RM KL400 Power Tested CB RADIO LINEAR AMP.

RM KL400 POWER TESTED. (READ DESCRIPTION)
This Amp is one of 3 I am testing for power, these are not legal to use on CB RADIO.
That said people do use them, I highly recommend not putting the maximum amount of stated power into them.
An over driven Amp may not last very long (even if brand new)
My advice is get your CB RADIO / ham radio power checked.
Only then will you know what power you are driving the amp with.
Using an amp like the RM KL400 may cause interference to, other radio users, and people who live near by.
If you are told you are interfering with other people get the problem sorted, or stop using the amp.
Other options may be reducing the power you

[@charlieoscar09]

Steve ....Really enjoyed your AMP videos very well explained and the quality of your video footage was excellent..Thankyou

[@CBRadiouk1]

Hi Charlie I try to explain and show at the same time, I have upped my game a little in the vid dept. I used to struggle with grainy video for a long time (indoors) that's why most of my vids ended up being done while driving. There is one more vid its of the KL203P, its ready to go, in fact I may just show it after I have messaged people back.

[@slippery396]

This brand works very good !! ...Strongly recommend them.

[@stephengunrunnerhanson3550]

A great video Steve I fancy one of these and you can buy these with in built fans there on the outside side and will help cool them

[@makarov138]

I am currently running this amp in my Toyota. Works very well on both AM and SSB. Love the preamp as well!

[@noimnotarobotcanubeleiveit7024]

careful with the preamp, it can overload bringing in out of band harmonics. this can lead to hearing images of stations that are not there when you try to reply. its always worth switching it off to check if the station heard really exists there before tx

[@alanchatfield4271]

Meter is about right on 200 scale, this is spot on for max readings for all your amps

[@michaelvolin9749]

Thank you. Great job.

[@indridcold8433]

What is the recommended input wattage for that amplifier. It seems quite forgiving.

[@robertdixon6536]

Great video! I just purchased the 503p.

[@CBRadiouk1]

Hi Robert a popular amp I hear, how is it performing for you mate.??

[@robertdixon6536]

@@CBRadiouk1 Hi Steve. Just need a bit of warm weather here in Canada as we moved and I still have to install the solorcon 5/8 ground plane. Very cheap manual in fout languages..only one sheet of paper.

[@tinkf250]

Awesome video! May just have to try one out myself. By the way your voice reminds me of billy idol.

[@CBRadiouk1]

That's a new one lol. Go for it

[@codhunter.6818]

Great video steve.

[@paulhawk8277]

I flipped my Klein 500 and put a small muffin fan blowing on the transistors....stays cool,but I use ssb most of the time...

[@CB-RADIO-UK]

Its a powerful amp esp as the meter was reading under. Great sharp video footage.

[@noimnotarobotcanubeleiveit7024]

its a good amp if you have a good psu and a good atu to help filter the output. mine runs from a car battery and putting out 150w from 5w in and handles continuous digi modes unlike the kl203 which blew up running digi mode on pskmail

[@locascioantonino]

I like the linea because I don’t feel those they come all different colors what I could see is they could’ve made the body a little bit different at least put a fan in there put some holes if you can put a fan in there enjoy some of that heat out it may be a little aluminum a little bit thicker inside and outside that could draw some of the heat out but for something for a car or something like that or home Excellent I love the video

[@donnyp3001]

Need to set-up my rm 405 up on my rig when I go up mountain with silver rod to see if I can hit London from Wrexham north Wales I know I can hit Birmingham from top of mountain with 50watts

[@LAFFRS]

I'm in Birmingham mate be interesting to see if we could chat sometime

[@oldasdihrt5993]

Good demo ...thanx

[@LeeKirkman88]

I've had a kl500 years and two b550's i only run 5w am/fm and 15w ssb into them and they have never complained once.

[@CBRadiouk1]

Hi Lee u obviously doing the right things there bud. My last 500 was around 15 years ago, at least. I can't remember how I fried the first one. The second one was my own fault, I was running a mk 1 Jackson. I never even had a power meter let alone checked its output. I also had a power mike on it, and was mobile when it went. P1 p2 and p3 gave no output. But p4 5 and 6 were OK. My mate made me an offer and bought it as it was. Soon after I took the foundation, and upped my game . Thanks for the comment bud.

