KL203 in black - SSB power rating?

Hi All,

I just received an RM KL203, new.

When looking at the sparse info leaflet that comes with it, it specifies that max input is 10W.
Output max is 100W.

All good.  

However, despite mentioning SSB as one of it's operating modes, there is no separate info given on the instructions for SSB.

People say online that input (max) for AM/FM is 10W but input for SSB can be up to 20W.
Different versions of the leaflet that I see online also say so.

Also, the heatsink on my 203 is black. Most others I have seen (bar one new YT video) are blue.

Does anyone know if this is a new or older model, and if so, would the 20W input / 200W output still stand for SSB?

  Doc

Cant answer the colour question cos I've had two of them and one was blue heatsink and the other was red and the only difference was one had a pre-amp  and the other didn't never seen one with a black heatsink though, but  you can put up to 20watt in on SSB but dont go over 10watts on AM/FM or it will blow the outputs on it, but I never had any problems with any of mine when I had them there good little amps.
also not trying to make you sound if your stupid just dont forget to put the switch to SSB  when using SSB and AM/FMwhen using AM/FM  you'll be surprised how many times you'll forget and do it lol.

Thanks Nubster.

You have the original President Lincoln...!

Is that the one with the NASA / Apollo 11 type roger beep

Yes Dr the real President Lincoln not the horrible Lincoln 2 thing ,I'll never get rid of that radio also got a Midland 8001xt,  dont like new radios there too much menu run and computer programs pain in the arse, I'm old school with my radio been around cb tòo long to change lol, your QTH is Epping not that far from me should be a easy contact QSO for us have to listen out for you.on T5.
By the way I saw one of your black colour heatsink 203's on ebay for sale yesterday, they must be a new styling as I've never seen them like that before.

Silly question, but never thought about this before....

The correct order of things would be: transceiver, followed by KL203, followed by Zetagi matcher / power SWR meter.........
Correct?

Thank you all

Yep your correct Dr

The Doctor wrote:

Hi All,

I just received an RM KL203, new.

When looking at the sparse info leaflet that comes with it, it specifies that max input is 10W.
Output max is 100W.

All good.  

However, despite mentioning SSB as one of it's operating modes, there is no separate info given on the instructions for SSB.

People say online that input (max) for AM/FM is 10W but input for SSB can be up to 20W.
Different versions of the leaflet that I see online also say so.

Also, the heatsink on my 203 is black. Most others I have seen (bar one new YT video) are blue.

Does anyone know if this is a new or older model, and if so, would the 20W input / 200W output still stand for SSB?

  Doc

I have the same amp (mine is blue). The maximum inputs are 0.5-10 watts in FM/AM mode and 1-20 watts in SSB mode. I've never seen a black one and there are none on their website. There are a couple of black ones for UHF and "Ham" use though.

https://www.rmitaly.com/product-category/linear-amplifiers/25-30mhz/page/1/

They are all the same. just different batches. 

RM KL203 is without the pre-amp and with 10w in on FM it will give you 100w output but most people put only around 6w into it for around 60w out on FM

On SSB 20w in will give you 200w PEP output. I have had a few of these and never had a problem with them. On SSB id always put the full 20w into it because remember it wont actually be a constant 20w as the power fluctuates with your modulation so its hard to stress the amp and it works perfectly well.

Make sure your PSU has enough amps because if not it wil make your audio terrible. When using amps with radios i suggest you buy a 30a power supply and you can 100% be sure that you radio and amp are getting enough juice.

SWR must be on point too when using amps. if you SWR is high, that amount of reflected power will be amplified by about 10 times and you dont want that because your radio will become a melted heap.

I have a black one too, If I drive with more than 8 watts a/fm you could cook eggs on the heat sink. and ssb I never drive with more than 6 watts...Any more and it starts to buzz and hum, if I drop below 4 watts I get relay clatter, it heats up so much I had to fit a fan. I got so fed up with it I bought a Yaesu,,,,,,,,,,,,,,,, what a difference, propa job, no 1/2 mile of cables hanging out the back no little black boxes all over the place,, just plug in and play, should have bought one years ago

Thank you all for your replies. Extremely helpful as always!

