Tek Type 516 Restoration

[MED6753]

And here it is. Somewhat dirty. Smells musty after being powered up. It does work, and works well. Was owned by an elderly (much more elderly than me ) gentleman who used it years ago to repair TV's.


As I stated dirty but should clean up. That non-standard bezel will be removed. I have the correct silver bezel. The trace is a nice and sharp blue-green but is not as bright as I would expect. The owner stated that he did replace some HV capacitors. So this needs some investigating. The power switch was originally tied into the scale illum pot but the owner installed a separate toggle switch by the pilot light. I will keep it as is.



The leather carry handle is shot. I will replace it. The covers are in good shape. No painting required. Just a good cleaning.



Interior pix. Dusty but I've seen much worse. And obviously the source of the musty smell.



This Type 516 uses a "turret" type attenuator switch decks which are the same design as old manual TV tuners. First time I've worked with that type and I'm not sure how the vertical compensation is set. I'll soon find out.



Included with the sale was a pile of probes.



The scope will get my usual fare. Cleaning and detailing. PSU re-cap. Repair as necessary and calibration.

[Specmaster]

Nice and neat, also its not too shabby either, a nice addition to the collection.

[MED6753]

The front cleaned up well. Correct bezel installed.



The handle was riveted to the top plate so I had to drill them out. I have a new handle on order which should arrive today. It is the same kind I used on a Type 561B project a few years ago.



The covers also cleaned up well. No painting required.



Next on the agenda is clean the interior and get rid of the musty smell.

[MED6753]

One source of mildew smell was the metal fan filter. Someone had impregnated it with oil and it was black with dirt and mildew. It does NOT need oil to filter properly. Into the kitchen sink with a de-greaser detergent then a cycle in the automatic dishwasher with the caustic dishwasher detergent. It's now clean and odor free.



There's still a slight musty smell after power up but that should be resolved once I clean the chassis and vacuum tubes.

[Reddwarf3r]

Are those staples holding the corners of the filter?
Oil in the filter that's bonkers, how to make a filter harder to clean in one easy step.

[MED6753]

Are those staples holding the corners of the filter?

Yes.

[MED6753]

Today's activity. Cleaning the chassis with an antibacterial cleaner . While I couldn't get every nook and cranny it did pretty much mitigate the musty smell.





This is the new handle that will be mounted on the top plate.



As long as I'm around the audiophools and tube thieves will never get these Bugle Boys. This scope has several of them with labels intact.



Next on the agenda: Drill and mount new handle. PSU capacitors are on order and will be here next week. I noticed one other issue. The alternate mode is pretty much useless at higher sweep speeds. But until the PSU is re-capped and I'm sure is working properly no additional troubleshooting will be done at this time.

[Cubdriver]

Protect those double triodes, Mike!

-Pat

[MED6753]

Those are ECC86/6GM8 which I'm sure the phools lust after. Oddly all the 6DJ8's in this scope are GE branded and USA made so they have almost no appeal to the phools. But it does have a somewhat uncommon ECC82/12AU7 Bugle Boy which could bring big bucks.

[tggzzz]

Those are ECC86/6GM8 which I'm sure the phools lust after. Oddly all the 6DJ8's in this scope are GE branded and USA made so they have almost no appeal to the phools. But it does have a somewhat uncommon ECC82/12AU7 Bugle Boy which could bring big bucks.

Might be tempting to put them up for sale at a truly ludicrous price, just to see how phoolish they are. Would need to protect yourself against complaints/refunds; fleabay collection/cash only might do it.

And if that horse does learn to sing, maybe you would have enough cash to buy 10 scopes

[Zenith]

It's strange how valves which were never thought of as audio valves when they were current, are sought after these days, such as ECC88/6DJ8. Versions with gold plated pins are particularly valued, such as E88CC/6922. E88CC was a special quality version intended for use in computers. It had gold plated pins for less contact problems, not to give it musicality and striking transparency. Most special quality valves were ruggedised. E88CC had cathodes which could tolerate long periods of no cathode current, because those conditions were likely to arise in a computer.

[Cubdriver]

It's strange how valves which were never thought of as audio valves when they were current, are sought after these days, such as ECC88/6DJ8. Versions with gold plated pins are particularly valued, such as E88CC/6922. E88CC was a special quality version intended for use in computers. It had gold plated pins for less contact problems, not to give it musicality and striking transparency. Most special quality valves were ruggedised. E88CC had cathodes which could tolerate long periods of no cathode current, because those conditions were likely to arise in a computer.

