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inexpensive/cheap cb amps . palomar/cobra vs. rm/kl

  • Thread starter Thread starter BOOTY MONSTER
  • Start date Start date
REAR PIC

Here is a pic of the other side of the board.
 

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People who buy cheap are usually filled with remorse at a later date.
 
The RM3 transistors are not IRF520s relabeled, that much I know. I've got a KL60 here that blew the transistor, I had extra IRF520s so I slapped one in, I only saw half the wattage out of the amp after the swap.

I don't mind the RM Italy amps, good cheap power, but if I had my choice, I'd go with something that has pills in it rather than MOSFET when it comes to amplifiers.

Just my .02
 
cheaply engineered pieces of junk that bleed over on everything electronic and do the CB radio community a disservice by annoying the neighbors, (i wont have one)

While these are made on the cheap they are not "dirty" unless you overdrive them. This is a quote from K6AER, a HAM op:"There is a constant current regulator made from TR4 and TR5 which supplies current to a forward biased diode D11. This holds the bias at about the same junction threshold of the pair of SD1446 transistors which are configured in a push/pull configuration. This should be a fairly clean amplifier if it is not overdriven. Amplifiers produce two types of interference. The first type which most hams understand is harmonics which will increase if overdriven but the harmonic content (out of band signals as a product of harmonic relationships of the driven signal) which can be reduced with low pass filtering."
I use a KL300P that I drive @ 130 watts on SSB with good reports. Are there better? Yes there are but,these work well too if you dont push them.
 
cheaply engineered pieces of junk that bleed over on everything electronic and do the CB radio community a disservice by annoying the neighbors, (i wont have one)

I agree. Considering they are Class C... The ONLY thing a Class C amplifier can be used on is FM. That's why you hear all these people wasting their power as they bleed over 10 channels in each direction.
 
You are right, They do use mosfets. an RM 4 driver and RM3's in the final.
A wild Arse guess is that the RM-3 is a re-badged IRF520 and they use 8 of them.
We will have to rip the lids off one of them and take a photo!

cheers,
Dave

Another Amp to look at | 91DD018

kl503-back-of-board1.jpg


kl503-board1.jpg


kl503-mainboard-and-case-21.jpg


kl503-mainboard-and-case1.jpg


kl5031.jpg
 
I've recently posted here that I have been running a Uniden Grant XL with a KL 203P. I'm getting excellent reports on this combo. Recently talked with KW35 in Monterrey, CA and was given a good report on clean audio, not overdriven, not crunchy, etc. As I reported before, RM Italy told me via email that this amp is class AB biased. I only paid 50 bucks for it on special at H and Y, and it has performed flawlessly at about 120 watts on AM, and who knows on SSB, my RS meter says it does 180, but I'm not so sure. Either way, it's a good combo with my rig, and getting great reports in QSO's.

73,
RT307
 
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And Booty Monster, rather than repost your pics (thanks for putting them up), I'll say why why why do they insist on putting the glass fuses inside the amp???? :headbang Still, looks a little neater than the recent post of the 5 pill amp. :laugh:

And I'm in agreement with the link you posted as well. It would be nice to have a higher input amp.

73,
RT307
 
it does have a variable on it , but being able to switch out the driver would be nice . hopefully the variable is better than what texas star uses . easily accessible fuses/fuse on the end panel would be nice . but it looks like it would be easy enough to bypass the internal ones and install your preferred type of fuse in the power line . i do wish it was AB biased though .................
 

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