateur,UK

[@CBRadiouk1]

Hi Andrew it all depends on what radio u are using fella. If for instance you was using the 817, and wanted a little more power thats great. However if you were to be using a 100w HF Radio, i would say use the radio and leave the amp out of line.

[@aol767]

To be sure to get out in an ER or Contact a breaker. W out skip ,, up to 100 watter w close to swr reading in short hops is all that works without burnen up your radio and pissen it up

[@coryboyd7958]

Is it possible to test the output power of the Amp with a multi meter?

[@CBRadiouk1]

Hi Cory no fella you need a power meter of some kind.

[@JAMRADIONYC]

You should only hit this amp with no more than 2 watts dead key. I actually dead key mine at 1 watt and it gives me 10, and I swing up to about 100. This amp works the best that way. AM with swing is king here in the US. Hitting it with more than 2 watts you are going to kill that amp fast.

[@UDX-21]

Good info. 21

[@kimberlychasse6049]

Sorry Steve, my mistake,... thought you were doing so on AM. APOLOGISES

[@CBRadiouk1]

No problem at least u made a comment, more vids to follow including. How this hobby started for me, and my journey so far. My equipment over the years etc, look out for it.

[@KE8ODY-WV-Ares-Ham-Dad-3O4]

Whats a good wattage to run into it

[@CBRadiouk1]

Use as little as you can, to get the power you want from the amp.

[@mm7bvp]

Your the same as me.. Each time your thumb brain thinks " which ones the preamp switch and where's the amp switch"

[@ratanator]

hi steve iv sub you keep up good work from ct 2750 hope to chat on air one day all the best mate .

[@eknaap8800]

Please use proper punctuation. You sound like a pastor's preach...

[@thekingsilverado8419]

can I run thing thru 4ft twin trucker antennas????

[@CBRadiouk1]

Hi yes you can, but keep an eye on the swr, on the hot side of the amp.

[@thekingsilverado8419]

@@CBRadiouk1 I just noticed the KL203 amps they will not work on regular AM CB they only work on Side band. Conveniently the MFG left a space where one could fit up to 3-4 mosfets for the AM band but when ya open the thing up it's blank on the AM side. Side band has 3 mosfets in the one area... I have to say it is potent on side band... So all I can do us use it on side band so back out of the truck it comes park it next to the used Heath a guy sold me that a few years ago and all the Heath does is work on side band too... They have been selling the things on Ebay like hot cakes and now it is surfacing that they will not work on the regular CB band... They are set up 28-29.7mhz... Not 26-27.9

[@CBRadiouk1]

@@thekingsilverado8419 Hi Fella thats the first time i have heard that.

[@thekingsilverado8419]

@@CBRadiouk1 Maybe you can tell me what is up with this thing. When I have red linear light lit there seems to be no signal boost. However I discovered that if have the red amp light on I can turn the main on off switch off and it will not power off unless I put the middle switch back to the preamp position. I have not tried to check the signal now with the main switch BACK in the off position with the linear light still on.. Can ya tell me what the hell I am dealing with???

[@globalmobile017]

How about the 503p?

[@CBRadiouk1]

Hi Global I have never used one fella, so cant really say. I will say this though a small amp on a well set up high gain Antenna, will out perform a big amp on a mobile Antenna in the house. In short it is Antenna system first.....

[@rallypoint1]

Awesome test!! Boo on people giving you crap on running high DK watts. How else are you supposed to see how many watts and how much heat it produces? I am running mine on a 3W DK swinging to 7W. Amp on it keys 40W and swings to 100w or so PEP. It gets a tad warm if you’re a bucket mouth.😂 Thanks again for the full throttle test!!!👍🏼

[@CBRadiouk1]

Hi rally I ignore it fella. A power test is just that, like speed testing a car. No one drives their car full speed 24,7.

[@unclequack5445]

If your putting a 5 watt dead key into the KL203P it's already burned out it is 4 MosFet not solid state.

[@CBRadiouk1]

Amp is fine using fm there is no swing.

[@leolbenwayjr6561]

I've had 4 of them.not a good idea to put over 2 to 3 watts in them . Never had any heat problem.5 or 6 is just to much. I do 2 watts good enough.

[@CBRadiouk1]

Hi Leo I drove this one to the max, as it's a power test. For the money they are ok. Would I I drive it hard and sit ragchewing for hours, of course not. As u say a few w in and all is good.

[@alanread6596]

Ideal little amp for a qrp radio (ft-817). 73's Alan 26CT2661

[@CBRadiouk1]

Hi Alan oh yes ideal for the 817 that is a Radio I just could not raise the money for. I did however have the Icom 703, but it was not reliable so it had to go.

