Back on track with the EB63A

That’s EB63 alpha.

If you order the parts to build an EB63 140W amp from CCI, you’ll actually receive the parts to build an EB63A. No mention of the A version is on their website. The bulletin available as your guide is for the original EB63.

In short, they offer docs for the old version and sell you the new one. A “WTH?” phone call and follow-up email to CCI got me the new documentation entitled “Construction Hints For The EB63A” which you can download from here. But check out the old version too, for comparison – here it is.

If I can find the time, I ought to have this pup whipped together in the next week or so – I’ve got to procure a heatsink first. Then hook it up to the spectrum analyzer for some jpegs of its (and my filter’s) purity. And speaking of filters, my package from W8DIZ with T50-2 and T68-2 torroids arrived in the mail today.

Now to find an appropriate heatsink/housing…..

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  5 comments for “Back on track with the EB63A

  1. AD6KA
    December 6, 2010 at 10:04 pm

    Hi John:
    Thanks for this info. Lots of changes from the old version, that’s for sure. Yes, CCI needs to update their website badly. They list a completely different large open frame relay for $13.95 as part of the kit, not the enclosed PC mount Omron.

  2. December 6, 2010 at 10:20 pm

    And D2 is omitted; instead, the emitter & base of a transistor are used as a diode to develop bias. Also, many (most) resistor and electrolytic cap values have changed.

  3. AD6KA
    December 7, 2010 at 5:32 pm

    “D2 omitted; instead, the emitter & base of a transistor
    are used as diode to develop bias”.
    My 15 year old EB63’s use this also. It’s actually easier than
    using that oddly shaped (unavailable) diode,as you don’t have to mill the heat sink to accomodate it. Just place it between
    the bottom of the PC board and the heat sink as directed.

    I think it’s crummy that CCI lists, and charges you for, a $14 open frame relay, yet ships you a $3.00 Omron relay. Who knows, it may not matter at all, and does make hookup easier.
    The PC boards traces look much thinner than the ones on my boards. Is the board they sent you use 2 Mil CU (Heavy copper)?
    Can’t tell from the photos. Also, the RF IN & OUT pads are much smaller, with thin traces.

    OTOH: CCI claims that have improved the COR circuit, which looks easy to change to a very low current PTT-to-Ground type.

    I also noted that the EB63A lists a spot in the COR circuit schematic for a “SSB Delay” hookup. Gee, wonder what crowd THAT feature is designed for?
    GL es have fun, can’t wait to see how the “A” unit plays.
    73, Ken AD6KA

  4. December 7, 2010 at 6:40 pm

    Ken, I can’t get over the fact that the documentation on their website is for a version that they haven’t sold in over 15 years! They freely emailed me the info though – maybe they’re worried about making the schematic public as some folks might choose to buy the parts from other sources…

    It is a very simple kit and I am halfway through it as I write this. Took 20 minutes to drill the heatsink, another 30 to stuff all the components except the caps and dual output transistors.

    I’m not sure what 2 Mil heavy copper is but I don’t think this board would qualify for any description with the words heavy or copper!

    I’ll probably have this thing ready to test on 40m by Thursday. If all goes well, I’ll build filters for the other bands & if I still like the amp, I’ll take the plungs and start building CCI’s 600-watt amp. The biggest challenge of that will be building the power supply (50V, 20A).

  5. AD6KA
    December 8, 2010 at 9:52 pm

    Hi John:
    Sorry, I could have worded that better about the CU.
    Most PC boards for low current circuits use 1/2 mil thick copper, a “mil” being .001″. For heavier current circuits,
    1 or 2 mil CU is used. I think the CCI boards are at least 1 mil, maybe 2, and are of course tin plated.

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