1. You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
    Dismiss Notice

President Lincoln MK 1

Discussion in 'CB and Export Equipment and Accessories' started by skip searcher, Apr 17, 2018.

  1. skip searcher

    skip searcher Active Member

    Joined:
    Nov 17, 2006
    Messages:
    249
    Likes Received:
    7
    I’m considering purchasing an Amp to run with this radio, one brand that I was looking at was rocketbox Amps anyone own one of these or had any dealings with this brand I will be using it in a mobile .


     

  2. Onelasttime

    Onelasttime Well-Known Member

    Joined:
    Aug 3, 2011
    Messages:
    858
    Likes Received:
    362
    What the h e double hockey sticks is a MK1 Lincoln? Do you mean a regular President Lincoln from the 1990's with the MRF477 or MRF455 final long before anyone thought about putting MOSFETs into them and releasing them as President Lincoln II, II+, III etc????

    If so you need a lot of amp and preferably a bjt amp not a mosfet amp. It never fails someone will forget to turn the rf power down and bam there goes your amp. It is not much different then people forgetting to flip the suicide switch on RCI N4 products and the like. So if you want an amp buy one that you can not overdrive at full power from your radio.

    Rocketbox AMps is always out of stock so how many people on here do you think have had a chance to use one to give you advice on. Currently, they are out of stock on everything except switches and transistors.
     
  3. skip searcher

    skip searcher Active Member

    Joined:
    Nov 17, 2006
    Messages:
    249
    Likes Received:
    7
    Yes that’s the radio I think in N America they are known as the HR 2510
     
  4. Onelasttime

    Onelasttime Well-Known Member

    Joined:
    Aug 3, 2011
    Messages:
    858
    Likes Received:
    362
    You had the Uniden 2830 first then the HR2510 then the HR2600 and last the President Lincoln. Then you had a Chinese knock off called the Emperor TS5010.

    The HR2600 was an attempt at putting something out for true amateur radio operators. That radio was done in by idiot amateurs there are just as many small minded fools in their ranks as there are in CB radio! Different mentality than CB but just as destructive and hateful and just as ignorant! Funny how money and education is not a guaranty of intelligence, common sense, enlightenment and esprit de corps! In fact, the worst thing that ever happened to amateur radio is amateur radio operators, in general, especially the small-minded elitist bigot types!
     
  5. Onelasttime

    Onelasttime Well-Known Member

    Joined:
    Aug 3, 2011
    Messages:
    858
    Likes Received:
    362
    On the other hand, the Galaxy and Connex turd boxes are still with us!
     
  6. Onelasttime

    Onelasttime Well-Known Member

    Joined:
    Aug 3, 2011
    Messages:
    858
    Likes Received:
    362
    With regard to Rocketbox Amps. I noticed that they say you need to swing up to 40 watts to produce full drive with the fets they are using. That should set off alarm bells because that much drive is not at all needed to drive even 4 Palomar mosfets. That means their is in proper matching and combining going on if that efficiency is that lot low. It should only take about 1/2 that max to drive those fets! Look how RCI drive 8 fets with just 2 finals from the radio! To have efficiency that low makes me concerned about hot spotting on those transistors because of that insane input drive!

    If it is an issue of input padding that needs to go right now! Putting excessive padding in the front end of an amp never does the driving radio or the amp any favors in the long run it just creates multiple failure points in the drive radio and the amp itself. Just like forcing input shunt to ground is no go either. When you pad a an amp excessively as heat and input drive changes it can change the load that the radio see's changing reflect dynamically which can wreak havoc with how the rf section in the radio behaves. Ideally you want a steady 50 ohm load all the way through the system. This can have a very real effect on wave form and on the life of the fets now used in radio's becasue the input voltage on the fets changes with the external load they see. Voltage is fairly fixed for us in our application so it is not like your going to see 100V swing but the constant changes do create heat and stability issues. Linearity is easily lost with fets and durability is also a problem. The more constant the load the better they hold up! As the load changes it is difficult for bias to keep pace! Usually the higher the voltage a fet see's as long as you stay with in it's limit the more stability and linear they become but go past it and it is almost an instant pop! Also most of these fets have the best gain done low and have lost a lot of gain by the time you get to 30Mhz. The lower the operating voltage the more true that is. Who wants to operate a fet in a radio at 30V-50V? You could likely use a boost transformer in an external amp but it would never be practical to do inside the radio!

    Just a few things I have been thinking about lately have not tried them myself yet! So do take the above as just a rant not a fact!
     

Share This Page

  • About Us

    The WorldwideDX Radio Forum was originally established in 2001. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. We are working every day to make sure our community is the best Radio Hobbyist's site.
  • Like us on Facebook

  • Premium VIP Member

    The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Care to buy us a beer? We'd really appreciate it!

    Donate to us!