UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > General Vintage Technology Discussions

Notices

General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc.

Closed Thread
 
Thread Tools
Old 31st Jan 2018, 7:40 pm   #1
CambridgeWorks
Nonode
 
CambridgeWorks's Avatar
 
Join Date: Jun 2010
Location: Spalding, Peterborough, Cambridgeshire, UK.
Posts: 2,851
Default Weird experiments as a beginner in this hobby

Thought I would share some experiences and see if it was not just me that did weird and wonderful things in our early years of this radio/electronic hobby we share and enjoy.
Firstly, in the mid-late 1960s, whilst studying for my RAE I experimented with a spark transmitter. No ordinary one, but a "Concorde Linear" 30W valve audio amp driven by my record player (a Pye transcription type deck and amp from my employer's record sales counter). The output was connected to the primary of a car spark plug ignition coil with a spark plug across the HV secondary. The HT side to my 250 foot longwire, the earth, to earth. Playing my favourite Sandie Shaw record produced a very distorted but recognisable tune EVERYWHERE on my little MW transistor radio! Made a change to Radio Caroline!
Rob
__________________
Apprehension creeping like a tube train up your spine - Cymbaline. Film More soundtrack - Pink Floyd
CambridgeWorks is offline  
Old 31st Jan 2018, 7:49 pm   #2
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Weird experiments as a beginner in this hobby

This sounds a bit like the experiments me and a bunch of schoolfriends did in the 1960s: we had a 'net' using juicy PA amplifiers [with 100V-line outputs] feeding tens-of-Watts into spades rammed into the ground 50-100 feet apart. And sensitive receive-amplifiers [repurposed magnetic-cartridge amps from old record-players].

Best we managed using this was about half a mile. Big problem was AC mains-hum rejection - we learned to reduce the coupling-capacitors in the receive-amps to control this; I series-tuned a couple of old output-transformers to gibe 50/100Hz notches.

[Some of us then went on to use 'ground-carrier transmitters' with PL519 TV output-valves on 60-75KHz and CR100 receivers - best we managed that way was five miles. No mains-hum!]
G6Tanuki is online now  
Old 31st Jan 2018, 9:54 pm   #3
Boom
Retired Dormant Member
 
Join Date: Jan 2007
Location: Westbury, Wiltshire, UK.
Posts: 2,451
Default Re: Weird experiments as a beginner in this hobby

My very first 'transmitter' was sort of by accident when as a child someone taught me how to build a 1kHz multivibrator using a pair of OC44s and I found out that if I connected the output from my record players speaker transformer in series with the supply to it that I could transmit on every frequency from DC to light at the same time as the whistling noises.
Boom is offline  
Old 31st Jan 2018, 9:58 pm   #4
russell_w_b
Dekatron
 
russell_w_b's Avatar
 
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,684
Default Re: Weird experiments as a beginner in this hobby

Quote:
Originally Posted by G6Tanuki View Post
This sounds a bit like the experiments me and a bunch of schoolfriends did in the 1960s: we had a 'net' using juicy PA amplifiers [with 100V-line outputs] feeding tens-of-Watts into spades rammed into the ground 50-100 feet apart.
As part of my work I once did a half-schlumberger ground conductivity test with distances of about a kilometre or so. I had two 100V line public-address amplifiers configured with a bridged output driving 33Hz into a couple of earth stakes via an assortment of cable lengths.

Quote:
Originally Posted by G6Tanuki View Post
est we managed using this was about half a mile. Big problem was AC mains-hum rejection - we learned to reduce the coupling-capacitors in the receive-amps to control this; I series-tuned a couple of old output-transformers to gibe 50/100Hz notches.

[Some of us then went on to use 'ground-carrier transmitters' with PL519 TV output-valves on 60-75KHz and CR100 receivers - best we managed that way was five miles. No mains-hum!]
Interesting. I've often fancied a go at this as I have half-a-mile of DON10 and three acres, so I could get a good electrode spread, as it were. I was thinking of using a Rogers A75 II audio amp (low-Z O/P) but haven't got round to it yet. The further out the electrodes are, the deeper you penetrate.

