>From: "Geoffrey Thomas" <geoffreythomas(a)onetel.com>
>
>Just remembered - it was the "spontaflex" ,- it was Sir Douglas Hall and
>there is a web page devoted to his circuits.
>Geoff.
>
Hi
A quick search shows that these are at:
http://freespace.virgin.net/spontaflex.reflex/
From looking at some of the text, these are a combination
of a reflex with some regenerative feedback to increase the
Q of the tuning circuits.
I suppose one could write programs to sing through such
a receiver on their clasic computer.
Later
Dwight
Hi,
I'm looking for a Technical Reference manual / schematics for a TRS-80
Model III and the Holmes VID-80 add-on board.
I've found a fair amount on the model I and 4 via Google however there
seems to be nothing on the Model III.
-Neil
I have picked up one of these ATC 510 also ... I have full set of docs for it, all maintenance books and tapes ... I don't recall seeing any charts for it .. but I have not got into all the boxes ... I would love to talk sims or real aviation some time . More than glad to share what I have ,I got this sim given to me from a school that wanted rid of it ... they say it does not work ... if fly's wrong .. but I am pretty sure that I can get it going ... I love to fart around with stuff like that, jeeps me out of trouble.
Anyway drop me line if you like
Mark Jones
MSN messenger - clubwood(a)hotmail.com
>I've got a monochrome NEC APC (dual 8" floppies) that
>I was going to eBay, but it hovers right at that magic
>70lb rate which seems to hit all kinds of shipping
>issues with USPS (won't deliver it), UPS (big $$$
>surcharge), & FedEx (only deliver to a business
>address, $$$). Seems by the time you factor in ship
>costs it wouldn't be worth it unless someone was
>really desperate.
Fedex ground ships to home addresses you know. Price isnt too bad. You could
also try Airborne/DHL or Emery/Menlo worldwide for ideas also.
--
I am not willing to give up my liberties for the appearance of 'security'
(I sent this from the wrong email address last night...oops!)
So, I was hoping to find some sort of manual (any kind) for my TU-81+
via google, but have failed.
So, my TU-81+ doesn't want to power up. I've found the "hidden" power
switch under the cover that I've flipped back and forth a couple of
times, I've made sure the 110/220V jumper was set properly (110V), and
tried different power cords, all to no avail. (I've bypassed the power
controller in the rack and directly hooked the drive to an outlet.)
The power supply "sounds" like it's getting some power when I plug it
in, as I hear a small arc, presumably charging up some capacitors.
However, the fan doesn't start up, and none of the front panel lights.
Does anyone have any suggestions of where to go next? (Tony? :) I
could just start pulling it apart and going through it, but I prefer to
have some direction before I do that.
Pat
--
Purdue University ITAP/RCS --- http://www.itap.purdue.edu/rcs/
The Computer Refuge --- http://computer-refuge.org
Hi
Reading the article by Sir Douglas Hall, he mentions
making an adjustment to keep the positive feedback below
the point of oscillation. This sure sounds like regenerative
to me. Regenerative feedback was used quite often to
increase the effective Q of circuits to increase selectivity.
The article of May 1976 seems to indicate that this is how
this circuit works. This makes sense. There are many, many
ways to introduce regenerative feedback. One of the
early ones was to place a variable coil in the plate
circuit that was not coupled to the tuned input. The
circuit worked by the parasitic capacitance of the triodes
grid to plate. This can be done with a transistor as well.
I remember when I was a kid, I had one of those 2 transistor
reflex receivers made by GE ( wish I still had it ). I
modified it to be regenerative and was able to greatly
extend both range and selectivity. At night, I pulled in
stations across the US.
Dwight
>From: "John Honniball" <coredump(a)gifford.co.uk>
>
>Geoffrey Thomas wrote:
>> Yes, thanks - but the author had a special name for it - that's what I can't
>> remember.
>
>Was it "regenerative"? Or is that a different type of circuit
>altogether? See, for example:
>
> http://www.electronics-tutorials.com/receivers/regen-radio-receiver.htm
>
>--
>John Honniball
>coredump(a)gifford.co.uk
>
The TU81 diag pathfinder and tech manuals are up now on
www.bitsavers.org/pdf/dec/magtape/tu78
The drive itself is an OEMed CDC Keystone, there are some docs
for it under cdc/magtape.
>From: "ben franchuk" <bfranchuk(a)jetnet.ab.ca>
>
>Geoffrey Thomas wrote:
>> Reminds me of the old Radio Constructor designs where the designer made one
>> transistor do both rf and af amplification.
>> Can't remember his name - or what he called his designs.
>> I'm sure he was knighted or something like that .... anybody ?
>> - Sir Alec Douglas Hall ? was it ?
>> Sounds too much like Alec Douglas Hume !
>
>I have no idea who invented it since it was used every where, since the
>humble
>vacume tube ( valve) was invented. You can still buy or build them today.
>
>http://www.vcomp.co.uk/one_tube_1935/one_tube_1935.htm
>http://schmarder.com/radios/tube/index.htm
>Ben.
>
>
Hi
The circuit is called a reflex circuit. The second web page
above shows a tube reflex circuit.
Dwight
Hey Chuck what would one of these things be worth. If it was in great operating condition? Where would a guy find out. MonroeMatic help
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