Test Equipment Anonymous (TEA) group therapy thread

[AVGresponding]

True, it is not all that fast.  Think of the physics a little bit.  The transmission is true direct drive.  That penny-farthing is even a step more hardcore in the cycling world than even a fixxie (fixed gear).  What happens if you attempt hard braking while travelling at top speed? 

You get to choose from a shortlist of new faces at the reconstructive plastic surgeon's.

[mnementh]

mnem
*still shameless*

[med6753]

Is that the Queen and Duke doing a pub crawl? 

[0culus]

Tonight I ran through most of the 519 adjustment procedure. I had noted two problems, namely that there were some odd trace artifacts on 2 ns/cm, specifically the trace was "curling up" on itself on the right side of the sweep. Additionally, the time base adjustment was not even close.

The trace artifacts were solved by adjusting V331, the 4CX250F that is used as the Miller runup tube in the 519 design. I found that not only was the control grid voltage off (this was my doing when I was trying to resolve this problem last month), the plate voltage was set 15V high. After re-adjusting for 155V on the plate and -3.2V on the grid, the curling trace problem disappeared.

I ran through the time base adjustments using my Type 184 as well as my 8664A synthesized signal generator (for adjusting the fastest time base settings). This brought everything into spec more or less.

Next problem to figure out is that it appears there is a dc short between the center conductor and the outer conductor of the rate generator output. The rate generator works fine, of course, but this makes it damned hard to inject a dc bias for say, testing diode reverse recovery times (which is one of the suggested applications!)

[mnementh]

Well hell.     I have AA cells which can't muster that. 

iR measures a nice low 15 mΩ (!!!) same as my 850mAH Eneloop AAAs, and these delivered that capacity at a 500mA load. 

These are the cheap ones off Amazon (Qty 8/US$11 PRIME), plus they're LSD: https://www.amazon.com/EBL-Rechargeable-Batteries-ProCyco-Technology/dp/B00HIW3Q0Y/

mnem
*toddles off to ded*

[mnementh]

Umm... oklay... If I eat this, am I still allowed to like Monterey Jack...?

One of my favorite fall treats was always a little Jack and some toasted everything bagels or crusty baguette with too much butter... a byproduct of growing up on local product Merlots and Sauvignon blends.

mnem
Too many free wine tours... *hic*

The 2 year is my favorite on a sesame seed bagel.  I recommend you try it.
We Canadians are pretty open-minded; you are still allowed to like Monterey Jack, but will you once you have tried this? 

Ehhh...  even though there is such a thing as lasagna I still enjoy pizza (crispy thin crust please, but fuck anchovies to hell with a steamroller for all eternity) and spaghetti with-a meat-a ball-a, so I'm pretty sure I won't stop loving that flavor combination, even if only for the memories of my youth.

mnem
*knocks self unconscious with a anchovy mallet*

[med6753]

Tonight I ran through most of the 519 adjustment procedure. I had noted two problems, namely that there were some odd trace artifacts on 2 ns/cm, specifically the trace was "curling up" on itself on the right side of the sweep. Additionally, the time base adjustment was not even close.

The trace artifacts were solved by adjusting V331, the 4CX250F that is used as the Miller runup tube in the 519 design. I found that not only was the control grid voltage off (this was my doing when I was trying to resolve this problem last month), the plate voltage was set 15V high. After re-adjusting for 155V on the plate and -3.2V on the grid, the curling trace problem disappeared.

I ran through the time base adjustments using my Type 184 as well as my 8664A synthesized signal generator (for adjusting the fastest time base settings). This brought everything into spec more or less.

Next problem to figure out is that it appears there is a dc short between the center conductor and the outer conductor of the rate generator output. The rate generator works fine, of course, but this makes it damned hard to inject a dc bias for say, testing diode reverse recovery times (which is one of the suggested applications!)

Good deal. I wouldn't think that a plate voltage 15V high would have much effect but a maladjusted grid certainly will. Sounds like the tube was being overdriven into distortion.

[0culus]

Tonight I ran through most of the 519 adjustment procedure. I had noted two problems, namely that there were some odd trace artifacts on 2 ns/cm, specifically the trace was "curling up" on itself on the right side of the sweep. Additionally, the time base adjustment was not even close.

The trace artifacts were solved by adjusting V331, the 4CX250F that is used as the Miller runup tube in the 519 design. I found that not only was the control grid voltage off (this was my doing when I was trying to resolve this problem last month), the plate voltage was set 15V high. After re-adjusting for 155V on the plate and -3.2V on the grid, the curling trace problem disappeared.

I ran through the time base adjustments using my Type 184 as well as my 8664A synthesized signal generator (for adjusting the fastest time base settings). This brought everything into spec more or less.

Next problem to figure out is that it appears there is a dc short between the center conductor and the outer conductor of the rate generator output. The rate generator works fine, of course, but this makes it damned hard to inject a dc bias for say, testing diode reverse recovery times (which is one of the suggested applications!)

Good deal. I wouldn't think that a plate voltage 15V high would have much effect but a maladjusted grid certainly will. Sounds like the tube was being overdriven into distortion.

I wouldn't have either, but the grid adjustment did not help until I lowered the plate voltage, at which point the problem went away. 

