Driver to drive?

[Phil Hobbs]

On 06/17/2016 04:37 AM, piglet wrote:

On 17/06/2016 03:28, Phil Hobbs wrote:
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


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.

piglet


Page 575 in my 1943 edition.

Ah, OK, they're running it as an oscillator with nearly unity
small-signal loop gain and looking at the oscillation amplitude.

You sure couldn't do that in a TRF.

Thanks

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

 

[Tauno Voipio]

On 17.6.16 17:39, Phil Hobbs wrote:

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.

That's a Q-multiplier, not a detector, though. Q multipliers are noisy, but you don't care very much at MF/HF.

Cheers

Phil Hobbs

It depends on the biasing of the tube. Capacitive coupling, together
with a largish resistor to goround (grid leak) create a grid-leak
detector, and its gain can be improved with positive feedback.

The grid-cathode diode is the primary detection element, and the
incoming AM modulation can be retrieved from plate current (or voltage,
if there is a suitable plate feed resistor).

--

-TV

 

On Friday, 17 June 2016 15:39:17 UTC+1, Phil Hobbs wrote:

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.

That's a Q-multiplier, not a detector, though. Q multipliers are noisy, but you don't care very much at MF/HF.

Detection is achieved by a little nonlinearity in the stage.


NT

 

[kevin93]

On Friday, June 17, 2016 at 7:39:17 AM UTC-7, Phil Hobbs wrote:
....

That's a Q-multiplier, not a detector, though. Q multipliers are noisy, but you don't care very much at MF/HF.

Cheers

Phil Hobbs

It depends upon which frequency you expect as output from the stage.

If you extract the output at the RF frequency, yes it is a Q multiplier.

If you extract the audio that results from non-linearity in the active device then it is a regenerative detector.

That was an extremely common arrangement until superhets became common.

kevin

 

[Phil Hobbs]

Using a Q-multiplier as a detector sounds pretty far fetched to me. Any published examples? (I don't regard myself as an expert on early radio, but I've studied it because there are a lot of similarities with modern optics.)

Cheers

Phil Hobbs

 

[kevin93]

On Friday, June 17, 2016 at 5:02:05 PM UTC-7, Phil Hobbs wrote:

Using a Q-multiplier as a detector sounds pretty far fetched to me. Any published examples? (I don't regard myself as an expert on early radio, but I've studied it because there are a lot of similarities with modern optics.)

Cheers

Phil Hobbs

This link is good one describing Armstrong's original circuit:

http://thesilicongraybeard.blogspot.com/2014/02/techy-tuesday-100-years-ago.html

A more modern example using a BJT - interestingly this one is based on a Colpitts configuration.

http://www.ke3ij.com/AGC-80.htm

These searches through Google bring up a number of schematics:

"single transistor regenerative receiver schematic"
"single valve regenerative receiver schematic"

kevin

 

On Saturday, 18 June 2016 01:02:05 UTC+1, Phil Hobbs wrote:

> Using a Q-multiplier as a detector sounds pretty far fetched to me. Any published examples? (I don't regard myself as an expert on early radio, but I've studied it because there are a lot of similarities with modern optics.)

It was the most common radio configuration during the 1930s.


NT

 

[Tauno Voipio]

On 18.6.16 03:01, Phil Hobbs wrote:

Using a Q-multiplier as a detector sounds pretty far fetched to me. Any published examples? (I don't regard myself as an expert on early radio, but I've studied it because there are a lot of similarities with modern optics.)

Cheers

Phil Hobbs

Get any tube-era ARRL Handbook (the older ones are called The Radio
Amateur's Handbook). There is a long explanation on grid-leak detectors
with and without feedback.

My first ham receiver was an old one built around 1947, a superhet with
a fed-back grid-leak detector after the first and only IF transformer.
For AM, the detector was run just below oscillation point, and for CW
(Morse with just on-off carrier), it was run oscillating and providing
the necessary beat frequency to hear the signals.

--

-TV

 

On Monday, 20 June 2016 01:45:08 UTC+1, Bennett Price wrote:

On 6/19/2016 3:52 PM, Tom Del Rosso wrote:
Dan wrote:
Looking for a tube only radio or radio kit
AM or FM or AM FM
More than standard broadcast range is desirable.

I tried finding one that used transistors and no all-in-one radio chip,
and turned up nothing.



Ebay has some AM transistor radio kits, i.e., unbuilt
http://ebay.to/1UiPPFA

as well as a variety of tube radios (AM, AM-FM. & AM-FM-SW), all built

and some AM tube kits http://ebay.to/1UiOXAN

one of which - a 7 tube AM radio - for $9 features:

two in the discharge standard circuit;
Modulated at 465KHz
Plastic shell for the new material, and never go back to feeding.
Each test port circuit Ic levels.
Schematics, assembly drawings, and the other parts list, technical
documents are complete.

Despite the description, it uses transistors, not tubes.