[@jackson4861]

Steve, my magnum s 9 does about 25 watts on ssb, I know the amp specs say 20 max. As long as I watch the heat you think I’m ok running it?

[@CBRadiouk1]

Hi Jack I wouldn't as it could kill your amp. Try to get your rig checked to find out exactly what its putting out. I would then get the power reduced to keep the amp from being over driven. Most including myself ALWAYS under drive an amp. The amp will last a lot longer that way.

[@125southernnh2]

I won't drive mine with more than a 2 dead key. When they say low-drive, they mean it!

[@maddonpeter]

kl405 cause I got kl405 put away from pass 3 years before I move to my new graf need to get my radio set up I don't know if I going to set my anytone 5555 all set up my yaesu 450

[@CBRadiouk1]

Hi Don the 450 does 100w I would go for that..

[@125southernnh2]

I've got the KL 503. It juices about 275 pep, 120 avg with a 2 watt driver.

[@spankthemonkey3437]

125 Southern NH I got the kl200p blue model and it does a 100watts with a single mrf 455 transistor. Had it since October 2014

[@Dazzwidd]

@@spankthemonkey3437 I got about 20 spare MRF455 transistors in my junk box. I've been thinking about getting an amp that runs 4 of them as I'll always have replacements, not that I blow up amps much

[@Bernard-John]

hi good video,well explained,what is your swr reading,and can you tell me what amp power supply do you recommend,thinking of getting one around 190 euro new for the rm kl 405 with pre amp,let you know how it goes,thanks from rotterdam 19 charlie tango 022,sucsess

[@CBRadiouk1]

Hi Ben SWR Was taken care of because of the dummy load. Power supply minimum 30amp. As with most things it better to have extra should you need it. Thanks for the kind words regarding the video.

[@Bernard-John]

@@CBRadiouk1 thanks good to know,😊

[@kaizersoze2606]

Hammer!!!! Hammer!!!! Smack!!!!!

[@notsoandy]

Q can I fit an amp to an old anytone 5555 or do I have to open the rig up & turn the mod down thanks (Andy CT1551)

[@CBRadiouk1]

First things first. check your output power of your radio (whatever it is) Check the maximum you can put into your Amp. if you decide to use the Amp, do some SWR tests on the hot side of the Amp. Presuming all checks out try it on Air get some Audio reports. Try not being tempted to start twiddling inside the rig, most people end up causing themselves more problems. If you run into problems (and need some help) just ask ok fella.

[@notsoandy]

@@CBRadiouk1 Hi thanks for the help will check power at weekend, & I will probably take you up on the offer for help cheers and 73s Andy.

[@EdzashedFudwinkle]

Hi mate, looking alp over for a 505hd or a 505v, the HD is 1-35w input, some of the 505v are 1-15w. 500,400,300's are 1-10w, some are even 1-6w. So if you come across a 505hd, hit me up, as the 700's and 800's, my psu wouldn't cope, cheers Steve, all the best pal

[@orange70383]

I think alot of the people who complain about these amps probably drive them way too hard or don't use a big enough power supply, I've had great luck with mine and I got in 2004.

[@CBRadiouk1]

Hi Orange could be fella, I had 2 of the kl500s the things were just mind blowing and to be fair I am not one for sparing the horses. Bothe went wrong but I started hearing good things about the lesser kl400. No regrets the 400 is a good amp along the way I like others learned by my mistakes and here we are. I have one more Amp vid and More to be done. (all radio related of course)

[@donsilva4441]

How far down the bands can their amps go that are rated for the 10-12 meters ? Ever tried it on 20 meters?

[@CBRadiouk1]

Hi Don to be honest I am not licenced to do so. Most operators would go for an Amp aimed at the ham radio side of things.

[@donsilva4441]

@@CBRadiouk1 ok. Tyvm

[@deenunya7735]

Enjoyable Vid very Informative Theroetically could a Normal 4 watt Cb put through and if so what Switch setting AM or SSB ? Regards

[@hogawitcha1970]

AM with a straight 40 channel cb has it wouldn't have ssb. so it would be AM

[@CBRadiouk1]

Hi well id your rig had ssb, you wouls use the ssb setting. If the rig was only AM/FM then you would use the AM/FM setting.