What was your received audio quality like?
__________________
Regds,

Russell W. B.
G4YLI.
russell_w_b is offline  
Old 1st Feb 2018, 1:25 am   #5
Refugee
Dekatron
 
Refugee's Avatar
 
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,549
Default Re: Weird experiments as a beginner in this hobby

Back in the late 1970s a workmate was listening to the ground with a small battery amplifier.
He came up with various theories as to what he was picking up.
He came round to my place with it so I set about getting something meaningful.
I connected a mains transformer primary to a 25W ILP amplifier module and connected it between mains earth and a spike in the ground in step up mode and fed it with an audio sweep oscillator.
The distinctive signal got about half a mile and by placing the receiver pins at various angles we proved that it was directional.
Refugee is online now  
Old 1st Feb 2018, 12:11 pm   #6
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Weird experiments as a beginner in this hobby

Quote:
Originally Posted by russell_w_b View Post

What was your received audio quality like?
Very much "communications" grade since we were using carbon mics and DLR5 ex-military headsets, along with turning the amp gain up to '11' to get the maximum number of Watts into the ground.
G6Tanuki is online now  
Old 1st Feb 2018, 3:19 pm   #7
The Philpott
Dekatron
 
The Philpott's Avatar
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
Default Re: Weird experiments as a beginner in this hobby

My obsession with weird experiments was probably triggered by a very curious early childhood experience. We lived in the country and it was possible to fall asleep most nights surrounded by a stark but velvety silence, in which the slightest hint of tinnitus or the hum of neurons on tickover became very obvious.

The odd thing about my tinnitus is that it often started well before I had fallen asleep or after I had awoken in the morning (which excludes hypnopompic or hypnagogic hallucination) and it took the form of very rapid, and distinct morse code, at a fairly low volume. I was too young to decode it, and the speed at which it was delivered would have made it really tricky anyway. It went on for minutes at a time. For a while I asumed this was the same for everyone, and it certainly didn't faze me- I just wished Icould understand the dots and dashes!

I don't believe I yet had amalgam fillings at the time, thus I can't fully explain the cause.
The Philpott is offline  
Old 1st Feb 2018, 4:29 pm   #8
CambridgeWorks
Nonode
 
CambridgeWorks's Avatar
 
Join Date: Jun 2010
Location: Spalding, Peterborough, Cambridgeshire, UK.
Posts: 2,851
Default Re: Weird experiments as a beginner in this hobby

About the age of eleven or twelve I became interested in extending the life of U2 type torch batteries. Putting them in the oven for a short time revitalised them slightly.
My dad worked for Lansing Bagnall as a fork lift truck service engineer.
One day, he came home with 4 redundant but working 12v 99Ah batteries. These were huge!
Two were wired in series to provide low voltage lighting for a small shed down the garden.
One day, I had the brainwave to use this supply to charge my 1.5V U2 batteries, one at a time. I decided it was probably safer to use just one 12v battery. This I did. The next thing I recall was a loud noise (cannot remember exact description!) and a sudden pain in my eyes. Yes, it had "exploded", showering my face with all sorts of black debris. I went indoors and mum cleaned me up. Very lucky no serious damage was done to my face, just my shirt or whatever I was wearing. Mum chastised me. "Wait until your father gets home" or similar.
A short while after, this same shed was to hurt me again. This time I had been up a ladder to sit on the roof for some reason. Upon descending, I bravely jumped off from about 2 or 3 rungs up. One foot landing on a piece of scrap wood with a rusty nail sticking out.
My dad was ill in bed and I remember hobbling indoors crying and limping upstairs to show him the wood still attached by the nail right through my shoe to the side of my foot.
When he started to prise it off, I begged him not to because of the pain!
I then had to cycle about 2.5 miles to the doctor for a tetanus jab.
Rob
__________________
Apprehension creeping like a tube train up your spine - Cymbaline. Film More soundtrack - Pink Floyd
CambridgeWorks is offline  
Old 1st Feb 2018, 6:25 pm   #9
The Philpott
Dekatron
 
