[Boatanchors] Receiver Technology

Mon Jan 17 13:44:34 EST 2011

Hertz got started on RF by accident also but a different sort.
He was looking for a research grant and found one. The question was, does the apparent current thru a capacitor's dielectric or even air produce a magnetic field.  This was the goal but by coming up with ways to try to measure such a field he discovered waves and even though his grant was for a specific measurement he diverted all his efforts to studying these waves.  He even built a very large prism to see if these waves were refracted just as light waves. It was a very large wooden container filled with pitch.  It had to be so large because it had to be much larger than a wavelength of these waves which was around a meter or so. 
Imagine what that cost. Just in materials alone. He used parabolic reflectors to create more intense waves and made all sorts of measurements.  
    There are professional researchers that stay on track and are not derailed by something interesting but sometimes there is a benefit for all of us when they do get derailed.  

73
Bill wa4lav________________________________________
From: J. Forster [jfor at quik.com]
Sent: Monday, January 17, 2011 1:23 PM
To: Fuqua, Bill L
Cc: ka9egw at britewerkz.com; George Babits; Boatanchors List
Subject: Re: [Boatanchors] Receiver Technology

You can easily see this today, although few recognize it.

If you have an old instrument or especially a power strip with a Ne pilot
light, the pilot often will not glow or will flicker in a dark room. If
you turn on the room lights or shine a flash light on the Ne bulb, it will
glow continuously.

The optical photons kick-start the ionization process.

Best,

-John

==============

> It was an accident. He actually discovered the photoelectric effect.
> He was working with his detector and was getting odd results.
> It would spark at a wider gap than it should have. He then discovered it
> was the light
> coming thru a window and filtered out various wavelengths of light and
> found it was
> UV.  All before 1900.
> Bill
> ________________________________________
> From: ka9egw at britewerkz.com [ka9egw at britewerkz.com]
> Sent: Monday, January 17, 2011 4:44 AM
> To: Fuqua, Bill L; George Babits
> Cc: Boatanchors List
> Subject: RE: [Boatanchors] Receiver Technology
>
> You've piqued my curiosity.  The dictionary defines "Hertz Effect" as:
> [1] Increase in the length of a spark induced across a spark gap when the
> gap is irradiated with ultraviolet light.
> (electromagnetism)
> [2] A dependence of the attenuation of a linearly polarized
> electromagnetic
> wave passing through a grating of metal rods on the angle between the
> electric vector and the rod direction, with the attenuation being a
> minimum
> when the two are perpendicular.
>
> I'm wondering what Hertz used as a UV source?  Or are we talking the
> second
> definition here?
>
> 73, Brian KA9EGW
>
> -----Original Message-----
> From: boatanchors-bounces at puck.nether.net
> [mailto:boatanchors-bounces at puck.nether.net]On Behalf Of Fuqua, Bill L
> Sent: Sunday, January 16, 2011 11:51 PM
> To: George Babits
> Cc: Boatanchors List
> Subject: Re: [Boatanchors] Receiver Technology
>
>
> Well, George, it looks like no one has anything to offer about boatanchor
> receiver design.
> They want to argue about ARRL. I'd rather talk about early 1920's
> receivers
> and even those
> before. It seems to me that people had problems breaking old habits, such
> as
> single conversion
> designs with low frequency IF. A good receiver had to have 2 RF amplifiers
> for image rejection.
>    I am still impressed by some of the knowledge they had in the early
> spark
> era. Many had a good
> understanding of resonance and impedance matching. Look at what Hertz
> accomplised. I bet very
> few know what the "Hertz Effect" is. He discovered it by accident while
> doing his RF experiments  using
> a calibrated spark gap as a receiver. He made the first Beam antenna. Now
> today most people think beam
> antenna means Yagi but any antenna that produces a "beam" is a beam
> antenna.
> He uses a parabolic
> reflector in some experiments.
>
> 73
> Bill wa4lav
>
> ________________________________________
> From: George Babits [gbabits at custertel.net]
> Sent: Sunday, January 16, 2011 2:40 PM
> To: Fuqua, Bill L
> Cc: Boatanchors List
> Subject: Re: [Boatanchors] Receiver Technology
>
> Speaking of converters - -look at the old pictures of ham stations in the
> late 1940's and 50's QSTs.  One of the things you will see is a lot of RME
> HF-10/20 converters ahead of a  fairly decent receivers.  Those converters
> are really something.  I hooked one up ahead of a BC-224B (12 volt version
> of BC-348) last fall and the DX really jumped out of the noise.  I was
> somewhat astounded.  Now I know why my "mentor,"  Pete W0JYW, used one
> ahead
> of his HQ-129X back in 1957.  RME's VHF-152 is a pretty hot (relatively)
> converter as well.
>
>   As for ARRL and QST, they both serve a purpose, but there is little of
> interest to the builder or boat anchor fan.  That is probably where the
> rub
> is.  We need to remember that they did pretty much "save" amateur radio
> after both WW-I and WW-II.   I'm an avid boat anchorite and builder so QST
> has nothing for me.  Oh well; such is life.
>
> Keep the filaments lit,
> George
> W7HDL
>
>
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