[@keithh5053]

Hi again Steve. Another daft question. I have bought a Zetagi TM 999 & an RM 203P Lin Amp 100w AM /FM & 200w on SSB. On to my SS6900N Radio. Now the daft question. What order do I use them Radio , TM999 & RM 203P then to antenna or other way around. I have been told that you can use use the Linear safely up to about 8w on AM/FM & about 6w on SSB. Can you please advise Mate? Cheers Keith

[@CBRadiouk1]

Hi Kieth rig, patch lead, amp, patch lead, tuner.. So that's patch lead from rig to rx/rx on amp. Then patch lead from amps antenna socket, to rig side of tuner. Then antenna goes into the Antenna socket of the tuner. You will find your rig should show nigh on perfect swr, into the amp. It's the high power into the Antenna that you will be tuning while the amp is on. Can I take it your swr is high without an amp.???

[@CBRadiouk1]

Hi Kieth I forgot to comment on the power input of the 203. From memory it's 20w SSB and 10 Am/ fm. Really u only want to be driving it at around 5w. I did a power test video on my 203, you probably seen it.

[@keithh5053]

Hi Steve thanks for replying. Yes my SWR is a bit high at 1. 1.7. I know it's in the safe zone but if I am going to use the linear I really need it to be lower. As you know I am disabled so I can't really do any up and down SWR adjustments easily. So I thought get an ATU and any discrepancies I can sort out from my front room. I am trying get things done without having to rely on others coming to my home and altering the antenna SWR. Plus I am still in lockdown which means I can't have visitors at moment. I hope you can see where I am going, self reliance is better than always asking for help.I am 70 mate and have always tried to do things for myself so it comes hard when you can't do it any more. Anyways mate thanks once again, your a real godsend . 73s Keith

[@keithh5053]

Yes Steve have seen all your videos and damn good they are too mate. keep 'em coming . 73s Keith

[@CBRadiouk1]

@@keithh5053 HI Kieth I fully understand, if u need more help just ask ok fella.

[@randyjones7632]

How do i get one

[@paraguard60]

I´ve got a 12v PC cooler fan on my amplifier (Forced air works wonders with long QSO´s)......

[@donnyp3001]

Does fan run all the time all only go on when you key up

[@LeeKirkman88]

To set the power properly on ssb you need to measure the radio output in peak envelope power (pep) . Otherwise you can over drive the amp.

[@randyjones7632]

I need to buy a linear any where

[@MrRichard57000]

steve can you do a video with the pep setting on ssb?so with your pwr /swr meter not on average(the blue button on the pwr meter) but on peak,and 8-10 watts input?you can also see the difference between the averge and pep setting on the powermeter!!! anyway good video!!!!73

[@CBRadiouk1]

Hi Richard you are not the first to ask. If I get time I may do that, thanks for commenting fella.

[@MrRichard57000]

@@CBRadiouk1 oké thanks for reply Steve.......

[@timmack2415]

But what does that signal look like on a scope or service monitor. I've seen plenty of amps that show high power on a meter, but a good amount of that power is garbage.

[@CBRadiouk1]

Hi Tim what sort of scope are you talking about fella??

[@timmack2415]

@@CBRadiouk1 an oscilloscope or a service monitor. Seeing total power on a meter doesn't necessarily mean much. A good portion of that power may be harmonics, or distortion not on the intended frequency of operation. I've seen meters show, for example, 500 watts, but only half of that power is actually radiated on the intended frequency. Spurs, 'splatter', distortion and wide radiation are useless on your desired frequency, but still show as total power on a meter. I wish I could post pics here on TY. I recently worked on an amplifier that was "splattering" RF radiation over 300 Khz, (or nearly 15 CB channels) and was actually only radiating about 35% of total power shown on a meter on the intended frequency (channel).

[@CBRadiouk1]

@@timmack2415 Hi Tim we call them spectrum analyzers bud. Yes i have seen a few tests done that way. Lets be honest most CB Type of amp are not the cleanest. The video was just a power test with the equipment i have at hand.

[@timmack2415]

@@CBRadiouk1 I totally understand that, I was just trying to be helpful by pointing something out. And yes, service monitor/spectrum analyzer are pretty much synonyms, here in the states anyway. I agree about CB amps. Many of them are made as cheaply as possible and lack adequate filtering. I wish I could post a picture here. I received a CB amp that someone purchase at a truck stop. The signal was 300 Khz wide, to be 40 DB down!! And that was an unmodulated AM signal!!! I believe that someone makes these amps in their basement from knock-off drivers and finals made in China. The amp looked beautiful on a meter, but out of the 300 watts shown on a meter, just over 100 watts were actually within the 10khz of the channel being used. It's crazy that there amp are used and the problem only became worse after the FCC banned the sale of any amps that can be modified to operate on 27 MHz in the US, so CBers don't even buy ham amplifiers anymore. Cheers, my friend!

