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"Sir Charles W. Shults III" <aichip@cfl.rr.com> wrote in message news:<m%E58.483404$oj3.91200781@typhoon.tampabay.rr.com>...
Well, I have been a long time reader and subscriber to another venerable
magazine- Scientific American. This year, however, I have dropped my
subscription with no plans to renew. They, too, have changed format in a
attempt to get a new and different audience. The new format truly sucks.
They removed the "Amateur Scientist" column, which was an excellent
source of hands-on material for me as a kid, and lots of fun to read until
its death. They have "prettied up" the interior of the magazine with lots
of computer graphics, but at a loss of clarity. The older, hand drawn black
and white pictures had a charm of their own and got the message across
perfectly well.
Also, they have dropped to about half of their original thickness. The
excellent articles of the past are just that- of the past. Surely we have
not stopped producing science?
Cheers!
Do you remember when Gernsback (the company) had a science magazine?
I was thinking about it in this thread, and then when looking for
something, found one of the copies I have.
It was called "Science Probe" and was subtitled, "The Amateur Scientist's
Journal". The editor was Forest M. Mims III, and it seems the first
issue was July 1991. I have the October 1991 issue. I can't remember
how long it existed, but it wasn't all that long.
Think of Popular Electronics, the Gernsback version not the original,
where instead of dealing with electronics, science is the territory.
So there are columns, and special features (like articles about
science fairs) and then the "construction articles", ie hands-on
projects that teach while you try out the experiments.
It seemed intended for the hobby scientist and the young, rather
than the focus of something like Scientific American where the bulk
is articles you simply read, with a few hands-on columns (most noteably,
The Amateur Scientist).
I only bought a few issues, because it by the time it came out,
I had long lost a lot of interest in science in general (or at least,
reading about it), but it would have been a great magazine to read when
I was younger. The fact that it didn't last that long, I suppose
that's a reflection of what interests people. On the other hand,
how can you get the young interested if there aren't magazines
like this around?
Michael
"Sir Charles W. Shults III" <aichip@cfl.rr.com> wrote in message
news:m%E58.483404$oj3.91200781@typhoon.tampabay.rr.com...
Well, I have been a long time reader and subscriber to another
venerable
magazine- Scientific American. This year, however, I have dropped my
subscription with no plans to renew. They, too, have changed format in a
attempt to get a new and different audience. The new format truly sucks.
They removed the "Amateur Scientist" column, which was an excellent
source of hands-on material for me as a kid, and lots of fun to read until
its death. They have "prettied up" the interior of the magazine with lots
of computer graphics, but at a loss of clarity. The older, hand drawn
black
and white pictures had a charm of their own and got the message across
perfectly well.
Also, they have dropped to about half of their original thickness.
The excellent articles of the past are just that- of the past. Surely we
have not stopped producing science?
New Scientist mag is still pretty much the same quality it's always been,
though it did go through a very bad patch in the early 70's when the Loony
Left got hold of it for a while.
Dirk Bruere wrote:
New Scientist mag is still pretty much the same quality it's always been,
though it did go through a very bad patch in the early 70's when the Loony
Left got hold of it for a while.
New Scientist is still pretty much a tabloid of the Loony Left... they
never miss a chance to criticize US environmental policies, and they
don't mind manufacturing those chances out of whole cloth, sort of like
John Goodman's incessant invocations of Viet Nam in 'The Big Lebowski'.
But I find it makes for good bathroom reading.
I don't think I've picked up an issue of SciAm for ten years.
Hi Joerg.
I have some strange problem with my setup ( Arduino --> Raspberry ).
The system is working perfect but after minute or two, i get HIGH state
on RSP pin, but nothing wasn't sent from arduino. I get this states all
the time and i can not stop them. They are activated at random cycles.
The funny part is that i can not detect any voltage change ( when this
error starts ) and according to the datasheet, voltage from 2.8 - 3.3 is
defined as HIGH state.
So, is it possible that RSP is picking some fast impulse from arduino's
voltage divider ?
GM
Looking for a tube only radio or radio kit
AM or FM or AM FM
More than standard broadcast range is desirable.
On Sunday, June 12, 2016 at 6:20:14 PM UTC-4, gm wrote:
Hi Joerg.
I have some strange problem with my setup ( Arduino --> Raspberry ).
The system is working perfect but after minute or two, i get HIGH state
on RSP pin, but nothing wasn't sent from arduino. I get this states all
the time and i can not stop them. They are activated at random cycles.
The funny part is that i can not detect any voltage change ( when this
error starts ) and according to the datasheet, voltage from 2.8 - 3.3 is
defined as HIGH state.
So, is it possible that RSP is picking some fast impulse from arduino's
voltage divider ?
GM
On 06/13/2016 09:16 PM, makolber@yahoo.com wrote:
On Sunday, June 12, 2016 at 6:20:14 PM UTC-4, gm wrote:
Hi Joerg.
