Arfa Daily wrote:
"Mark Zenier" wrote in message
...
In article
,
Ron wrote:
In the case of the "haunted" tape recorder, the RF
probably leaked into the microphone circuitry; the recording
electronics "detected" the audio and mixed it with what you were
saying and then recorded the combined signal onto the tape.
Hmmm.... in this case, the signals weren't combined: the extraneous
signal totally wiped out what I had taped for about twenty seconds.
And what I don't get is-- well, there are a couple of things that I
don't get now that I think about it.
First, is where such a signal would come from. There are no hams or
other sources close by. As many times as I have made tapes over the
years, this is the only time such a thing has happened.
First, a radio ham, with a transmitter powerful enough to mess
with your recorder would, in the vast majority of cases, be using
Single Side Band modulation and would sound like Donald Duck on
steroids.
So either somebody found your recorder, and was messing with your
head by recording something over top your recording, between the
time you made it and then listened to it. Or the erase head in
the recorder is flaky and that was what was on the tape beforehand.
Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)
There's been quite a revival of interest in AM in some parts, particularly
on topband. AM transmissions are readily demodulated by base - emitter
transistor junctions, or amplifier stages driven to non-linearity by such
signals. Also, a powerful FM transmitter can be 'received' on a tape
recorder, by the signal getting into, and beating with, the bias oscillator.
The bias oscillator's L-C tuned circuit may also operate as a form of simple
slope detector. So although I agree that the commonest high power mode is
SSB, this by no means rules out a different mode, quite possibly generated
by a ham radio operator.
Arfa
On this side of the pond, it's CB operators (it's hard to actually call
them 'operators', but for the lack of a better word....). They often
use AM, and they're famous for their lack of technical ability. They
often use illegal high power amplifiers. Many have a total disregard
for any ill-effect of their silly games.
Any signal strong enough can totally swamp everything else in the
recorder circuitry, leaving the detected signal on the tape.
jak