[@johncameron7807]

How many amps in total does this amplifier use

[@CBRadiouk1]

TBH I haven't fired it up for nearly a year. From memory around 20 AMPS. The supply I had it on was a a 30Amp.

[@johntownley83]

Big price diff. between the 203p & the kl 400 just to get 30 more wat. from the kl400.

[@CBRadiouk1]

Hi John I hear u fella. I have both as you probably realise.

[@matthewcallaway9228]

i would not run 10 watts for long into RM amps for long 5watt to 6 watts max power wise they do the power but they can Over heat EASY & Finals can BLOW ZETAGI AMPs are better MORE heatsink ive had B300P & B150 for years & still going Strong RMs are OK for the power but don,t drive them too hard

[@CBRadiouk1]

Hi Mathew if u look at my other vids, you will see one of my b300s. My first b300 I bought from Truck king when they were based In Watford. I must have had that one for around 10 years. In my day I had 2 of the kl500s. Both blew up. This kl400 is nearly 7 years old. As you rightly said, don't push it to the max. The vid was a power test, that's why I put 10 into it.

[@makarov138]

Just noticed your dummy load brand. I happen to live in Mississippi just about 42 miles north of Starkville. Worked there back in the early 70s! Small world my friend isn't it??

[@albertrollan1561]

How much is the price of this linear amplifier? and where can it be bought?

[@CBRadiouk1]

Hi romeo the kl400 has been replaced by the kl405. The price you will have to Google, I paid 175 uk pounds for the kl400. That was at least 7 years ago.

[@albertrollan1561]

@@CBRadiouk1 Whew! after 7 years, the price may seems to have doubled. I'll take ur advice Steve, try to google the price for today. Many thanks Steve.

[@randyjones7632]

Please send me link how to get a 400 linear

[@CBRadiouk1]

Hi Randy just do a google search for cb radio shops in your area.

[@locascioantonino]

You don’t need to drive it with 2 Watts i’ll stay nice and cool with 4 inch or 5 inch fan and positive and negative gauge replace the one that’s right there take it out one step up ortwo if you say the same or are you taking the cover off Make tiny holes that the heat will come out and you can put a fan in there maybe one or two small ones and run a separate wire or you can put the wire but my drawer too much out of the Amp I got a Texas star 667V I put Toshiba read that dot well it was very easy to put in and I change Inside a linear it’s pushing 850 W I did a little bit of modification on the body stays nice and cool but I can run it all the time I 850 W but as beautiful

[@adolph289]

I want one

[@desbelfastireland9982]

GREAT POST.. THANK YOU STEVE... DES CREAN BELFAST 68CT022

[@CBRadiouk1]

Hi Desmond thanks for the comment fella, I have 3 Amps sitting around so I thaught lets have a look and se what they do.

[@edkemp6287]

theres a hack to reduce a winding on the input transformer to get full power with 5w input

[@1dkf4]

I can't find this item anyway you can send one?

[@CBRadiouk1]

look for the kl505

[@alanchatfield4271]

405 is about the same as the 400

[@paulkazjack]

If only yeasu would make an amplifier.

[@bernielista5663]

fire stick pro model guick disconnect

[@globalmobile017]

Now do a heat test with the 9900 😀

[@CBRadiouk1]

Hi Global oh yes all in the pipe my friend, I am not sure my temp gun goes high enough :o) That said I have power tested it, I may do a video showing the results, and the heat test. My 9900 has been well thrashed, and still works a treat. If and when it goes up in a ball of flames I will not hesitate to get another one. I am spoilt for choice right now as I have the 3900,6900n,cre 8900 etc. watch this space as I have 2 more vids to show (of other amps)

[@globalmobile017]

Steve Stevens yes the 9900 is a neat little radio seems to do OK if you keep the power turned down below 10 o’clock. The 9900 you’re really getting hard to find in the state for a decent price. I bought mine for $200 two months ago now the cheapest I can find is $260 for a stop one and a little over 300 for a modified one. I must say I’ve had a chance to play with one of the modified 9900 after the finals had been changed at the stock filters replaced it it was a really neat radio But I think for a few dollars more you can get a nice used hf rig