The Philpott's Avatar
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
Default Re: Weird experiments as a beginner in this hobby

I once linked the audio (white phono) output of a CD player to the video input of a Matsui CRT TV, and the other (red phono) output to my ghetto blaster. With the contrast and brightness at maximum it was fascinating to hear the music, and also 'see' it as groups of white lines of various brightness dashing across the screen from left to right. I couldn't quite believe that it worked as it did. I was unable to replicate it with any other TV set.
The Philpott is offline  
Old 1st Feb 2018, 7:08 pm   #10
Graham G3ZVT
Dekatron
 
Graham G3ZVT's Avatar
 
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,676
Default Re: Weird experiments as a beginner in this hobby

What a fascinating thread! and almost every posting so far has some parallel in my youth.

First though something not mentioned so far.

Modulated Light:
I had a permanent set-up between my bedroom and the guy across the road who had a radio and TV repair shop. Nothing powerful, a torch-bulb with an ORP12 behind it mounted at the focus of a large condenser lens from an enlarger. Half duplex.

My spark transmitter experiments took place while I was still at school, I had a large heavy Bakelite ozone machine, which was simply a big mains transformer with a secondary of several kV. This connected to a pair of terry clips upon which sat a cylinder of waxed paper with a wire mesh on the inside and outside between which sparks jumped producing the ozone, I added an aerial and earth.

I had a 12V battery in my shed with a thin run of bell-wire going up to the shack window, I used to hope for a power cut, and when it eventually came I switched my R107 to DC and continued my "highly important" radio watch.

I briefly did some ground conduction telephone experiments, but I too was more interested in the weird sounds that you could hear.

The multivibrator with the adornment of a couple of tuned circuits in the collectors was a well known practical joke to deploy in the garden of a fellow radio enthusiast.

The Philpott, we could probably talk a long time about tinnitus (I can't remember a time when I didn't "suffer" from it), or indeed what I call "visual tinnitus", the visual auras I experience in the dark, or those associated with migraine, but they will take us way off topic.
__________________
--
Graham.
G3ZVT
Graham G3ZVT is offline  
Old 1st Feb 2018, 7:20 pm   #11
CambridgeWorks
Nonode
 
CambridgeWorks's Avatar
 
Join Date: Jun 2010
Location: Spalding, Peterborough, Cambridgeshire, UK.
Posts: 2,851
Default Re: Weird experiments as a beginner in this hobby

I also made a remote (vhf, 2M AM) radio controlled switch. This was connected to my Philips EL3302 (I think?) cassette tape recorder via the aux input, with "Careful With That Axe Eugene" by Pink Floyd set just at the play position of all the screaming. Turned up the volume full and left it in the front room, paused, waiting for my remote command when gran sat in there after lunch. This she did after a short time. I remotely operated it and then appeared innocently a few seconds later. She didn't bat an eyelid! Probably more stone deaf than a fan of Pink Floyd I imagine!
Rob
__________________
Apprehension creeping like a tube train up your spine - Cymbaline. Film More soundtrack - Pink Floyd
CambridgeWorks is offline  
Old 1st Feb 2018, 8:44 pm   #12
mole42uk
Nonode
 
mole42uk's Avatar
 
Join Date: Aug 2010
Location: Resolfen, Wales; and Bristol, England
Posts: 2,588
Default Re: Weird experiments as a beginner in this hobby