[@bobsokoloff6035]

alan read ll ko

[@1OFGODSOWN]

@@CBRadiouk1 my ICOM 703 PLUS is Amazing and I would not own any Yaesu even for FREE.🎙

[@CBRadiouk1]

@@1OFGODSOWN hi matey the icom 703 was my first ever hf radio.

[@1OFGODSOWN]

@@CBRadiouk1 it’s my portable QRP radio and I Love it.I use a 9Ah Bioenno battery with it and it works Amazingly well for 10 watts. I have worked the world from here in North Florida with it.👍🎙

[@INTHEMIX74]

hmm was waiting for you to ssb test but no

[@CBRadiouk1]

Hi 74 no I thaught I would give the more stable FM test, save all the trying to whistle . Not forgetting how it affects the meter etc. You should get some idea of the Amps power by watching the vid. If not buy one and SSB test it and come back with a video of your own, that would be great.

[@user-hy4jt8sr6y]

Why making a video only testing the amp on AM and not testing it on sideband? 🤔🤔

[@CBRadiouk1]

It was done on FM, it's hard to show accurate readings on Ssb. Things like meter ballistics come into play. And I'm not a very good whistling.

[@M6GOF]

@@CBRadiouk1 : You would simply double what the meter read for SSB. 80w TX out on FM would be 160w SSB.

[@1OFGODSOWN]

@@CBRadiouk1 Whistling is useless since nobody communicates by whistling. If it did 1000 watts when you whisked it would be Useless watts.

[@kimberlychasse6049]

You are WAY over driving that amp! That is why it's getting HOT. No more than a 2 watt DEAD KEY should be put into those amps! 2 watt DK with a 15 to 20 watt "swing" will run it WELL

[@CBRadiouk1]

You do not get swing on fm my friend. I put 10w in on fm, fm does not swing. So tell me something else....

[@CBRadiouk1]

@@M70ACARRY Hi Mark it was a power test my friend, pushing it to the max. (its a power test) 10W AM/FM is the stated max input, the results were there to see. It still works fine, and at that power it will get hot, its a small Amp with 100w out put. I have never used it apart from the test.

[@Ranchhand323]

5 watts is too much for this amp. No more than 4 is suggested.

[@CBRadiouk1]

Hi Howard it was a power test, hence pushing it to the max.. It was also tested on Fm, there is no swing on FM. Have a great Christmas..

[@577buttfan]

With 2 watts DK 15 pep I see 30 watts DK out of the amp and 125 Bird peak. i think he means 10 watts RMS swing or FM power..anymore than 3 watts DK and this amp starts to go into saturation gets real hot,RMS starts swinging back and audio gets crunchy. I have put over 15 RMS into them from a 2 watt carrier dual final radio and ran it all day..you just have to be keen on SWR and run a fan. 577 Bump bump!

[@klv400]

Too many experts......

[@chefluigisuperstar3994]

Amp likes 2 watts in then it won't heat up

[@CBRadiouk1]

IT IS A Power test, so I pushed it. No pain no gain, of course way under driving them keeps them cooler.

[@1OFGODSOWN]

If it’s not getting Hot you are short winded and you don’t talk much.Even with low drive it will get Hot if you talk very much as do all solid state amplifiers.It’s normal and what the heat sinks are for.

[@andyr8625]

Too much dead key,only 3 watts max. Also you keyed down pretty long. Those 2 factors are why it got pretty hot on you...

[@CBRadiouk1]

Hi Andy it was a power test fella, not a this is how to do it test.

[@andyr8625]

@@CBRadiouk1 Burn it up,its your video and amp 😀

[@CBRadiouk1]

@@andyr8625 lol the amp is just fine fella. On fm there is no swing, so 5 w in is just 5w.

[@andyr8625]

@@CBRadiouk1 ok

[@chefluigisuperstar3994]

Got to run them on 1 watt.get with it on video.too much loligagin

[@CBRadiouk1]

Walk on by if u do t like it. It was a power test, to the Max. Read the title. You would not do a speed test a car , with no pedal to the metal.

[@CBRadiouk1]

@@joshandangel1980 Hi Josh it was a power test done on FM (THERE IS NO SWING ON FM) More people over here use fm than AM. If I was doing a speed test on a fast car, I would not drive it at 30 mph. The amp still works fine, as do all my other amps.

[@robertdixon6536]

You are way way overdriven . 2 watts max input.

[@CBRadiouk1]

Hi Robert the video is a power test, of what the Amp is capable of. Max input is 10w AM/FM. To only run 2 W would be like speed testing a car in 2nd gear. For the Record I did state the test was done using FM. There is no swing on FM.

[@robertdixon6536]

If FM then use audio limiters.

[@1OFGODSOWN]

@@robertdixon6536 for what purpose would you do that?😵‍💫😳

[@superppp4217]

In AM mode is orrible

[@CB-RADIO-UK]

Yes the heat does soon build on those amps. Good call on the fan.