I doubt you'd find a tube radio kit anywhere, too unpopular and too much worry about liability for anything over 50v. And of course reaction adjusted by the user is a no-no now.


NT

 

[kevin93]

On Tuesday, June 14, 2016 at 12:35:21 PM UTC-7, Dan wrote:

Looking for a tube only radio or radio kit
AM or FM or AM FM
More than standard broadcast range is desirable.

Try here:

http://www.6v6.co.uk/kits.html

kevin

 

On Friday, December 21, 2012 at 12:52:17 PM UTC+11, John Larkin wrote:

On Thu, 20 Dec 2012 17:17:05 -0800 (PST), RichD
r_delaney2001@yahoo.com> wrote:

Perhaps there will be warming, but not overheating:

http://tinyurl.com/wsj-ridley-on-GW

1.6* C seems survivable, maybe even benign.

John Larkin keeps on believing everything he gets told on denialist web sites.
In reality we've already had enough global warming to get more "extreme weather events" than we used to, and rainfall patterns are starting to move around.

More CO2, a bit warmer and wetter, great for crops. Add fracking and
various technologies, and genetic breakthroughs, and we have a Golden
Age.

Ask any denialist web-site. A couple of weeks ago Sydney had a particuarly intense "east coast low" and got 200mm of rain in 24 hours. The accompanying waves dug out a big stretch of beach, and there was a dramatic picture of what had been somebody's swimming pool sitting down on the beach. The houses themselves hadn't been affected, this time around, but their back yards were shorter.

Ridley isn't a scientist, but he does cite credible
sources.

http://www.sourcewatch.org/index.php/Matt_Ridley

He makes loads of money out of the opencast coal mines on his estate, and is certified denialist - of the luke-warm persuasion.

The Wall Street Journal - like most of the Murdoch media - publishes a lot of denialist propaganda as if were objective news

Of course, we know Sam Wormley will give this
due consideration, famous as he is for rationality
and objectivity and erudition, immune to hysteria
and ego and emotional investment.

PS Epigram from the article: "... given the IPCC's
record of replacing evidence-based policy-making
with policy-based evidence-making..."

Good line.

Inaccurate to the point of being an outright lie, but great denialist propaganda.

There are still people claiming that the entire human species will be
eliminated by AGW.

Only a lunatic fringe. A human population crash is a lot more plausible, but even that depends on the gullible - like John Larkin - blocking effective action until it's way too late.

--
Bill Sloman, Sydney

 

[JW]

On Fri, 1 Jul 2016 03:26:14 -0700 (PDT) bill.sloman@ieee.org wrote in
Message id: <5cb1b842-1a5d-41ea-a940-df4e3b680e2b@googlegroups.com>:

>On Friday, December 21, 2012 at 12:52:17 PM UTC+11, John Larkin wrote:

A bit late on this one, aren't you?

 

[John Larkin]

On Fri, 01 Jul 2016 09:40:10 -0400, JW <none@dev.null> wrote:

On Fri, 1 Jul 2016 03:26:14 -0700 (PDT) bill.sloman@ieee.org wrote in
Message id: <5cb1b842-1a5d-41ea-a940-df4e3b680e2b@googlegroups.com>:

On Friday, December 21, 2012 at 12:52:17 PM UTC+11, John Larkin wrote:

A bit late on this one, aren't you?

Sloman operates on a different time scale from the rest of us.

A different emotional scale, too.

(And I sense the beginnings of a turnaround on the insane AGW thing.
People are looking at the facts at last: our biggest hazard is the
possible solar-minimum mini-ice age starting soon. I'd prefer
warming.)


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Jim Thompson]

On Fri, 01 Jul 2016 09:40:10 -0400, JW <none@dev.null> wrote:

On Fri, 1 Jul 2016 03:26:14 -0700 (PDT) bill.sloman@ieee.org wrote in
Message id: <5cb1b842-1a5d-41ea-a940-df4e3b680e2b@googlegroups.com>:

On Friday, December 21, 2012 at 12:52:17 PM UTC+11, John Larkin wrote:

A bit late on this one, aren't you?

Slowman is noted for his mental slowness and sloth-appeal >:-}

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I'm looking for work... see my website.

 

On Friday, July 1, 2016 at 11:40:13 PM UTC+10, JW wrote:

On Fri, 1 Jul 2016 03:26:14 -0700 (PDT) bill.sloman@ieee.org wrote in
Message id: <5cb1b842-1a5d-41ea-a940-df4e3b680e2b@googlegroups.com>:

On Friday, December 21, 2012 at 12:52:17 PM UTC+11, John Larkin wrote:

A bit late on this one, aren't you?

It popped up on google gropus as if it were a current thread, and I didn't pay any attention to the date until after I'd posted my habitual response.

That's embarrassing. I can defend myself with the observation that John Larkin has been posting links to much the same kind of nonsense pretty regularly since 2012, and my response is habituated.