I have some strange problem with my setup ( Arduino --> Raspberry ).
The system is working perfect but after minute or two, i get HIGH state
on RSP pin, but nothing wasn't sent from arduino. I get this states all
the time and i can not stop them. They are activated at random cycles.
The funny part is that i can not detect any voltage change ( when this
error starts ) and according to the datasheet, voltage from 2.8 - 3.3 is
defined as HIGH state.
So, is it possible that RSP is picking some fast impulse from arduino's
voltage divider ?
GM
open CMOS input?
maybe... Good idea.
On 06/14/2016 03:35 PM, Dan wrote:
Looking for a tube only radio or radio kit
AM or FM or AM FM
More than standard broadcast range is desirable.
You can build a single-tube regenerative set that, if designed and
constructed carefully, will have much better performance over the AM and
AM shortwave bands than many commercially available superhets.
On Wednesday, 15 June 2016 15:09:17 UTC+1, bitrex wrote:
On 06/14/2016 03:35 PM, Dan wrote:
Looking for a tube only radio or radio kit AM or FM or AM FM More
than standard broadcast range is desirable.
You can build a single-tube regenerative set that, if designed and
constructed carefully, will have much better performance over the
AM and AM shortwave bands than many commercially available
superhets.
That's at odds with my own limited experience with reaction sets, and
with people's experiences of commercial regen receiver ICs. They do
remarkably well for the small number of parts, but don't compare in
rf sensitivity to typical modern superhets. They are dramatically
better at AGC though.
ISTR seeing tube circuits that were superhets with a reaction IF
stage.
On 15/06/2016 15:33, tabbypurr wrote:
On Wednesday, 15 June 2016 15:09:17 UTC+1, bitrex wrote:
On 06/14/2016 03:35 PM, Dan wrote:
Looking for a tube only radio or radio kit
AM or FM or AM FM
More than standard broadcast range is desirable.
You can build a single-tube regenerative set that, if designed and
constructed carefully, will have much better performance over the AM and
AM shortwave bands than many commercially available superhets.
That's at odds with my own limited experience with reaction sets, and with people's experiences of commercial regen receiver ICs. They do remarkably well for the small number of parts, but don't compare in rf sensitivity to typical modern superhets. They are dramatically better at AGC though.
ISTR seeing tube circuits that were superhets with a reaction IF stage.
Yes, I believe a regenerative detector following a frequency changer
(aka mixer) is called "supergainer".
I have never tried a supergainer but always liked the idea of compromise
best-of-both-worlds?
piglet
On Wednesday, 15 June 2016 15:09:17 UTC+1, bitrex wrote:
On 06/14/2016 03:35 PM, Dan wrote:
Looking for a tube only radio or radio kit
AM or FM or AM FM
More than standard broadcast range is desirable.
You can build a single-tube regenerative set that, if designed and
constructed carefully, will have much better performance over the AM and
AM shortwave bands than many commercially available superhets.
That's at odds with my own limited experience with reaction sets, and with people's experiences of commercial regen receiver ICs. They do remarkably well for the small number of parts, but don't compare in rf sensitivity to typical modern superhets. They are dramatically better at AGC though.
ISTR seeing tube circuits that were superhets with a reaction IF stage.
NT
On Thursday, 16 June 2016 20:30:44 UTC+1, piglet wrote:
On 15/06/2016 15:33, tabbypurr wrote:
On Wednesday, 15 June 2016 15:09:17 UTC+1, bitrex wrote:
On 06/14/2016 03:35 PM, Dan wrote:
Looking for a tube only radio or radio kit
AM or FM or AM FM
More than standard broadcast range is desirable.
You can build a single-tube regenerative set that, if designed and
constructed carefully, will have much better performance over the AM and
AM shortwave bands than many commercially available superhets.
That's at odds with my own limited experience with reaction sets, and with people's experiences of commercial regen receiver ICs. They do remarkably well for the small number of parts, but don't compare in rf sensitivity to typical modern superhets. They are dramatically better at AGC though.
ISTR seeing tube circuits that were superhets with a reaction IF stage.
Yes, I believe a regenerative detector following a frequency changer
(aka mixer) is called "supergainer".
I have never tried a supergainer but always liked the idea of compromise
best-of-both-worlds?
piglet
Because the reaction is fixed frequency, it seldom needs much adjustment. I've not tried one either. Prewar radio is fun.
NT
On 15/06/2016 15:33, tabbypurr@gmail.com wrote:
On Wednesday, 15 June 2016 15:09:17 UTC+1, bitrex wrote:
On 06/14/2016 03:35 PM, Dan wrote:
Looking for a tube only radio or radio kit
AM or FM or AM FM
More than standard broadcast range is desirable.
You can build a single-tube regenerative set that, if designed and
constructed carefully, will have much better performance over the AM and
AM shortwave bands than many commercially available superhets.
