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Palomar 400 Elite.. had to do it..

Discussion in 'CB and Export Equipment and Accessories' started by CB590, Sep 1, 2019.

  1. CB590

    CB590 W9WDX Member

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    Sending out today to get once over. Noticed a few things.

    Cold solder joints.. one on center pin off switch to board and input tune pot

    IMG_20190905_100541019.jpg

    And this looks not soldered..

    IMG_20190905_095944601.jpg



    And this key circuit is urking me..

    IMG_20190905_100219690.jpg
     

  2. CB590

    CB590 W9WDX Member

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    So shop worked on it. Took whole pcb out of it to check under it to for anything amiss.

    Redid the keying circuit mess and added SSB delay, put my heavy wire inside and deleted the wirenut thing..

    And said "I am leaving the bias
    resistor unhooked, as over-all operation seems to be smoother without it. The AB1 bias circuitry is not good on this unit anyway, as the bias voltage is basically just shunted to ground and doesn't truly bias the
    transistors as needed for AB1."

    Will follow up with pics when I get it back tommorow (hopefully).

    Be nice to see how it works now..

    Also found out my one jumper was giving me higher SWR than my others so I ditched that. Back to 1.2:1 at full stock power on the AT6666. The bad wire was showing 1.5-1 and showed floating ohms when twisting just a hair near the connections with my meter..
     
    999 and Shadetree Mechanic like this.
  3. CB590

    CB590 W9WDX Member

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    Deadkeys on AM 30, 65, 105w. With AT-6666 at about 9am position on it's power knob..

    No chatter anymore either.

    Running on medium I'm seeing with my voice 140-300w on SSB. Happy with that..

    High was like 180-300+ easily. (Meter only goes to 300w).

    SWR from radio to amp is now a comfy feeling 1.3:1..

    Keying looks cleaner, he mounted the transistor to rear panel and he replaced the resistors too and added a cap.

    IMG_20190912_101052173.jpg

    IMG_20190912_101040796.jpg
     
    Shadetree Mechanic likes this.
  4. w9cll

    w9cll W9WDX Amateur Radio Club Member

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    A lot of effort for a 1/2 S unit upgrade over the stock 6666 but if it make you happy that is all that matters.
     
  5. CB590

    CB590 W9WDX Member

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    True but since I sold my TS350 like 4 months back kinda missing the option for sandpiles.. 300-400w PEP is better than 50w PEP..
     
  6. w9cll

    w9cll W9WDX Amateur Radio Club Member

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    True
     
  7. Shadetree Mechanic

    Shadetree Mechanic 808 On The North Side of Dover

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    One half S unit can make a big difference if that's what it takes to get your signal out of the mud. Nice amp, should last you a long time.
     
    CB590 likes this.
  8. AudioShockwav

    AudioShockwav Extraterrestrial Admin
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    He left the bias unhooked because it was causing stability problems with the amp.
    When you add bias to the transistors the gain actually goes up.
    All the parts are there for a crude bias set up, but the builder grounded it out because it is not stable the way it is.
    This was the case on almost all of the vertical transformer 4 transistor clone amps.
    There are no negative feedback loops across the input/output transformers.
    All the palamor 400/boomer 400/ elite 400 and black face 400 clones (Vern built) were all made this way.
    They are not bad amps, just the builder took short cuts when assembling them to save $$ .
    And sd1446 transistors are pretty tough if not abused.

    73
    Jeff
     
  9. w9cll

    w9cll W9WDX Amateur Radio Club Member

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    True but antenna gain can do that as well.
     
  10. AudioShockwav

    AudioShockwav Extraterrestrial Admin
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    So very true.

    73
    Jeff
     
  11. CB590

    CB590 W9WDX Member

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    A99.. no gain.. lol

    Maybe the 104C in the future years when I get to NC, that will have some gain.. :)
     
    AudioShockwav likes this.
  12. BJ radionut

    BJ radionut Supporting Member and 6m addict

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    http://www.radiomanual.info/schemi/ACC_antenna/Solarcon_A-99_review.pdf

    "So what is the TRUE gain of the Antron 99? Assuming a 1/2 wave shunt fed dipole in free space, minus the losses associated with the series capacitance and inductance, according to my math, the Antron 99 has 1.8 dBi gain. That is to say, the Antron 99 has 1.8 dB gain on the horizon over an isotropic radiator. Referenced to a center-fed 1/2 wave dipole, which is the industry standard, the Antron 99 has a NEGATIVE gain of 0.3 dB.
    This could also be stated as -0.3 dBd."
     
    Shadetree Mechanic likes this.
  13. w9cll

    w9cll W9WDX Amateur Radio Club Member

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    so instead of getting a better antenna you would rather throw more RF into a poor antenna expecting better results?
     
  14. CB590

    CB590 W9WDX Member

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    Not really. However, this is not my house and A99 came with me from PA and is up and installed. I don't have options to keep messing with my sister roof and siding with brackets and such. Even a Sirio or other vertical isn't going to give me anymore. Hard to put a M103/104 up on a 1 1/4" post, held onto the wall with 4" standoffs Jimmy rigged with 8" extensions to get under the 12" eves.
     
  15. CB590

    CB590 W9WDX Member

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    Granted there is concrete on the base and there is 2' of pipe in that.. but using 4 sets like this and then 'jimmy rig' with hurricane brackets.. still not enough for the beam wiggle or support.. A99 is 40' to the tip..

    IMG_20190914_132916366~2.jpg
     
    S&W357 likes this.

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