Quote:
Originally Posted by robinshack View Post
I bravely jumped off from about 2 or 3 rungs up. One foot landing on a piece of scrap wood with a rusty nail sticking out.
My dad was ill in bed and I remember hobbling indoors crying and limping upstairs to show him the wood still attached by the nail right through my shoe to the side of my foot.
When he started to prise it off, I begged him not to because of the pain!
I then had to cycle about 2.5 miles to the doctor for a tetanus jab.
Rob
I did something similar running across a field in rural Bedfordshire, maybe about 1963 or so. There was a wrecked pallet and I ran across the obligatory sticky up nail. Straight through my foot and out of the top of my boots, the scar is there to this day. I didn’t tell my parents, I was more worried about the punishment I’d get for the damage to my shoes!
__________________
Richard

Index:
recursive loop: see recursive loop
mole42uk is offline  
Old 1st Feb 2018, 9:39 pm   #13
dseymo1
Retired Dormant Member
 
Join Date: Dec 2007
Location: Shropshire, UK.
Posts: 3,051
Default Re: Weird experiments as a beginner in this hobby

Quote:
Originally Posted by The Philpott View Post
My obsession with weird experiments was probably triggered by a very curious early childhood experience. We lived in the country and it was possible to fall asleep most nights surrounded by a stark but velvety silence, in which the slightest hint of tinnitus or the hum of neurons on tickover became very obvious.

The odd thing about my tinnitus is that it often started well before I had fallen asleep or after I had awoken in the morning (which excludes hypnopompic or hypnagogic hallucination) and it took the form of very rapid, and distinct morse code, at a fairly low volume. I was too young to decode it, and the speed at which it was delivered would have made it really tricky anyway. It went on for minutes at a time. For a while I asumed this was the same for everyone, and it certainly didn't faze me- I just wished Icould understand the dots and dashes!

I don't believe I yet had amalgam fillings at the time, thus I can't fully explain the cause.
Perhaps, like me, you had an iron bedstead which received radio transmissions. In my case it was odd snatches of music and speech at random intervals.
dseymo1 is offline  
Old 1st Feb 2018, 10:39 pm   #14
The Philpott
Dekatron
 
The Philpott's Avatar
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
Default Re: Weird experiments as a beginner in this hobby

..It's..feasible- angle-iron formed the frame and there were the standard links and springs arranged between these angle-irons in a sort of geodetic arrangement that you would expect on an old dismantleable bedstead. When breaking these up and repurposing the angles many years later we found the steel to have nasty hard inclusions in it that laughed at an HSS drill bit- it was really scabby material. The house was a bit damp in places (1800 vintage) and my Dad had Marconi transmitters and receivers stashed away in the junk room downstairs.. i wonder if he was a closet 'ham at the time and was playing downstairs after bedtime!

There was a disused, (damp) blocked up chimney and fireplace next to the bed- can't think how this would be relevant but one never knows. The smoke from the rayburn downstairs went up a parallel chimney and the two merged within the chimneystack.

I always used to know when my metal detector had found a dumped underground bedstead or mattress in the grounds because of the interference generated by the mesh pattern- whenever this interference appeared i didn't bother to dig!
The Philpott is offline  
Old 1st Feb 2018, 11:17 pm   #15
Dai Corner
Hexode
 
Join Date: Oct 2016
Location: Newport, South Wales, UK.
Posts: 278
Default Re: Weird experiments as a beginner in this hobby

I was probably about 6 when I learned that two or three U2s in series lit a bulb brighter than one. It was to puzzle me for several years afterwards that a battery in series with a loudspeaker did not increase the volume.
Dai Corner is offline  
Old 2nd Feb 2018, 2:50 am   #16
Graham G3ZVT
Dekatron
 
Graham G3ZVT's Avatar
 
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,676
Default Re: Weird experiments as a beginner in this hobby

When I was trying to learn Morse code, "Subliminal Learning" was in vogue. This used a speaker under your pillow playing the lesson while you slept.

I has a reel-to-reel battery operated tape recorder, but did not have a time-switch, so I had to improvise one.

