Haha, as a Ham, you get pretty used to that sort of thing. So do your neighbors. when I first moved into the area, I was very eager to put up a decent mast (Home owner life yo!). Within days a neighbor across the road accused me of causing interference on her TV, was quite stroppy and accusing, saying it was only at night when i was home, never when I was at work. Which is funny, as I hadnt even hung the elements yet, let alone set up my radios. I told her this, and quickly offered to help track down where the noise was coming from. a bit affronted, but accepted the help. scanner in hand, it was quickly tracked down to some "upgraded" led down lights they had installed that week in the kitchen. which of course are only on at night. we are now good friends, she feeds my cat if im away on holidays, and occasionally will bring over some leftovers if she'd had a big family Sunday roast. I'll help out with the big garden jobs like pruning trees (both quite old, love their garden, not quite up to chainsaws and ladders any more tho) and things like setting up a new TV. I wanted to experiment with the lower bands, 40m is about as low as I can go on my property. so spoke to some of my other neighbors and on either side gave me permission to string an element across both of their houses. only for a weekend cos we get very strong winds here n I didnt want it permanent, but yeh, people around here know me as the odd guy with the antenna ;-). its true i guess.
Wow, I didn't expect a light bulb would would be fast enough for voice. I've messed around with using a laser pointer for a similar task, and have seen some really awesome optical WAN network hardware before WiFi was a thing. that used LED's. Pretty cool piece of kit I never knew existed. I've got a bit of British WW2 stuff, unfortunately on almost everything Ive paid more in shipping than the hardware itself (im in Australia, and its not like this stuff is lightweight). very much enjoying seeing some German stuff in action. Thanks Mate!
Thanks for the comment. The light from the bulb is constant. A very advanced prism system provides the modulation. See here for more information: www.la6nca.net/tysk2/lispr/index.htm www.la6nca.net/tysk2/lispr/lispr.pdf
I'm amazed the Germans were able to pull this off with WW2 technology. The biggest problem I see us modulating the light source. They didn't have lasers or LED's that can be switched on and off fast enough and clean enough to carry a voice signal. Incadescent light bulbs just wouldn't be fast enough. How did they do it?
Nice question. Here is an article describing the modulator: www.la6nca.net/tysk2/lispr/lispr.pdf Here is my page showing the modulator: www.la6nca.net/tysk2/lispr80/index.htm
Amazing that they apparently did it with electromechanical vibration of a prism and a very tightly controlled light source. I can't get the first link to open.
If that could have been condensed in size, WW2 fighter or bomber aircraft could have been able to communicate with each other during enforced radio silence. What wouldn't they have given for LEDs etc? Some of the distortion was inescapable due to thermal inertia. The filament of the 'send' lamp didn't heat up nor cool down quickly enough. LEDs would have solved that and power requirements.
So this is not even laser, its just light? And the light pulses are turned into audio? Once again very far reaching technology from the Germans. Super impressive for 1940s technology.
I can imagine what the neighbours say "He's outside again doing weird things"
Great video, thank you :-)
Haha, as a Ham, you get pretty used to that sort of thing. So do your neighbors. when I first moved into the area, I was very eager to put up a decent mast (Home owner life yo!). Within days a neighbor across the road accused me of causing interference on her TV, was quite stroppy and accusing, saying it was only at night when i was home, never when I was at work. Which is funny, as I hadnt even hung the elements yet, let alone set up my radios. I told her this, and quickly offered to help track down where the noise was coming from. a bit affronted, but accepted the help. scanner in hand, it was quickly tracked down to some "upgraded" led down lights they had installed that week in the kitchen. which of course are only on at night. we are now good friends, she feeds my cat if im away on holidays, and occasionally will bring over some leftovers if she'd had a big family Sunday roast. I'll help out with the big garden jobs like pruning trees (both quite old, love their garden, not quite up to chainsaws and ladders any more tho) and things like setting up a new TV.
I wanted to experiment with the lower bands, 40m is about as low as I can go on my property. so spoke to some of my other neighbors and on either side gave me permission to string an element across both of their houses. only for a weekend cos we get very strong winds here n I didnt want it permanent, but yeh, people around here know me as the odd guy with the antenna ;-). its true i guess.
@@arjovenzia Co-operation and consideration. That's excellent :-)
Wow, I didn't expect a light bulb would would be fast enough for voice. I've messed around with using a laser pointer for a similar task, and have seen some really awesome optical WAN network hardware before WiFi was a thing. that used LED's.
Pretty cool piece of kit I never knew existed. I've got a bit of British WW2 stuff, unfortunately on almost everything Ive paid more in shipping than the hardware itself (im in Australia, and its not like this stuff is lightweight). very much enjoying seeing some German stuff in action. Thanks Mate!
Thanks for the comment.
The light from the bulb is constant.
A very advanced prism system provides the modulation.
See here for more information:
www.la6nca.net/tysk2/lispr/index.htm
www.la6nca.net/tysk2/lispr/lispr.pdf
Fascinating apparatus!
Fantastic. I can't help wondering, how many drivers thought that they were caught speeding... Hilsen fra finsk Lappland. 👍😎
So cool ! You can count on the Germany technology.
It's amazing how this old technology latter was used in the end of the century for transmitting data...that is still used today...
;)
Max range may be about 5 km
I will make new attempts at longer distance later.
73 de LA6NCA
Love this! Amazing
Incredible!!
More videos please!!!
Helge Two young electronics engineers in the making :)
Very interesting device... intresting - rebuilt with modern semiconductors, LED and photodiode... And use binocular or teodolite...
German engineering galore! I never heard about sound transmission by light. Did other armies used it too?
Never heard about sound transmission by light? When you make a phone call what do you think travels along the fibre, then?
@@greenman1411 I made it when I was 15 . Plans ware in technical magazine for children . 2 families radios ware little damaged .
@@greenman1411 that s by radiowaves you absolute potato
Very good! thanks for sharing :)
didnt even know they have that at that time... great!
Mye spennende gammelt utstyr!! Fortsett det gode arbeidet!! 73
Did the sound quality improve as it got darker? It looks to be around dusk when the sound quality became good.
Is the light source modulated on a certain frequency, or is the light beam just LF?
I'm amazed the Germans were able to pull this off with WW2 technology. The biggest problem I see us modulating the light source.
They didn't have lasers or LED's that can be switched on and off fast enough and clean enough to carry a voice signal. Incadescent light bulbs just wouldn't be fast enough. How did they do it?
Nice question.
Here is an article describing the modulator:
www.la6nca.net/tysk2/lispr/lispr.pdf
Here is my page showing the modulator:
www.la6nca.net/tysk2/lispr80/index.htm
Amazing that they apparently did it with electromechanical vibration of a prism and a very tightly controlled light source.
I can't get the first link to open.
@@lowercherty First link is a PDF document.
You must have a PDF reader. Download it from the internet.
If that could have been condensed in size, WW2 fighter or bomber aircraft could have been able to communicate with each other during enforced radio silence. What wouldn't they have given for LEDs etc?
Some of the distortion was inescapable due to thermal inertia. The filament of the 'send' lamp didn't heat up nor cool down quickly enough.
LEDs would have solved that and power requirements.
The light bulb was not modulated. The constant light from the bulb was modulated with a complex prism arrangement.
reminds me of the last time I saw my dad
David from Indonesia stand by
Im amazed, how does this works ?
Is it AM modulation or FM modulation ?
AM modulation
En intressant "grej".
norwegians just amazing.
So this is not even laser, its just light? And the light pulses are turned into audio? Once again very far reaching technology from the Germans. Super impressive for 1940s technology.