[med6753]

That is surprising but then again transmitter type tubes tend to be real fussy with their voltage parameters.

[med6753]

Ehhh...  even though there is such a thing as lasagna I still enjoy pizza (crispy thin crust please, but fuck anchovies to hell with a steamroller for all eternity) and spaghetti with-a meat-a ball-a, so I'm pretty sure I won't stop loving that flavor combination, even if only for the memories of my youth.

mnem
*knocks self unconscious with a anchovy mallet*

<------------Loves anchovy pizza. 

[0culus]

That is surprising but then again transmitter type tubes tend to be real fussy with their voltage parameters.

Definitely. The manual does say that it needs to be set to exactly 155V on the plate and -3.2V on the grid.

[mnementh]

Ehhh...  even though there is such a thing as lasagna I still enjoy pizza (crispy thin crust please, but fuck anchovies to hell with a steamroller for all eternity) and spaghetti with-a meat-a ball-a, so I'm pretty sure I won't stop loving that flavor combination, even if only for the memories of my youth.

mnem
*knocks self unconscious with a anchovy mallet*

<------------Loves anchovy pizza. 

You can have all of mine, for the rest of this lifetime and the next. 

mnem
Take anchovies for example... Take them far, far away... I'm begging you, please!!!

[mnementh]

That is surprising but then again transmitter type tubes tend to be real fussy with their voltage parameters.

Definitely. The manual does say that it needs to be set to exactly 155V on the plate and -3.2V on the grid.

FLUKE sez BAMM!!!  And shockingly, now it works.

mnem
 

[0culus]

That is surprising but then again transmitter type tubes tend to be real fussy with their voltage parameters.

Definitely. The manual does say that it needs to be set to exactly 155V on the plate and -3.2V on the grid.

FLUKE sez BAMM!!!  And shockingly, now it works.

mnem
 

I did my best to avoid the "shockingly" part.  After that one time I accidentally grounded 125 V dc through my finger working on the Type 184, I decided once was enough and I need to be more careful.

[Cubdriver]

I also move we also move back to calling “GHz” the “kmc”, or “kilo-megacycle” as the 519 manual does. 

Wouldn't kmc be kilo-millicycles, or just plain Hz?   

(Remember, case is especially important when 'M' is the letter involved...)

-Pat

[vk6zgo]

Perhaps we now "tow toe the line" .....

A picture is worth a thousand three words

We are being a bit picky, though.
Perhaps we need to "reign" ourselves  in!
Or will we leave that to HMTQ?

[0culus]

I also move we also move back to calling “GHz” the “kmc”, or “kilo-megacycle” as the 519 manual does. 

Wouldn't kmc be kilo-millicycles, or just plain Hz?   

(Remember, case is especially important when 'M' is the letter involved...)

-Pat

Long time no see Pat! When you getting on discord???

To answer your question, that’s a good question. You see “kmc” all lower case a lot in old Tek manuals such as the 519 manual.

[BU508A]

Do we have Nixie-fans here?

Dalibor has made an update video about the H-Tube¹ project:




¹Imho the H stands for "Hiroshima"

[vk6zgo]

That is surprising but then again transmitter type tubes tend to be real fussy with their voltage parameters.

In Transmitter service, not so much-----regulated power supplies are more the exeption than the rule with
most tube transmitters.

[bd139]

Heads up for UK folk. It's £1 final value fee weekend!

[Specmaster]

Heads up for UK folk. It's £1 final value fee weekend!

Thanks for the warning, haven't got mine yet 

[bd139]

Heads up for UK folk. It's £1 final value fee weekend!

Thanks for the warning, haven't got mine yet 

Try the promo link here: https://pages.ebay.co.uk/promos/1000444n/

Edit: watch out for the new gotcha though in the T&Cs. It has to sell in the first listing period for the discount to apply. If it is relisted later automatically, no discount!

[tggzzz]

Heads up for UK folk. It's £1 final value fee weekend!

Thanks for the warning, haven't got mine yet 

Try the promo link here: https://pages.ebay.co.uk/promos/1000444n/

Edit: watch out for the new gotcha though in the T&Cs. It has to sell in the first listing period for the discount to apply. If it is relisted later automatically, no discount!

That's not a new T&C.

I hope and presume that delisting an item and  then relisting it again is sufficient to restart that clock. Optionally make a few trivial changes before relisting.

[bd139]

I haven't tried it to be honest. Historically that doesn't always work as a relisting is different to a new listing. It's worth checking. You can get a list of auctions which the discount applies to from the sales overview (bottom - check offers) which is worth doing after you list anything anyway.

My cousin tripped over this a while ago. Sold a MacBook Pro for £1200 on a. £1 listing day. It took 44 days to sell and he got a surprise £120 final fee 

[FransW]

@Tony,

Thanks for the tip on the PM6666 parts mule. I contacted the guy and 3 days later the TE arrived
for the indicated price of 30 euro's. I will post some pictures when I'm done.
BTW, the "mule" wasn't as "muled" as expected. Also the main board is fully functional.
Installed RAM serves the 65, 66 and 69 varieties.
And plenty room for a backlight modification.

The supplier has a nice assortment of used TE. For EU buyers a solution, by avoiding prohibitive US shippng fees:
https://skye-electronics.com/

Thanks,  Frans