My bed-side cabinet had two shelves so I put my clockwork alarm clock on the top shelf and a metal tray on the bottom shelf. Cotton was wound onto the shaft of the alarm winder so that when the alarm went off a metal weight on the other end of the cotton wold be lowered onto the tray and electrical contact made between them.

Believe it or not, this Heath Robinson contraption actually worked occasionally, the only problem being that even though I tried to muffle the sound of the alarm, it invariably woke me up.

That very tape recorder can be seen in the centre of this image.
Attached Thumbnails
Click image for larger version

Name:	g3zvt1.jpg
Views:	159
Size:	48.2 KB
ID:	156573  
__________________
--
Graham.
G3ZVT

Last edited by Graham G3ZVT; 2nd Feb 2018 at 2:58 am.
Graham G3ZVT is offline  
Old 2nd Feb 2018, 3:09 am   #17
Graham G3ZVT
Dekatron
 
Graham G3ZVT's Avatar
 
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,676
Default Re: Weird experiments as a beginner in this hobby

Quote:
Originally Posted by Dai Corner View Post
I was probably about 6 when I learned that two or three U2s in series lit a bulb brighter than one. It was to puzzle me for several years afterwards that a battery in series with a loudspeaker did not increase the volume.
When I was 6 my dad gave me the crystal set that he had made as a boy.
He told me that should move the tuning knob (which incidentally moved a beautifully made variometer) back and forth to get the loudest sound.

The thing was I misunderstood him and believed if I kept doing it the sound would get louder and louder, which of course, in my mind, it did.
__________________
--
Graham.
G3ZVT
Graham G3ZVT is offline  
Old 2nd Feb 2018, 9:02 am   #18
noble kiwi
Pentode
 
Join Date: Jan 2011
Location: Auckland New Zealand
Posts: 175
Default Re: Weird experiments as a beginner in this hobby

My first experiment worthy of comment, occurred at approximately seven years of age.

At the time I sometimes spent time with a cousin, “Digger”, who was into the hobby of constructing radios and thankfully sent me on a lifelong journey. He called his young annoyance “Why Why” for good reason. My question, “how do they make a magnet?" The answer, “they sort of, well, pass electricity through the metal.”

Back home, dad’s basement space, concrete floor, small brass bracket, quite low and accessible ceiling light, batten holder bayonet fitting with lamp removed, big bang, fuse blown, operator down, house lights out. Importantly and luckily, a dry wooden box knocked asunder.

Digger acquired his nickname having been born at the end of the first world war. During the second, he lost his life north of the equator as a pilot officer.

How about during the war, when Ham bands were outlawed and regular power shut downs became necessary and two young guys, a mile apart across a main road were hell bent on making contact. All that vacant copper going the waste !!!
noble kiwi is offline  
Old 2nd Feb 2018, 12:42 pm   #19
The Philpott
Dekatron
 
The Philpott's Avatar
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
Default Re: Weird experiments as a beginner in this hobby

I decided that my alarm clock should have a 'one shot' function, ie sting like a bumblebee and then die as a consequence. It was placed on a muckheap to provide a cushioning effect. My father was using a hammer drill in a 30' x 12' workshop some distance away and heard nothing; he did however feel it. I think i may have overdone it, not for the first time. I do recall the noise of small parts falling on the roof behind me. (on-topic to a certain extent as prototype electronics were involved)
The Philpott is offline  
Old 2nd Feb 2018, 12:57 pm   #20
The Philpott
Dekatron
 
The Philpott's Avatar
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
Default Re: Weird experiments as a beginner in this hobby

Martin G7MRV had an odd (accidental) occurrence which had people foxed for a while:

He had a NiCd pack with displayed a stable voltage, but that voltage would not drop when he tried to demand a current from the battery pack. The connections between the cells had rotted to a dubious looking gunge which seemed to have rather queer semiconductor properties.
Andrew Crosse would have been proud.
The Philpott is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 9:22 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.