Any AM Deadkey Input Difference for the RM Italy KL 503 vs KL 503HD?

[skiman1]

Is there any change in the AM deadkey input limit for the RM Italy KL 503 HD vs the original KL 503?

I know for the non-HD version its 1-2w and low swing and for the HD version they say up to 35w, but no mention if a higher carrier can be used. I believe the only difference in the two is the input mosfet driver has been removed with the HD version.

I have a Kenwood TS-590 that I would like to use with it but the only issue is on the AM side where the lowest carrier setting is 5 watts so if it can't handle a 5w carrier, its moving on time! Thanks!

 

[r carl]

It say's input power - 1 - 35 W on all modes.

 

[Big Kahuna]

Well it's advertised as being able to handle 25-35W (different advertising on different sites). 5 watt deadkey might work but no idea what the amp output would be on the HD version with 5 watts input. If you key 5 watts input and amp hits 200 then not going to give you a very good swing ratio. How much does your Kenwood swing from 5 watts? That might be a bigger issue if you're pushing 40-50 watts swing. You might have to adjust your radio gain to reduce PEP to keep it under 35W.

Your radio alone should do 100w, not sure a KL503 is going to make a huge difference for distance.

 

[skiman1]

It say's input power - 1 - 35 W on all modes.

I'm sure that means more for the PEP than AM Carrier. On the non HD version its 1-6w but you don't dare run over 2w carrier otherwise the sound like crap, 5w and POP goes the mosfet

 

[Big Kahuna]

Rooster CB videos shows a video where he says he's putting 2-3 watts into it - you could watch the video and try to figure out the scale although he doesn't actually show the deadkey so not that helpful.

I believe it's still a 1 x 8 so they simply are limiting the input going into the driver vs the regular 503, basically trying to dummy proof the amp a bit I guess.

 

[skiman1]

Well it's advertised as being able to handle 25-35W (different advertising on different sites). 5 watt deadkey might work but no idea what the amp output would be on the HD version with 5 watts input. If you key 5 watts input and amp hits 200 then not going to give you a very good swing ratio. How much does your Kenwood swing from 5 watts? That might be a bigger issue if you're pushing 40-50 watts swing.

Exactly, it really depends on the how the structured the input and the padding, and sure it probably won't sound good with more than 2w input like the Non-HD one. I'm leaning toward the 35w limit as being you can run a dual final radio like a Lincoln II and have no issue instead of popping the input driver if swinging too hard. From what I understand the HD has no driver and has 8 mosfets, where the non-HD is a 1x8. Still may mean the HD can handle more input deadkey without getting "cranky" like a Texas Star 500V vs 667v.

The Kenwood is not a swinging radio, 5w carrier and swings perhaps 10 to 12w.

 

[Big Kahuna]

I'm sure that means more for the PEP than AM Carrier. On the non HD version its 1-6w but you don't dare run over 2w carrier otherwise the sound like crap, 5w and POP goes the mosfet

I think you're answering your own question here Can the HD version take 5 watts deadkey, maybe, but probably not the best way to run that amp.

 

[skiman1]

Rooster CB videos shows a video where he says he's putting 2-3 watts into it - you could watch the video and try to figure out the scale although he doesn't actually show the deadkey so not that helpful.

I believe it's still a 1 x 8 so they simply are limiting the input going into the driver vs the regular 503, basically trying to dummy proof the amp a bit I guess.

Yeah, I saw that video too, and he mentions 1,2 and then 3 watts into it and you are right about the 1x8 in this, I just found this thread and the consensus is sadly what I suspected.

https://www.cbradiotalk.com/viewtopic.php?f=19&p=404702

"Hey guys, I have been studying this KL503HD, it is driven by a single RM3, it drives 8 RM3 mosfets. The variance in power (6 levels) is controlled by limiting the input to the RM3 driver. At present I'm driving the amp with my Galaxy 2547, with its power turned down to 1.25 watts the amp. develops 7 watts dead key on level 4, on level 6 it makes 25 watts. Below level 4 it makes 3 watts on level 3, 2 watts on level 2 and less than 1 watt on level 1. I hope they do mean dead key for the input wattage, my Galaxy's (all 3) and my Connex all kick up close to 60 watts PEP and I don't want to ventilate my new toy. I have sent a message to Mr. Lee at 88 to see if they have any definitive answers about input limitations, if any of you have any more info. or pointers in the care and feeding of this new pet of mine it would be greatly appreciated."