--
Bill Sloman, Sydney

 

On Saturday, July 2, 2016 at 12:52:43 AM UTC+10, John Larkin wrote:

On Fri, 01 Jul 2016 09:40:10 -0400, JW <none@dev.null> wrote:

On Fri, 1 Jul 2016 03:26:14 -0700 (PDT) bill.sloman@ieee.org wrote in
Message id: <5cb1b842-1a5d-41ea-a940-df4e3b680e2b@googlegroups.com>:

On Friday, December 21, 2012 at 12:52:17 PM UTC+11, John Larkin wrote:

A bit late on this one, aren't you?

Sloman operates on a different time scale from the rest of us.

A different emotional scale, too.

(And I sense the beginnings of a turnaround on the insane AGW thing.
People are looking at the facts at last: our biggest hazard is the
possible solar-minimum mini-ice age starting soon. I'd prefer
warming.)

John Larkin can be relied on to pick up the silliest denialist propaganda on offer. Sun-spot minimums don't produce ice ages - and don't seem to have had anything to do with the little ice. There was some inept academic speculation along those lines a few years ago, which still gets picked up by denialist web-sites, even though the original papers got torn to shreds in short order.

--
Bill Sloman, Sydney

 

On Saturday, July 2, 2016 at 1:41:57 AM UTC+10, Jim Thompson wrote:

On Fri, 01 Jul 2016 09:40:10 -0400, JW <none@dev.null> wrote:

On Fri, 1 Jul 2016 03:26:14 -0700 (PDT) bill.sloman@ieee.org wrote in
Message id: <5cb1b842-1a5d-41ea-a940-df4e3b680e2b@googlegroups.com>:

On Friday, December 21, 2012 at 12:52:17 PM UTC+11, John Larkin wrote:

A bit late on this one, aren't you?

Sloman is noted for his mental slowness and sloth-appeal >:-}

Sadly, Jim Thompson is even more out of touch with reality.

--
Bill Sloman, Sydney

 

[JW]

On Fri, 01 Jul 2016 07:52:36 -0700 John Larkin
<jjlarkin@highlandtechnology.com> wrote in Message id:
<jl0dnb1e19bgk3icmrfqcv3f88s7sk0s6o@4ax.com>:

On Fri, 01 Jul 2016 09:40:10 -0400, JW <none@dev.null> wrote:

On Fri, 1 Jul 2016 03:26:14 -0700 (PDT) bill.sloman@ieee.org wrote in
Message id: <5cb1b842-1a5d-41ea-a940-df4e3b680e2b@googlegroups.com>:

On Friday, December 21, 2012 at 12:52:17 PM UTC+11, John Larkin wrote:

A bit late on this one, aren't you?

Sloman operates on a different time scale from the rest of us.

A different emotional scale, too.

(And I sense the beginnings of a turnaround on the insane AGW thing.
People are looking at the facts at last: our biggest hazard is the
possible solar-minimum mini-ice age starting soon. I'd prefer
warming.)

I'd prefer warming as well, I have a pool, Damn it!
(in New England still waiting for the first heat wave...)

 

[John Larkin]

On Fri, 01 Jul 2016 13:00:01 -0400, JW <none@dev.null> wrote:

On Fri, 01 Jul 2016 07:52:36 -0700 John Larkin
jjlarkin@highlandtechnology.com> wrote in Message id:
jl0dnb1e19bgk3icmrfqcv3f88s7sk0s6o@4ax.com>:

On Fri, 01 Jul 2016 09:40:10 -0400, JW <none@dev.null> wrote:

On Fri, 1 Jul 2016 03:26:14 -0700 (PDT) bill.sloman@ieee.org wrote in
Message id: <5cb1b842-1a5d-41ea-a940-df4e3b680e2b@googlegroups.com>:

On Friday, December 21, 2012 at 12:52:17 PM UTC+11, John Larkin wrote:

A bit late on this one, aren't you?

Sloman operates on a different time scale from the rest of us.

A different emotional scale, too.

(And I sense the beginnings of a turnaround on the insane AGW thing.
People are looking at the facts at last: our biggest hazard is the
possible solar-minimum mini-ice age starting soon. I'd prefer
warming.)

I'd prefer warming as well, I have a pool, Damn it!
(in New England still waiting for the first heat wave...)

Envision ice fishing in the back yard.


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

On Fri, 01 Jul 2016 09:40:10 -0400, JW <none@dev.null> wrote:

On Fri, 1 Jul 2016 03:26:14 -0700 (PDT) bill.sloman@ieee.org wrote in
Message id: <5cb1b842-1a5d-41ea-a940-df4e3b680e2b@googlegroups.com>:

On Friday, December 21, 2012 at 12:52:17 PM UTC+11, John Larkin wrote:

A bit late on this one, aren't you?

It takes him decades to design an oscillator. Do you think an
knee-jerk should take Slowman less than three and a half years?