Strange anomalies occuring in San Antonio...
On a recent trip back to San Antonio from New Orleans, I stopped in at
my buddy WA5BXO/John's place, in Spring, TX, and picked up some personal
stuff that was there. One of the items was my Sure SM-7 microphone. I
was anxious to plug the balanced audio output of the mic, back into the
31-band Graphic equalizer, feed the balanced output into my
balanced-input, highly modified Bogen PA system that's being used at a
speech-amp and get on the air with some 'big' audio.
All was great. Audio sounded fabulous, reports were glowing with praise
and the positive/negative peak ratio was pushing 4:1 on the 'scope.
Good thing I'm only running 100w of carrier output on the rig, eh?
Anymore, and a 4:1 ratio would mean I was running more than 1,500w PEP.
(www.qsl.net/wa5bxo/asyam/aam3.html)
Anyway - all was great. I was up early (3:am or so) and was on 3.885
calling "CQ 75m Fone". No answer. Did some more testing, adjusting,
tweaking and even tried the big Western Electric Ribbon microphone
(there's three inputs, and a JT-30 is on #3 input, the EQ output is on
#2) but input #1 on the Bogen has a problem so, I just turned it down,
and didn't bother with the big mic. Problem is probably a bum 6EU7.
Then, along around 3:47am the phone rings...
A sleepy-sounding gal asks "did someone call me from this number?"
CallerID had her placed South of town - I could tell by the prefix) and
I said, "sorry - we don't call people at 4am, unless there's an
emergency, and there's nothing going on, here..." "ok, thank you".
I hung up, went back to working on the audio, again. Got in a QSO
around 5am and all was great. Signals were up, conditions were good,
reports were glowing.
Around 7:15am, there was a *tap* *tap* *tap* on the shack door. I
thought "huh? Who would be here at 7:15am, on a Sunday morning?"
When I got to the door, there was a big ol' COP out there. Now, when I
say big, I'm 6'3" and 260, and this guy was head and shoulders taller
than I am!
He asks: "is everything ok, here?"
I looked at him, kinda incredulously... "yeah, all's fine. Why? What's
the matter?"
He says: "We recieved a Nine one one call, from this residence."
I immediately assure him that there's nothing wrong, and I say 'hang on
a sec" and go back to check on my aged mother, who's laying in her bed,
sounding like she's sawing Big Redwood trees into kindling. She's fine
and I go back to the cop and say "man, everything here is fine. Do you
know who called?"
He says the call was placed -from- the residence. I ask him "what
time?" He calls the dispatcher and she says that the call came in at
7:05am - they showed up at 7:15am.
When they (there's two, by now) are satisfied that all is great, he says
"you're a radio operator?" peering over my shoulder, looking at the rig
and all
(http://w5omr.shacknet.nu/~w5omr/hamstuff/My%20Junque/hamshack-1July2005/2005-07-08/100_0061.JPG)
and I invite him in. I go on to tell him about all the neat things that
Hams, in general, do; how we're able to talk to the Space shuttle (since
it's up there, right now and is a current event topic); all the
emergency communications; how hams were the first responders to the
September 11th disaster; how when there's no power or electricity from a
flood, hurricane, earthquake, or other natural disasters that Hams are
the first ones on the scene, provind communications with emergecy power,
portable antennas etc... and then go on to explain about my affliction
with old-tyme radios and how I *could* spend upwards of $10,000 dollars
for a commercially built radio, but that I could build one myself that
does basically the same thing, because when you boil it all down, all
you need to be able to do, is talk to the person on the other end, and
hear him talking back to you, and building something that works from
parts, instills a lot of pride, and that there were other people who
shared the same interest. I compared it to driving a kit-car (that you
build) as opposed to picking one up off the showroom floor. The analogy
was good, because it worked.
The nice police officer agreed that it was a neat thing, he was
impressed with it all, thanked me for my time, and he and his partner
went on about other more serious (I'm sure) affairs.
In the mean time, I'm wondering "what in the world is going on with this
damn rig?" and the first thing I do, is install a low-pass filter on the
output of the rig (that I -thought- was in-line, but wasn't). I don't
think it makes much difference, but it's there anyway and I'm still in a
quandry.
So, when I'm faced with an electronic puzzlement, especially RF related,
I call my friend/mentor/AM Elmer, John/WA5BXO.
He goes on to tell me about how he, Otis and Candy/K5IYW, back in the
old days, had an Elvis style, Sure 55S microphone (which now houses the
dual condensor mic elements with 4 LED's in a picture John had up here
in the Reflector yesterday) that had just the slightest RF feedback in
it... not enough to hear, but enough to go through the rig, and it was
because of the magnetic pick-up in the mic. Perhaps John will weigh in
here and straighten that story out (I hope so, anyway). He said, that
because of the feed-back, there were parasitics and birdies up and down
the band, around ever 20kc or so, from the fundamental frequency.
I guess it's all possible. I've heard my dad tell tales about how his
BC-610 had the metal grills in an oven in a house that was two doors
down, 'talking'. The grill was apparently resonat with the carrier
frequency, and you could hear the audio on the carrier. She was a
little embarrassed about it, because she heard his voice in her oven,
when she came out of the shower, the first time. Dad 'tweaked' the
grill a little, took it out of resonance, and the problem never came back.
The thing that has me puzzled most, is that somehow the rig had to take
the phone off the hook, THEN dial out. The switch is a mechanical device.
(insert Twilight
Zone music, here)
It had to be dialing random numbers. I had never seen the number/name
of the person that called at 3:347am.
I wonder if there were any long distance numbers dialed? ;-)
Come to think of it, I had disconnected and put back on a shelf, the big
Western Electric Ribbon mic, AFTER the police showed up. It certainly
has a big horse-shoe magnet in it, but that input was at minimum,
because it doesn't work.
Curiouser and Curiouser
Such is life here, at W5OMR
Any ideas/thoughts/comments?
---
73 = Best Regards,
-Geoff/W5OMR