Test Equipment Anonymous (TEA) group therapy thread

[bd139]

Need an LCR meter first  . I got 1/3 of the way through that last build and found out my PICkit3 is toast 

[mnementh]

Oh, I'm certain you could find SOMETHING to fill the empty slot between the PFM3000 and your 87...

Something wrong with the programmer, or a wonky cable/ZIF socket board? The (probably clone) programmers are £10-15 on fleaBay.

mnem
*back to the salt mines*

[bd139]

Yeah I'm lurking on a couple more Fluke items 

It blew up. The PICkit3 does that I find. The programmer I have is a clone one because they blow up at about the same rate as the proper ones but cost a lot less to replace. The first one I had was an official one and it lasted about a month before it snuffed it.

[bd139]

Quick PFM3000 review now I've had some time to actually use it. Extremely happy with it. 8.5 digit display, doesn't take up a lot of room, seems to be bang on (2Hz off my DG1022Z at 10MHz), no piddling around - it just counts, 10s gate time is pretty good giving 1Hz resolution at 1Hz update rate (averaged), extremely sensitive - down way below the 10mV it says even at 60MHz. I tried TX'ing on my FT25 next to it with no antenna and it picked up the TX frequency so shielding is pretty crap but it's quite handy that anyway  ... also has a fast measure mode; if you just tap a button when it's off it will pick up the frequency for ~15 seconds and go back to sleep. Display is excellent and due to the positioning it's actually readable on bench



Also finished the 100MHz LO:



Awaiting voltage regulators from RS for tomorrow as it's a bit voltage sensitive still. Have also ordered some supposedly actual 100MHz 5th overtone crystals from aliexpress to see if they are better or not. The current ones are 20MHz and the 5th overtone is 47KHz off 100MHz. It'll still work but it annoys me

[Specmaster]

Yeah, big fan of TTi gear and the air they pack in as well on their bench gear. It just works and meets its specs head on [emoji106]

Sent from my POT-LX1 using Tapatalk

[mnementh]

TEquipment.com has them here in the US for $197. They offer eevBlog members a discount code that's just about enough to cover the sales tax, but hey, better than nothing.

https://www.tequipment.net/TTi/PFM3000/

mnem
*Back unto the breach*

[tggzzz]

The leopard has been on my to do list for decades, and recently I found someone that should do a good job on it. He's an old interesting guy that used to fly microlights, and wants to see my gharial.

Not sure what to do with the leopard; it is too large for its traditional location on the back of the small sofa (plus I don't want daughter's dog to find it too interesting). I'll probably try to invent a way to splat it across the stairway wall.

Definitely too large for that sofa; will have to be splatted across a wall. When considering buying my house, I did note that there is a wall which will be ideal. I prefer to think of that as forward planning; I refuse to consider procrastination.

[worsthorse]

Okay... so "solder the islands" is still "best practice"; but as with most such things, with experience you develop a feel for where you can cheat. 

mnem

yeah, i've never soldered manhattan pads down though i do glue them, mostly because it makes building a little easier and i have this compulsive neatness thing... i use single sided PCB boards mostly and don't build much that goes faster than 100MHz.

and i don't need a handheld frequency counter, as i have three counters that work, but that sure would be handy to have in the tool box. 

[worsthorse]

The leopard has been on my to do list for decades, and recently I found someone that should do a good job on it. He's an old interesting guy that used to fly microlights, and wants to see my gharial.

Not sure what to do with the leopard; it is too large for its traditional location on the back of the small sofa (plus I don't want daughter's dog to find it too interesting). I'll probably try to invent a way to splat it across the stairway wall.

Here in the states, you'd need a plaque on the front door proving you owned that legally and even then you'd probably be fending off attempts to confiscate it on a regular basis.

Have you considered a bigger sofa? 

[bd139]

I rather like the leopard. That's a very classy dead thing. 

[tggzzz]

The leopard has been on my to do list for decades, and recently I found someone that should do a good job on it. He's an old interesting guy that used to fly microlights, and wants to see my gharial.

Not sure what to do with the leopard; it is too large for its traditional location on the back of the small sofa (plus I don't want daughter's dog to find it too interesting). I'll probably try to invent a way to splat it across the stairway wall.

Here in the states, you'd need a plaque on the front door proving you owned that legally and even then you'd probably be fending off attempts to confiscate it on a regular basis.

Have you considered a bigger sofa? 

Taxidermist said that any taxidermist would be prepared to say it was pre 1947, the magic date. I know it is from the mid 30s, and no doubt radiocarbon dating would prove it.

Bigger sofa would mean I'd need longer thighs and a bigger house.