Just bought one of these and mine is black as well. 10w am/fm 20w ssb.

Paul.

Will these work off 600 watt pc psu at 12 volts ? 

Hi Leonard,

It has been done.....

Mower Junkie PC PSU for CB


Think he's using bigger than 600W though. (Your power supply should show the current for each voltage somewhere, I have a feeling you have a 600W in total unit)

I'm all for playing with and repurposing electronic items but I stuck with a purchased unit designed for the job. PC power supplies can be notoriously RF noisy and the ratings are normally absolute maximum not a 'comfortable' rating.

That said, people obviously do it, just I wouldn't personally trust it.


All the best,
Victor

Sgt Bilko wrote:

Just bought one of these and mine is black as well. 10w am/fm 20w ssb.

Paul.

Hi Paul just wonder how you are getting on with the black coloured kl203p ? You had a chance to do any power input / output power checks on it ?
I thought they were just the same amp as the older blue or red coloured versions but notice on Simon the wizard website it states it’s a new spec version.

The " KL RM 203 Black Amp " i got is doing what it says on the box 10w /100w FM and 20w / 200w SSB.

But that was just testing. On my home base @5w my meter is reading 60w ( new zetagi HP 203W ).

When i had the 7900 i ran it @8w which was giving me 85w out. But i only run the amp for DX.

Paul.

Great stuff thanks for that.

Hi ,Sgt Bilko ,,, are you powering the radio and amp on the same power supply ,, Will a 30 amp work with both ?

Hi Leonard. Yes both from my 50a PSU but a 30a will do fine.
Even running the radio at 10w with the amp doing 100w, the PSU will be fine.

Paul.

Hi Paul, Leonard,

Sorry to Jump in but I have to say Paul, Loving your new Avatar - Brilliant !!!

Brought a smile to my face is all I can say .

hi, i have the RM KL 203P in blue, 100 FM 200SSB, i have run this on a 20amp power supply no problem's, at 13.8volt's, i up graded my linear to a RM KL 400,  200 FM and 400SSB, it draws about 35amp's, and some times pushes my voltage to 17 volt's, depending and the strain, here's my new linear pic, 

to give you a comparison check on the size of the 2x linear's and the power supply needed to run the 
RM KL-400 check photo's,

The Doctor wrote:

Silly question, but never thought about this before....

The correct order of things would be:  transceiver, followed by KL203, followed by Zetagi matcher / power SWR meter.........
Correct?

Thank you all

I would like to clarifie. On this question.

The correct order ONLY to test linear output power is 
Transiever followed by kl203 followed by swr matcher power meter. Then antenna.

The correct order to test swr or use the matcher is.
Tranciever followed by swr /matcher power meter followed by kl203 then antenna. 

I hope that helps someone. 
73s 26 GL79.

26GL79 wrote:

The Doctor wrote:

Silly question, but never thought about this before....

The correct order of things would be:  transceiver, followed by KL203, followed by Zetagi matcher / power SWR meter.........
Correct?

Thank you all

I would like to clarifie. On this question.

The correct order ONLY to test linear output power is 
Transiever followed by kl203 followed by swr matcher power meter. Then antenna.

The correct order to test swr or use the matcher is.
Tranciever followed by swr /matcher power meter followed by kl203 then antenna. 

I hope that helps someone. 
73s 26 GL79.

Incorrect. The proper way to test output power is radio, amp, meter then dummy load. Without the dummy load any readings will be inaccurate.

If you're using a matcher then that goes last, before the aerial if it's needed, the load needs to be matched for the burner output else damage may occur.

As for output power, the last thing you want is to over drive the amp to keep distortion and harmonics (nasties) to a minimum, SSB audio will sound bad if it's not truly linear too (most amps aren't). Amps have their uses but don't believe the hype, most ratings are very optimistic, I wouldn't put more than 4/5W in on am/fm or 10/12W in on ssb personally, keeps it safe.

i run mine black kicker at 4w am and fm and ssb 10w only and a fan keeps it cool