[10m] Small set-back for the KO6BB/B beacon

[tvsjr at sprynet.com]

One inherent flaw in your logic - you assume that the Mighty Fine Junk antenna analyzer works properly. I'd suggest using a different device to validate the MFJ's analysis... either a Sitemaster/NetTek, a spec-an/tracking generator/return loss bridge, or at the very least an agile radio and a Bird 43 or equivalent wattmeter.

Terry

-----Original Message-----
>From: Philip KO6BB <ndb_fch-344 at sbcglobal.net>
>Sent: Mar 8, 2007 11:17 AM
>To: 10m at mailman.qth.net
>Subject: [10m] Small set-back for the KO6BB/B beacon
>
>Hi All,
>
>The latest project that I've been working on for about a month has a small
>setback.  I'm building a 10 Meter CW beacon.  I gutted a JC Penny 40 Channel
>CB of it's receive and audio circuitry, replaced the final and driver with
>slightly beefier units, beefed up the final heatsink, changed one Xtal,
>added some "keying" circuitry with an RS-232 opto coupler interface and I
>get about 7 Watts of CW out of it. It works well.
>
>It will be keyed from an OLD NEC Pentium laptop running Win95A.  It doesn't
>have enough horsepower or memory (24MB RAM) to use for anything except
>logging and other older, simple programs.  I have a very nice DOS beacon
>keyer program that runs well on it, let's you set up about any message/ID
>pattern that you want and can alternately key at two different speeds
>(presently set about 16 and 6 WPM).  The message I presently have stored in
>it reads "VVV VVV VVV DE KO6BB/B KO6BB/B GRID CM97SF  K".  To prevent wear
>on the Hard-drive I will unplug the drive (slides in) and run the DOS
>program from a floppy.  Both the Radio and computer will run 24/7 off the
>station battery (kept on constant charge).
>
>Anyway, the setback I had concerns the dedicated beacon antenna.  I
>"salvaged" an old Cushcraft Ringo CB antenna, figuring on retuning it for
>10M.  All the fastening hardware was heavily rusted, was cut off and
>replaced with stainless steel hardware.  The "ring" was stress broken right
>at the mounting bolt.  I flattened a half inch and reconnected it.  Since
>the ring is adjustable, and the frequency is now higher I figured that
>wouldn't hurt it any. After reassembly, adjusting the length according to
>the Cushcraft instructions etc. I checked it with a friends MFJ antenna
>analyzer.  It was nicely tuned to 24.6 MCs!  I collapsed some of the
>sections to shorten the antenna.  NO effect on antenna tuning!! It's been
>checked and rechecked, just doesn't make any sense, other than that perhaps
>the CBer had already shortened the ring or something. . .  I'm apparently
>seeing the resonant point of the ring rather than the antenna proper.  In
>any case,  I gave up on getting that thing tuned to 10M.  I'm keeping the
>aluminum though.  If I remove the ring and add radials (or use it over my
>metal roof) it can be made into a 1/4 wave vertical for any one band from
>20-10M.  I'm going to try to get a Solarcon A-99 (1/2 wave fiberglass
>vertical) for the 10M beacon, hopefully later this month.
>
>73 de Phil,  KO6BB
>DX begins at the noise floor!
>
>THE BEACONEER'S LAIR:   http://www.geocities.com/ko6bb/
>MY RADIO-LOGS:       http://www.geocities.com/ko6bb/Logs/
>QSL GALLERY: http://photobucket.com/albums/f306/KO6BB/
>Merced, Central California,    37.3N  120.48W  CM97sh
>
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