[tggzzz]

I rather like the leopard. That's a very classy dead thing. 

Arguably not the classiest, and I'm not going to post pictures of things my mother owns Daughter has "claimed" one, I've "claimed" another, and taxidermy is currently very fashionable, unlike a couple of decades ago.

Apparently a museum of mice/squirrels doing cute unnatural things was flogged to someone in the states for the cost of a house in the south of England

[bd139]

We’ve got a few unnatural mice somewhere. I’ll dig them out and post a photo when I get into that cupboard next. Doubt they’d pay for a house!

[tggzzz]

Awaiting voltage regulators from RS for tomorrow as it's a bit voltage sensitive still. Have also ordered some supposedly actual 100MHz 5th overtone crystals from aliexpress to see if they are better or not. The current ones are 20MHz and the 5th overtone is 47KHz off 100MHz. It'll still work but it annoys me

Make sure it is a low-noise voltage regulator!

And surely a trimcap would deal with the 47kHz.

[bitseeker]

Quick PFM3000 review now I've had some time to actually use it. Extremely happy with it. 8.5 digit display, doesn't take up a lot of room, seems to be bang on (2Hz off my DG1022Z at 10MHz), no piddling around - it just counts, 10s gate time is pretty good giving 1Hz resolution at 1Hz update rate (averaged), extremely sensitive - down way below the 10mV it says even at 60MHz. I tried TX'ing on my FT25 next to it with no antenna and it picked up the TX frequency so shielding is pretty crap but it's quite handy that anyway  ... also has a fast measure mode; if you just tap a button when it's off it will pick up the frequency for ~15 seconds and go back to sleep. Display is excellent and due to the positioning it's actually readable on bench

That sure is a neat little counter. First time I've seen one. I suppose the minimal to non-existent shielding is a feature for quick mobile measurements. 

[bitseeker]

Definitely too large for that sofa; will have to be splatted across a wall. When considering buying my house, I did note that there is a wall which will be ideal. I prefer to think of that as forward planning; I refuse to consider procrastination.

That's OK. You can contemplate it more later.

[Cubdriver]

The leopard has been on my to do list for decades, and recently I found someone that should do a good job on it. He's an old interesting guy that used to fly microlights, and wants to see my gharial.

Not sure what to do with the leopard; it is too large for its traditional location on the back of the small sofa (plus I don't want daughter's dog to find it too interesting). I'll probably try to invent a way to splat it across the stairway wall.

Here in the states, you'd need a plaque on the front door proving you owned that legally and even then you'd probably be fending off attempts to confiscate it on a regular basis.

Have you considered a bigger sofa? 

Taxidermist said that any taxidermist would be prepared to say it was pre 1947, the magic date. I know it is from the mid 30s, and no doubt radiocarbon dating would prove it.

Bigger sofa would mean I'd need longer thighs and a bigger house.

I can't offer any suggestions as to thigh length, but a bigger house would mean more space for TEA.  Just sayin'...     Lemons, lemonade...

And lord help me I have another Data Precision 3500 DMM coming from everyone's favorite bight.  For $35 + shipping I couldn't resist.  And I'd been doing so well...

-Pat

[0culus]

My most recent TEA was at work, so I have a little bit of equipment in my office rather than have to go to the lab. Besides, some genius blew up the frontend of the (extremely expensive) Keysight scope in the lab...so it's nice to have my own. 

[mnementh]

Something I've found myself contemplating as I sort through various bits of gear and hobby tools and electronics deciding what to keep and what to chunk... for the sake of my survivors and their sanity, I REALLY need to label the stuff as working/not working/fixable/junk... and catalog it all with rough values in my desk journal.  I figure I MIGHT have it all written down by the time they need it.

mnem
Or I could just load up my toolboxes in a UHaul and forget everything else ever existed when we move to Canada... 

[worsthorse]

Something I've found myself contemplating as I sort through various bits of gear and hobby tools and electronics deciding what to keep and what to chunk... for the sake of my survivors and their sanity, I REALLY need to label the stuff as working/not working/fixable/junk... and catalog it all with rough values in my desk journal.  I figure I MIGHT have it all written down by the time they need it.

mnem
Or I could just load up my toolboxes in a UHaul and forget everything else ever existed when we move to Canada... 

Regarding the second option... the garage full of test equipment and ham gear that I spent a zillion hours helping to empty and sort and sell was the result of that strategy. The owner literally packed up everything but the garage, got in his car, and drove away.  It apparently worked okay for him but it was a PITA for everyone else.