That's at odds with my own limited experience with reaction sets, and
with people's experiences of commercial regen receiver ICs. They do
remarkably well for the small number of parts, but don't compare in rf
sensitivity to typical modern superhets. They are dramatically better
at AGC though.
ISTR seeing tube circuits that were superhets with a reaction IF stage.
NT
Yes, I believe a regenerative detector following a frequency changer
(aka mixer) is called "supergainer".
I have never tried a supergainer but always liked the idea of compromise
best-of-both-worlds?
piglet
On 06/16/2016 03:30 PM, piglet wrote:
On 15/06/2016 15:33, tabbypurr@gmail.com wrote:
On Wednesday, 15 June 2016 15:09:17 UTC+1, bitrex wrote:
On 06/14/2016 03:35 PM, Dan wrote:
Looking for a tube only radio or radio kit
AM or FM or AM FM
More than standard broadcast range is desirable.
You can build a single-tube regenerative set that, if designed and
constructed carefully, will have much better performance over the AM and
AM shortwave bands than many commercially available superhets.
That's at odds with my own limited experience with reaction sets, and
with people's experiences of commercial regen receiver ICs. They do
remarkably well for the small number of parts, but don't compare in rf
sensitivity to typical modern superhets. They are dramatically better
at AGC though.
ISTR seeing tube circuits that were superhets with a reaction IF stage.
NT
Yes, I believe a regenerative detector following a frequency changer
(aka mixer) is called "supergainer".
I have never tried a supergainer but always liked the idea of compromise
best-of-both-worlds?
piglet
Interestingly the "super" in both "superregenerative" and
"superheterodyne" comes from "supersonic", which before the 1950s meant
"too high-pitched to hear", i.e. ultrasonic. You need the IF and the
quench frequency to be above audio.
Cheers
Phil Hobbs
The "supergainers" I heard of were not super-regenerative. Just a
superhet type front end frequency changer and a regenerative
("reaction") i.f. stage,
On 06/16/2016 03:30 PM, piglet wrote:
On 15/06/2016 15:33, tabbypurr wrote:
On Wednesday, 15 June 2016 15:09:17 UTC+1, bitrex wrote:
On 06/14/2016 03:35 PM, Dan wrote:
Looking for a tube only radio or radio kit
AM or FM or AM FM
More than standard broadcast range is desirable.
You can build a single-tube regenerative set that, if designed and
constructed carefully, will have much better performance over the AM and
AM shortwave bands than many commercially available superhets.
That's at odds with my own limited experience with reaction sets, and
with people's experiences of commercial regen receiver ICs. They do
remarkably well for the small number of parts, but don't compare in rf
sensitivity to typical modern superhets. They are dramatically better
at AGC though.
ISTR seeing tube circuits that were superhets with a reaction IF stage.
Yes, I believe a regenerative detector following a frequency changer
(aka mixer) is called "supergainer".
I have never tried a supergainer but always liked the idea of compromise
best-of-both-worlds?
Interestingly the "super" in both "superregenerative" and
"superheterodyne" comes from "supersonic", which before the 1950s meant
"too high-pitched to hear", i.e. ultrasonic. You need the IF and the
quench frequency to be above audio.
Sorry Phil but I must query your statement "If it oscillates, then
either it's a superregen or it's broken".
I would rather say that if it oscillates then it is an oscillating
regenerative detector. It is super-regenerative only if that
self-oscillation is itself periodic, whether by squegging or by a
separate quench oscillator.
The quenching occuring at neither r.f. nor a.f. but a super-sonic rate
is where the prefix super comes in.
I have built both regenerative radios and super-regenerative radios and
there is a definite difference. My copy of Terman Radio Engineering 2nd
ed 1937 also makes the distinction clear, see section 89 p453-456 and
section 90 p456-459.
The "supergainers" I heard of were not super-regenerative. Just a
superhet type front end frequency changer and a regenerative
("reaction") i.f. stage,
Well, if a regenerative stage doesn't oscillate, it's basically a Q-multiplier. That's more of an HF front end idea, though. If it oscillates, then either it's a superregen or it's broken.
You can make a 1-tube superregen by making the grid time constant long, so that it squegs. The squegging supplies the quench for the superregen.
Cheers
Phil Hobbs
The "supergainers" I heard of were not super-regenerative. Just a
superhet type front end frequency changer and a regenerative
("reaction") i.f. stage, so only two frequencies in the system: signal
and i.f. There was no third frequency/ultra-sonic quenching, the i.f.
stage was merely steadily self oscillating like a regular plain regen
receiver, so had remarkable q-multiplier type selectivity but not the
extreme gain of a super-regen.
piglet
A straight regenerative receiver is an amplifying stage with positive
feedback and should be be adjusted so it is just below the point
of oscillation - the positive feedback increases the gain
over that of a straight stage and can improve selectivity. It should
not radiate if correctly used.