Yup. Need a pair of 6922s for a sampling plug-in, and of course the ‘phools have driven the prices into the stratosphere. I’d be willing to bet pretty long odds that if they were part of a blind listening test, they wouldn’t be able to tell a 12AX7 from a 6DJ8 from a 6922.

It always confuses me to hear these guys who have systems that are so close to perfection then say they changed something and 'it opens up the music in ways I never heard before’. WTF? Either your system is so close to perfect that there’s almost no improvement left to be had, or you’re delusional. (Or, for many, I suspect both.)

-Pat

[tggzzz]

It always confuses me to hear these guys who have systems that are so close to perfection then say they changed something and 'it opens up the music in ways I never heard before’. WTF? Either your system is so close to perfect that there’s almost no improvement left to be had, or you’re delusional. (Or, for many, I suspect both.)

-Pat

They will probably be able to distinguish a difference, but won't be able to reliably say which is which or this is better.

Anyone that thinks there is a perfect sound ought to be able to specify where the (single) perfect position for the microphones is.

Ditto deconvolve the sound from their rooms frequency response.

I have a sneaking admiration for anybody that can separate audiophools from their money.

[tggzzz]

One source of mildew smell was the metal fan filter. Someone had impregnated it with oil and it was black with dirt and mildew. It does NOT need oil to filter properly. Into the kitchen sink with a de-greaser detergent then a cycle in the automatic dishwasher with the caustic dishwasher detergent. It's now clean and odor free.

Alternatively, at The Other Place (sic)
https://www.eevblog.com/forum/testgear/ ... msg5120787

[Zenith]

I have a sneaking admiration for anybody that can separate audiophools from their money.

Cryogenicly treated valves, and sonicly competent mains leads are two of my favourites. Speaker cable is another one, with solid silver cable on offer for a high price.

[Cubdriver]

I have a sneaking admiration for anybody that can separate audiophools from their money.

Cryogenicly treated valves, and sonicly competent mains leads are two of my favourites. Speaker cable is another one, with solid silver cable on offer for a high price.

And let’s not forget the speaker cable elevators, hand carved with sharpened obsidian knives one at a time from Tibetan Yak horn by ancient monks who’ve taken a lifelong vow of silence.

The mains cables really make me laugh - hearing some clown go on about how putting the $5k super duper special shielded silver plated gold filled Teflon and silicone insulated IEC cable on his CD player opened up the sound stage and <insert other audiophool drivel here>. Insanity.

-Pat

[MED6753]

One source of mildew smell was the metal fan filter. Someone had impregnated it with oil and it was black with dirt and mildew. It does NOT need oil to filter properly. Into the kitchen sink with a de-greaser detergent then a cycle in the automatic dishwasher with the caustic dishwasher detergent. It's now clean and odor free.

Alternatively, at The Other Place (sic)
https://www.eevblog.com/forum/testgear/ ... msg5120787

.

It seems like the stuff Tek mentions in their manuals is a "dry" lubricant of some sort. The filter in this scope was coated with what appeared to be plain motor oil. The reverse side of the filter housing was totally wet with oil.

[tggzzz]

Gold-plated mains plugs, and sonically superior digital cables amuse me.

Or gold-plated fuses with quantum silver https://www.ebay.co.uk/sch/i.html?_from ... &_osacat=0

But the prices seem far too low. Has there been a price crash due to oversupply, or due to economy of scale?

[mansaxel]

They will probably be able to distinguish a difference, but won't be able to reliably say which is which or this is better.

Anyone that thinks there is a perfect sound ought to be able to specify where the (single) perfect position for the microphones is.

Ditto deconvolve the sound from their rooms frequency response.

I have a sneaking admiration for anybody that can separate audiophools from their money.

From someone who regularly dabbles in live sound, and whose day job is a place that has more controlled acoustic facilities than pretty much any other company in the country save for our siblings at the radio company;

The room. The room, the room, the room. And the speakers. That is where the money and the effort needs to go.

With a possible exception for record players (tape is obsolete and needs to die. Yesterday) the rest of the playback chain is child's play to make very good. For every <kennedy>Haard</kennedy> problem there is caching and buffering, something live sound can not do. The rest is easy from the start. Amplifiers? Solved. Storage? Solved. (you do not need that directional network cable Denon sells) D/A conversion? Potentially hairy, but largely solved. And so on.