About the first option, that's been my primary project for the last three months: sort, document, and inventory the equipment and parts I've acquired over the years, then figure out what needs to go.  I am not so worried about "capturing value" as I am insuring that the detritus of my bad habits will be not be a huge burden on the people around me after I die.   I have seen way too much of that sort of trouble in the last ten years.

[mnementh]

Yeah, but my landlord's a complete dick. 

mnem
Nary a compunction. 

[bd139]

Awaiting voltage regulators from RS for tomorrow as it's a bit voltage sensitive still. Have also ordered some supposedly actual 100MHz 5th overtone crystals from aliexpress to see if they are better or not. The current ones are 20MHz and the 5th overtone is 47KHz off 100MHz. It'll still work but it annoys me

Make sure it is a low-noise voltage regulator!

And surely a trimcap would deal with the 47kHz.

Standard 78L08 with LC pi network after it. Not overly worried about noise from this bit (yet). Mostly concerned with getting it working cost effectively, fixing all the large broken bits and poor bits of design and then optimisation. Call it an "agile" analyser

Trimcap won't do it unfortunately. The trimcap is actually not used for pulling the crystal here but acting as a tank for the larger air wound inductor. The oscillator is actually better described as a crystal disciplined LC oscillator. When you set it up you actually don't install the crystal to start with and replace it with a resistor of approximately the same ESR as the crystal (about 33 ohms here) and a 10nF ceramic cap. It will oscillate without the crystal in then. Trim it to 100MHz then pop the crystal in and it locks to the 5th overtone of the crystal. Unfortunately being a cheap fundamental cut 20MHz crystal, it wasn't cut for the the 5th overtone so it's 47KHz off. Not really a problem as the first IF filter bandwidth is actually nearly 2MHz at 112MHz but I'd rather it was closer because I like seeing more zeroes in the right place. Perhaps there's a time nut inside me somewhere

[tggzzz]

Awaiting voltage regulators from RS for tomorrow as it's a bit voltage sensitive still. Have also ordered some supposedly actual 100MHz 5th overtone crystals from aliexpress to see if they are better or not. The current ones are 20MHz and the 5th overtone is 47KHz off 100MHz. It'll still work but it annoys me

Make sure it is a low-noise voltage regulator!

And surely a trimcap would deal with the 47kHz.

Standard 78L08 with LC pi network after it. Not overly worried about noise from this bit (yet). Mostly concerned with getting it working cost effectively, fixing all the large broken bits and poor bits of design and then optimisation. Call it an "agile" analyser

Trimcap won't do it unfortunately. The trimcap is actually not used for pulling the crystal here but acting as a tank for the larger air wound inductor. The oscillator is actually better described as a crystal disciplined LC oscillator. When you set it up you actually don't install the crystal to start with and replace it with a resistor of approximately the same ESR as the crystal (about 33 ohms here) and a 10nF ceramic cap. It will oscillate without the crystal in then. Trim it to 100MHz then pop the crystal in and it locks to the 5th overtone of the crystal. Unfortunately being a cheap fundamental cut 20MHz crystal, it wasn't cut for the the 5th overtone so it's 47KHz off. Not really a problem as the first IF filter bandwidth is actually nearly 2MHz at 112MHz but I'd rather it was closer because I like seeing more zeroes in the right place. Perhaps there's a time nut inside me somewhere

Ah, OK.

The Tek time mark generators have a standard crystal oscillator, then separate active and passive components for the overtone tank.

As for timenut... clearly if you get an 8 digit anything, then the *nut mentality is being primed ready for explosion.

[bd139]

Yes I prefer that approach myself, particularly after dreaming about crystals all night. This oscillator was more of an experiment to see "can I get 100MHz out of 20MHz crystals forced into an overtone" as it was an interesting design. The objective of the person who did this original design was more to cost cut the original QST article's oscillator which was a far more reputable piece of engineering.



I may build this one yet. Main problem is finding MAV-11's in quantities and quality that isn't a royal buggering. They are a compatible replacement of an old HP MMIC part so I may just look for that once I've worked out what part it is.

On time nuttery I am really after an HP 53131A with OCXO and channel 3 option but being able to get hold of one of them at a reasonable price has proved impossible so far.

[med6753]

I was going to start painting today but that's not going to happen. It's raining, it's cool, and humidity levels are sky high, even inside. Not a good combination for painting. I did get some outside activities completed yesterday like an oil change on one of the cars. So.....guess I'll do some TEA today. 

I still haven't resolved the hum issue on the OL-1. And it is indeed 60Hz hum, not 120Hz ripple from the B+ supply. I've implemented some wiring lead dress changes which have helped. Going to do some more today. I'll show what I've done so far later. I also have a thought as to where the hum may be coming from and an idea to fix it. We'll see.