looking to add linear

Discussion in 'CB Radio Forum' started by Mud Dog, Nov 14, 2012.

  1. Ridgeline

    Ridgeline Road Train Member

    20,658
    100,386
    Dec 18, 2011
    Michigan
    0
    Wrong, there are other factors, especially with the amp's design.

    RM amps are cheap amps, not much to them and really OK to use.
     
    IndianaF150 Thanks this.
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. Meteorgray

    Meteorgray Heavy Load Member

    754
    596
    Jan 1, 2016
    0
    I did a bunch of reading about these little amps over the weekend. I must say I was very favorably impressed.

    Most of the information I found was very positive about them. I am now convinced they indeed are quite a bargain for the CBer who wants more transmitting range at low cost, and also more hearing ability via the model with preamp (although a preamp in general to many operators is not highly valued due to the fact that preamps also amplify all the background noise in addition to that produced by a target source, so their usefulness is therefore greatly hampered.)

    My impression is that these little amplifiers provide clear and powerful transmissions, reliability, longevity and overall construction quality. That's a lot to say for about 70 bucks!

    I must say, however, that it was pointed out that operator error can kill them quickly. Specifically, if the host radio drives too much wattage power into the amp, and if the antenna / coax system produces SWRs which are too high, then enough heat can be developed in the amp to melt the internals to the point of destruction. It happens.

    But, if the driving power and SWRs is low enough and the amplifiers are thusly kept from getting too hot and the operator overall uses good common sense, most everyone who has tested and used them seem to agree that these little amplifiers are real bargains in the CB world for those who want more communication range.

    I gleaned from my readings that the radios used with the amplifiers should not produce more than about two watts in order to reach the full potential of these amps without overdriving and overheating them.

    Having said all this, it should be recognized that no radio / amplifier is legal to use on CB frequencies that produce above 4 watts nominal power. So you are being a bad boy if you do so.

    IndianaF150, thanks for the tip!
     
  4. IndianaF150

    IndianaF150 Medium Load Member

    424
    405
    Apr 27, 2014
    0
    The Preamp on the RM KL-203P can be turned off by flipping one of the 3 switches on the front. I put 4 watts into mine with no trouble at all.
     
  5. Meteorgray

    Meteorgray Heavy Load Member

    754
    596
    Jan 1, 2016
    0
    Indiana150, well, you made me do it: I took the plunge and got a little RM KL 203P last week. It came to the doorstep for $75 shipped. It's a lot of dynamite in a small package!

    I hooked it up to my little Uniden 520 and its 55-inch Wilson 500 mag mount antenna on the roof of my Mazda sedan, and it does reach out and touch people all right. I haven't tested it for how much extra range it's giving me, but I'm getting a lot more responses than the little Uniden ever got barefoot!

    My SWRs with the Uniden barefoot are in the 1.1 and 1.2 range with the 203P in line but "off." When I turn the power "on," the SWR rises to about 1.5 on Channel 19. I believe it is common for an amp to cause the SWRs to rise a bit due to the magnified power the antenna system has to handle. I believe 1.5 is an acceptable range to be in with an amp.

    One little curiosity is that the (very sparse, very small, and very multi-lingual) instructions specify a frequency range of 10-22 MHz. This would seem to imply it's not good for at lot of HF use, including the popular 10 and 11 meter range. I don't know if they did this for cosmetic purposes in light of 11 meter rules in the US, but it goes against all the testing and experience I've read about that these little units are good from 10 to 30 MHz.

    In any case, I'm really happy with my little amp. I even enjoy the preamp feature with the boosted receive. Although it does magnify unwanted noise too, it is advantageous for reeling in a distant station when the background noise lets it do that without too much of a din.

    I appreciate your bringing up this little bundle of joy to our attention! It's quite a bargain for the boost!
     
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.