Has an electrical engineer dev HF AMP with new mosfet MRFE6VP61K25h?

Discussion in 'Amateur Radio Amplifiers' started by W7EET, Oct 10, 2011.

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  1. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Good info. Did CCI modify the original designs or do you think they're marginal? I've built a few of the CCI kits and they worked okay, but I had to add filter boards after them. I used a simple Drake TV-1000-LP on one of them since I only used it on 10m when I had it in the trunk and my "rig" was an HTX-100 which was only a 10m rig. I modified the CCI RF COR circuit a lot because it wasn't reliable, but the amp itself was; I still have it!:eek:
  2. W8JI

    W8JI Ham Member QRZ Page

    I'm not sure. As far as I know, they never changed them. They were all done by Helge Granberg back when the USA had Motorola making good parts.
  3. W9GB

    W9GB Ham Member QRZ Page

    The only time that I have seen a modification was for part availability, such as the voltage regulator.

    Helge used the circular metal can version, LM723H; Instead of the DIP version, LM723J.

    That was a common usage in late 1960s and early 1970s. Many Popular Electronics, Electronics Illustrated, and Radio-Electronics magazine authors
    used the metal can versions of ICs in their construction articles. They did look more like the discrete transistors of the 1960s.

    The low pass filtering is mentioned in Helge's Applicaiton Notes -- BUT no specific design was included in the
    Applicaiton Note -- SO in the 1970s many of the illegal CB amplifier builder just built what was shown.

    Some poor soul even used the Motorola trademark (which was on PC board artwork in first Application Notes) on the PC boards they made for illegal CB amplifiers.
    They found him --- and he paid dearly for that mistake.
    Motorola eventually edited the Application Notes to remove their name and trademark from the PC board artwork.

  4. W7EET

    W7EET Ham Member QRZ Page

    When I construct this amp; my plans is to leave the 10 meter design out of this amplifier. I am like everyone else with the fear of some CB'er finding it's way of it's construction amp on their table to use on 11 meters. I would like the FCC move 11 meters to the 4 or 5 meter band with it's 40 channels and give back our 11 meters.
  5. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Nice wish, I can't see how it could happen. VHF (30-300 MHz) is fully allocated, even with many TV stations relocating after the digital transition. I think CB should be moved up to the 13cm band so enthusiasts can start messing with microwave ovens to run more power.;)

    That won't happen, either.:eek:
  6. WB0LSR

    WB0LSR Ham Member QRZ Page

    All legality aside, personally I think that if CB amp builders would include the necessary items to keep their signal clean and avoid overdriving the active elements there wouldn't be much of a problem if they do run power. But they don't.. HOWEVER IMO as more and more information about how to properly build an amplifier is found online and elsewhere, future amp builders might be exposed to it and learn something.. keeping them ignorant is the main reason for crappy splatterboxes in the first place.

    I know, I know, the #######s should just NOT run power.. even better solution right? WRONG. Why? Because it's unrealistic. They are GOING to run power whether we or the gov't want them to or not. Flooding the web and any other resource possible with the CORRECT information is far more beneficial.
  7. W8JI

    W8JI Ham Member QRZ Page

    I always felt CB operators should be allowed to run any amount of power they like with only two restrictions backed by civil penalties:

    1.) All emissions outside the CB channels should be in ambient noise at one mile.

    2.) All RFI problems locally are 100% their responsibility.

    That would solve all problems.

    The real thing that went wrong with the FCC started in 1984. Our leaders started thinking government was the root of all evil, big money was good, and started taking the FCC apart and turning it over to political appointees and lawyers.
  8. K7MH

    K7MH Ham Member QRZ Page

    It started out as a pretty interesting thread.

    Looks like it is done for!!
  9. W7EET

    W7EET Ham Member QRZ Page

    No not really it just got side tracked. I am still looking for Electrical engineers to design a pc board for HR amplifier with the mosfet or the new mosfet that is out on the market.
  10. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Do you have a budget for this or were you hoping someone would just do it for the sake of science?

    If the latter, I'm guessing that may eventually happen, but I don't know by whom. Did you contact Freescale to see if they have an HF test circuit on their roadmap? I'd hope, if the device is worthy of HF operation, they'd undertake this themselves as a marketing development tool.
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