[@CBRadiouk1]

Hi Global yes they are fetching good money over here as well, as you say nigh on as much as a used hf set. I must be honest I have been very lucky in the radio department, and have now had two 9900s. The one I use is the first of the two, so I have had it for some time. Lets just say I do not spare the horses, at times during the summer the radio was red hot before I even turned it on. To the point that until I cooled it off a little by turning on the AC it would not receive. From then on it was given NO mercy (at all) One thing that did give me the run around was one of the fuses turned it self into a resistor. Mid qso the rig went dead and would not turn back on , I took it indoors and took the lids off. I tested to se if it was getting power (it was) yet turning it back on only resulted in a sort of click from the speaker. At that point I started using the 6900n, thinking the 9900 had blown I even bought new output transistors for it. Then one day I tested the fuses, one of them had a high resistance, after replacing it, the rig fired right back up. In my book the 9900 is pretty much bullet proof, like many others at first the heat from it gave me some concerns. Now I just turn it on and go, 99.999 of the time I only use it on SSB. If I was to start using it on AM/FM, I would consider a fan or back it off a little (or both)

[@danielt.8573]

I'm kinda partial to the Zetagi brand of AMPS.

[@CBRadiouk1]

Hi Daniel 👋 I like the b300p, but never could afford the bigger 550.

[@danielt.8573]

@@CBRadiouk1 I used to have one of the bigger ones back in the day. I had it connected to two used 12v car batteries with a 24v battery charger turned on precisely because I spent the money and couldn't afford a good 24v power supply. On darker nights you could see the tip of the antenna becoming incandescent. Today I only have the B300 P-S and it's connected to an 80a PC power supply - I was skeptical but it works great despite its top being 70a. The radio I still prefer to use is an old trusty President Lincoln I. Thanks for the reply.

[@CBRadiouk1]

@@danielt.8573 Hi Daniel that's 👍 I sold my 2950 ranger to buy a mk1 Lincoln. The only problem was I could not read the display lol. I could but only with my reading glasses on, everything else was blurry. No good while driving so sold it a week later, great rig but no good for me mobile. I also used to run my zetagi from 2 car batteries, all be it on the smaller b300p.

[@mikedaniels9331]

I made a mistake. Bird meter is the way to go.

[@mikedaniels9331]

Bird Mater is your answer

[@buillynilly1107]

You did the entire video on SSB not AM, check your video the switch is flipped up not down

[@CBRadiouk1]

Hi nilly the am/SSB switch was on SSB, BUT WILL HAVE NO EFFECT ON THE TEST. Oops caps but we'll spotted at least you saw it 😉

[@nightlife7231]

On am you Sud not drive that amp with no more the a dead key of 1 and a half watt a lot of people over drive the amp I don't care what rm tell you

[@CBRadiouk1]

It was a full throttle power test. The Amp is around 8 years old, and still works well. You are talking about AM, on FM there is no swing.

[@hymlog]

RADIO OUTPUT 1.5 ...OUT TO AMP...... DONE!!

[@locascioantonino]

These things are not made the cut up for so long and it should be shut off the more heat the worse it is such a pack of cigarettes and stuff for burn inside when you get a Tonna garbage

[@johntownley83]

I think you are testing this amp on the pre amp. setting because this amp says it can do 400 wat. not 150 wat.

[@CBRadiouk1]

Hi John with amp off and pre amp on, it would not produce anything.

[@PhantomWoIf]

its usual for cb amps to make like only 1/3 of their rated power, so 150watt for a "..400" cb amplifier would be normal.

[@terryshrives8322]

5 watts in is to much for this amp

[@CBRadiouk1]

the amp is coming up to 10 years old, and still working.

[@terryshrives8322]

@@CBRadiouk1 crazy, is that with alot of use.

[@CBRadiouk1]

@@terryshrives8322 a fair bit, but its not run ragged.

[@patrickbaer3742]

Go to hamradioconcepts Eric kj4yxzi great video s bio Nice gentleman who snubs no 1 Americans Elmer +++++

[@nightlife7231]

If you will put your dead key at 1 wat and a half it won't pinch off you will get more swing power plz believe me and you are over driving your amp

[@edwardhannahsamuel730]

It gets a hot as a coal fire