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Old 11th December 2013, 12:20 AM   #45541
mikelm is offline mikelm  England
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Wow - solder your speaker leads & line leads both ends ?

You're crazier than me

Last edited by mikelm; 11th December 2013 at 12:23 AM.
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Old 11th December 2013, 12:21 AM   #45542
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Quote:
Originally Posted by jneutron View Post
Are you referring to the TEK 109????

They were sooooo neat.. 250 picosecond 100 volt transitions into 50 ohms

jn
Yes, lost mine in a lab "clean-up" along with my Shibasoku 725.
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Old 11th December 2013, 12:22 AM   #45543
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I have a friend who has been dabbling with manufacturing cables, I doubt he is going to make his fortune from this...

I was at his place one day when he changed a set of interconnect cables for another which were visually identical. For want of a better expression one set sounded a little soft and fuzzy compared to the other. As it happens the more direct sounding pair had the RCA plugs laser welded by a local manufacturing jeweller. The other pair were soldered; identical cables and plugs.

I was simultaneously impressed and depressed that two connections per channel could be so audible.

This was just my observation and the test was sighted, though I didn't know what I was hearing until afterwards.
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Old 11th December 2013, 12:24 AM   #45544
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Originally Posted by simon7000 View Post





The cites more than 90 words ago about the Wiki article.
I meant cites about oxyidation speeded up by running 150uA through a wire.
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Old 11th December 2013, 12:38 AM   #45545
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I don't recall the manual mentioning shipping orientation nor operational orientation. Sounds reasonable though.

The biggest problem I had was the scopes of the day. It was necessary to use a very dark room and allow time for the eyes to adjust to the dark. Scopes of that time also had triggering issues, what a PITA.

jn
My worst give away ever was a 1963 Lumitron sampling scope. One of the greatest tour de forces of discrete design I ever saw. Used every exotic available, tunnel and snap diodes, gold doped transistors, etc. The sampling head was a GR connected hard line with a diode bridge soldered to the center conductor via holes drilled in the outer conductor and the hold capacitor was the grid capacitance of 6CW4's. The trigger circuit was a tunnel diode one shot that hit the sampler via a snap diode edge enhancer. It had a 25psec/div range in 1963.

Barrie Gilbert is the only person I know that knows the story, it came with a reed/charged line pulse generator predating the 109.
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Old 11th December 2013, 12:59 AM   #45546
fas42 is online now fas42  Australia
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Originally Posted by mikelm View Post
Wow - solder your speaker leads & line leads both ends ?

You're crazier than me
And they called Einstein crazy because he said light propagation was a speed limit ... ,

Simple to test - just do it, and see if it makes a difference. I went the fully Monty 30 years ago, and never looked back. Courage, grasshopper ...
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Old 11th December 2013, 01:10 AM   #45547
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Default f.o. darkening -

Ahhh the chance to tell another short story -- I was supposed to be in charge of this new construction of a fiber optics lab.... once apon a time... It seems that x-rays given off during an underground n*****r device test darkens the f.o. data cable and thus attenuates the signal to the above ground signal capturing systems. We needed to calibrate the attenuation or we would never know what the actual signal strength/shape was.... and if possible find a cure for the darkening/attenuation. Hopefully, develop a new f.o. material for that harsh environment. Well, it seems that the French government had spent a fortune designing a scope which -with a hand held probe- could measure waveforms at frequencies in the light spectrum. I got the physicist number and called .... they only made two for their weapons R&D program and no more left to sell to USA. Well our physicist talked to theirs and some money passed hands and Bingo! ... months later we had a newly made light measuring scope in the new F.O. lab. Some great stuff never sees the light of day.
:-)

Thx-RNMarsh
PS - I have a TEK 7S12 with gen and sampling heads (S-52 and S6) that I don't know what to do with. <25ps. Who needs it?

Last edited by RNMarsh; 11th December 2013 at 01:24 AM.
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Old 11th December 2013, 02:10 AM   #45548
fas42 is online now fas42  Australia
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Quote:
Originally Posted by Robert F View Post
I was simultaneously impressed and depressed that two connections per channel could be so audible.

This was just my observation and the test was sighted, though I didn't know what I was hearing until afterwards.
Most of this craziness disappears when the full path has sufficient integrity - allow a weak spot to remain, and the characteristics of that are magnified by all the changes elsewhere. As an example, get some exotic cables which have audible differences - hardwire them and they then become largely indistinguishable ...
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Old 11th December 2013, 04:43 AM   #45549
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If I can find the mercury relays in my stash I'll try that test. How much current?

RE Wirewrap: I must have missed part of the discussion. RCA connectors can be quite marginal. I don't see how the latest fashion with a single point of contact improves the situation, especially wrt: shielding.
10 mA was enough for me to see changes.

The RCA was a follow up on another thread. I had mentioned 1.5 volts dc into a 10K load for an overnighter changed the performance of and RCA cable. That seems to have crossed to this thread. Scott rather than trying the numbers seems to have problems with the issue that there were changes in the connector contact quality. I thought that the actual small contact area with the length of time even though at a low current was obvious. So it is possible for passing dc through your interconnects does change the sound. But I don't think it is due to any of the manure quoted by the advocates of such practices.
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Old 11th December 2013, 06:26 AM   #45550
morinix is offline morinix  United States
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Originally Posted by mikelm View Post
Wow - solder your speaker leads & line leads both ends ?

You're crazier than me
My phono cart has only the contact point of the grid tube socket pin between it and active amplification; Otherwise it is all hard soldrerd. I have had a fire storm of critisim on two forums for doing this. Tim, of EAR fame, was the latest flame thrower. I'm never going back, for this was not a trivial increase in depth.
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Last edited by morinix; 11th December 2013 at 06:29 AM.
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