W4RDX called, wanting his Tennadyne T-10 LP repaired, along with a new rotator installation (replacing his third T2X with an HDR-300!).  An “easy enough” gig, one would think, right?

Nice tower, 80-ft of 45G, but simply no room in which to tram down the LP. With careful rigging and slow going, we got it on the ground, all within 64-ft of space. The fix was simple–a bad coax jumper from the balun. However, the rotator shelf was a really old Rohn design, utilizing a round plate held in place by three angle iron braces welded underneath. Of course, that wouldn’t work with the HDR, which mounts from the bottom, just like a prop pitch. So…it required a second trip, with me bringing along an AS455G accessory shelf. Alas, the HDR holes did not mate with the Hy-Gain/CDE bolt pattern. And the MFJ manual contains no template. In desperation, we downloaded one and printed it out. But, as often happens when you print stuff, it wasn’t 100% accurate. At least not accurate enough. The newly-drilled holes were off by about 1/8-inch. I decided not to simply enlarge them, but rather to have a custom shelf made, with the exact spacing, at my local fab shop. This means another trip, but Jim was okay with that.

We thought we’d “check” the HDR as long as we were on-site, too, as Jim had said they had wired things up the previous night, only to find nothing working. We re-traced their steps and had the same outcome. The only solution seemed to be dismantling the brand new rotator. Once we did that, we discovered it was wired incorrectly! More MFJ follies…basically the pot was mis-wired, using pin 8 in the connector, not pin 7. Of course, they only supply seven connector pins, and Jim and friends had USED that little pin already. A quick bit of thinking reminded me the old T2X used all EIGHT pins, and so we cut off that old cable end, and spliced it in line, using a European Molex connector. Voila…success~!

You get the idea…grrrrrrr, good old MFJ…but all’s working as it should. Next trip, we’ll put the rotator itself in place and Jim should be set for several more years of DXing success.

stay tuned…

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