 

[skiman1]

I think you're answering your own question here Can the HD version take 5 watts deadkey, maybe, but probably not the best way to run that amp.

Partially, yes lol! My question is really was it MEANT to handle higher dead keys "properly" as well as higher PEP, or just higher PEP. Really only PEP for the win

 

[bevis]

I have the older 503 that i just got in a deal and my testing shows that it likes a low RMS dead key. Im hitting it with 1.5 watts RMS / Bird average and getting over 250 Bird PEP out of it. I turned up the DK and it did not make much of a difference on PEP. I personally would not suggest you hit it with anymore than about 3 watts RMS if you want it to live very long. For what it is and what it costs, it seems to work well.

 

[Robert Cook Sr]

Yeah, I saw that video too, and he mentions 1,2 and then 3 watts into it and you are right about the 1x8 in this, I just found this thread and the consensus is sadly what I suspected.

https://www.cbradiotalk.com/viewtopic.php?f=19&p=404702

"Hey guys, I have been studying this KL503HD, it is driven by a single RM3, it drives 8 RM3 mosfets. The variance in power (6 levels) is controlled by limiting the input to the RM3 driver. At present I'm driving the amp with my Galaxy 2547, with its power turned down to 1.25 watts the amp. develops 7 watts dead key on level 4, on level 6 it makes 25 watts. Below level 4 it makes 3 watts on level 3, 2 watts on level 2 and less than 1 watt on level 1. I hope they do mean dead key for the input wattage, my Galaxy's (all 3) and my Connex all kick up close to 60 watts PEP and I don't want to ventilate my new toy. I have sent a message to Mr. Lee at 88 to see if they have any definitive answers about input limitations, if any of you have any more info. or pointers in the care and feeding of this new pet of mine it would be greatly appreciated."

seller 88radio tells me rating is P-P rating of HD version, I just using a 5555n11 put in 25 watt dead key and got 450 watts P-P out of it. I run HD with around 8-9 watts dead key and P-P is around 35 watts ,with KL503HD connected and swith in 3 rd position I get 250-275 watts been using this setting now for a year ,get good reports from others

 

[Mikey1966]

Is there any change in the AM deadkey input limit for the RM Italy KL 503 HD vs the original KL 503?

I know for the non-HD version its 1-2w and low swing and for the HD version they say up to 35w, but no mention if a higher carrier can be used. I believe the only difference in the two is the input mosfet driver has been removed with the HD version.

I have a Kenwood TS-590 that I would like to use with it but the only issue is on the AM side where the lowest carrier setting is 5 watts so if it can't handle a 5w carrier, its moving on time! Thanks!

The HD version still has a driver it. Just has a -7db attenuator installed.

 

[9C1Driver]

A local has one of these. They are pretty much a low drive amp. Sounds good on AM and sounds like crap on SSB. They just don't seem to do well over all, he wishes he would have never bought it.

 

[r carl]

A local has one of these. They are pretty much a low drive amp. Sounds good on AM and sounds like crap on SSB. They just don't seem to do well over all, he wishes he would have never bought it.

What does he wish he would of bought?

 

[Mikey1966]

Rooster CB videos shows a video where he says he's putting 2-3 watts into it - you could watch the video and try to figure out the scale although he doesn't actually show the deadkey so not that helpful.

I believe it's still a 1 x 8 so they simply are limiting the input going into the driver vs the regular 503, basically trying to dummy proof the amp a bit I guess.

It has a -7db attenuator inside to make it handle more dead key. No more than 5 watt carrier & 35 swing. I wouldn’t swing no more than 25 because it doesn’t produce anymore power after 25 pep.