[Zenith]

One source of mildew smell was the metal fan filter. Someone had impregnated it with oil and it was black with dirt and mildew. It does NOT need oil to filter properly. Into the kitchen sink with a de-greaser detergent then a cycle in the automatic dishwasher with the caustic dishwasher detergent. It's now clean and odor free.

Alternatively, at The Other Place (sic)
https://www.eevblog.com/forum/testgear/ ... msg5120787

.

It seems like the stuff Tek mentions in their manuals is a "dry" lubricant of some sort. The filter in this scope was coated with what appeared to be plain motor oil. There reverse side of the filter housing was totally wet with oil.

I had a VW Beetle that had an oil bath air filter. The manual said the oil should be replaced every few thousand miles. I used to wash it out and replace it with SAE 30. I doubt Tek intended SAE 30 to go anywhere near their products. I also doubt they mentioned servicing or replacing the filter. It seems like something that might be dealt with by a few good taps outdoors and a vacuum cleaner, unless someone chose to dose it with oil.

Dry lubricants I've come across are graphite loaded, which are black and good for locks, but leave a black and electrically conductive deposit, and PTFE loaded ones, which are good for pot shafts which have become stiff. The best way I've found to use those, is to spray a bit into the cap of a spray can and apply it with a paint brush. That way it goes pretty much where you want it to go and is less wasteful.

[Zenith]

I have a sneaking admiration for anybody that can separate audiophools from their money.

Cryogenicly treated valves, and sonicly competent mains leads are two of my favourites. Speaker cable is another one, with solid silver cable on offer for a high price.

And let’s not forget the speaker cable elevators, hand carved with sharpened obsidian knives one at a time from Tibetan Yak horn by ancient monks who’ve taken a lifelong vow of silence.

The mains cables really make me laugh - hearing some clown go on about how putting the $5k super duper special shielded silver plated gold filled Teflon and silicone insulated IEC cable on his CD player opened up the sound stage and <insert other audiophool drivel here>. Insanity.

-Pat

I can assure you connecting a 20MHz scope to the mains supply via one of these super IEC cables turns it into a 500MHz scope. Of course, you could take the Philistine route and just spend your $5k on a $5k scope, but that would be impossibly vulgar.

It reminds me of wine snobbery. A Chablis, cheeky as you would expect, but not crossing the line into impudence. The nose is good but not entirely complete. Overtones of Autumn fruit and quite pleasing. Not unjustified at £500 a bottle. It could possibly do with another ten years in a sympathetic cellar, but I feel it runs the risk of suffering premature senility.

Bullshit.

[tggzzz]

The room. The room, the room, the room. And the speakers. That is where the money and the effort needs to go.

Yes indeed. In spades. Or just use decent headphones.

As you say, the rest is trivial.

[tggzzz]

I had a VW Beetle that had an oil bath air filter. The manual said the oil should be replaced every few thousand miles. I used to wash it out and replace it with SAE 30.

My Land Rover had one of those, and I used whatever oil was available. My main fear was that if I tipped the Landie on its side the oil would go into the Perkins diesel engine and there would be no way of stopping the engine.

It reminds me of wine snobbery. A Chablis, cheeky as you would expect, but not crossing the line into impudence. The nose is good but not entirely complete. Overtones of Autumn fruit and quite pleasing. Not unjustified at £500 a bottle. It could possibly do with another ten years in a sympathetic cellar, but I feel it runs the risk of suffering premature senility.

I once stayed in a country hotel run by a wine importer. He said the only general truth about wine was that the more you drank, the better it got.

Topical point: the person I was working with found evidence of bedbugs in her bed. The owner's wife plaintively noted that she turned the bed down every day. I can confirm that scratching is contagious.

[Cerebus]

Dry lubricants I've come across are graphite loaded, which are black and good for locks, but leave a black and electrically conductive deposit, and PTFE loaded ones, which are good for pot shafts which have become stiff. The best way I've found to use those, is to spray a bit into the cap of a spray can and apply it with a paint brush. That way it goes pretty much where you want it to go and is less wasteful.

You've missed out the messiest, gets everywhere, dry lubricant that is molybdenum disulphide (metal to metal contact only). You should only use it in someone else's garage/workshop, wearing gloves and overalls that you then throw away before going back to your own house/garage/workshop. If you're in possession of a house proud wife it's best to avoid the stuff entirely.

[Reddwarf3r]

Are those staples holding the corners of the filter?

Yes.

I'm having visions of piles of filter parts being placed on the Sectaries' desk for stapling.