Test Equipment Anonymous (TEA) group therapy thread

[tautech]

Reminds my of many years ago being called out to look at a faulty Pressure Pump on a farm. Tuned out to be a dead earwig between the switch contacts. Sunday afternoon emergency call out was lucrative for my 20 minutes on site. Farmer wasn't happy but when are they ever 

Yeah well I thought my water problems were temporally fixed but alas no. 

Boss
tautech, where were you yesterday ?
Sorry boss I had water problems.

Oh, that must have been painful.
Yep it was, the wallet is still hurting.



7m³/hr into 50m head. 

[Mr. Scram]

That's a nice golf trolley.

[med6753]

Yikes! That's a big mo-fo. It has mortgage the farm written all over it. 

[tautech]

Yikes! That's a big mo-fo. It has mortgage the farm written all over it. 

Na, it twasn't too bad, NZD950 plus a 1hr drive each way to collect it. 

Nearly 50kg though and the backend pulsed at little getting it into place. 

[beanflying]

The scrap metal that is your piston pump has to be worth a few $ if you split it into brass and cast first. At least it might cover the fuel 

Just make sure you feed it clean water they are not as forgiving as your old beast even to fine grit.

[med6753]

Yikes! That's a big mo-fo. It has mortgage the farm written all over it. 

Na, it twasn't too bad, NZD950 plus a 1hr drive each way to collect it. 

Nearly 50kg though and the backend pulsed at little getting it into place. 

Ouch, $655 USD is still a good chunk of change but you gotta do it when it comes to a decent water supply. And a 110 pounds dead weight...hernia city. 

[bd139]

Well today's TEA session was spent entirely in fecking Excel writing up calibration curves for a power meter. Has to be done but KIIIIILLLLL MEEEEEEEEE 

[med6753]

Well today's TEA session was spent entirely in fecking Excel writing up calibration curves for a power meter. Has to be done but KIIIIILLLLL MEEEEEEEEE 

Is this for income or "pleasure" ?

[Brumby]

This is the TEA group.  Masochism is endemic, perhaps even mandatory.

[Mr. Scram]

Suddenly the desk is covered in blood. Apparently I've been spreading blood from a nick without noticing.

BLOOD FOR THE TEAMON.

[med6753]

This is the TEA group.  Masochism is endemic, perhaps even mandatory.

Never considered TEA masochistic. Perhaps I have a high tolerance for pain or maybe I'm just an unfeeling old bastard? Yea, it's the later. 

[bd139]

Well today's TEA session was spent entirely in fecking Excel writing up calibration curves for a power meter. Has to be done but KIIIIILLLLL MEEEEEEEEE 

Is this for income or "pleasure" ?

Neither!  ... Masochism it is indeed.

I built a QRP Labs dummy load kit after blowing up several AD8307 front ends on my "low power meter". Unfortunately when they go they go properly leaving scorched PCB so back to basics here and a fat resistor bank goodness good for 20W. I wasn't happy with it totally so I did a couple of mods. I replaced the peak detector diode, a poorly chosen 1n4004 (wtf?!?) with a ST 1N5711 (poor man's Ge diode / HP schottky barrier diode) which increases sensitivity considerably. Also threw the shit plastic Chinese RA BNC in the trash and bunged a nice Amphenol BNC and some RG174 in there. Added some cheap banana sockets and job done. All thrown in a Takachi box which I happened to have lying around from something I never finished.

I could have built this without a kit but honestly I couldn't be fucked with drilling all the holes in the PCB and I had some other stuff coming from then so just spent the $8 on it.

Here it is...



It's getting a nice aluminium mesh lid on it when I can be arsed to do the metalwork, so probably never.

Big surprise though - VSWR is 1.0:1 all the way to 55MHz which is fine for me! Not bad!

Edit: most useful thing I have EVER bought was a very large roll of very stiff 4 conductor ribbon cable for £1 at that hamfest the other day. Amazing stuff for chassis wiring. red/blue strands seen here. Makes like so much easier.

[med6753]

Well, then consider it a job well done, go have a beer, lick your wounds, and quit your bitchin' 

[tautech]

The scrap metal that is your piston pump has to be worth a few $ if you split it into brass and cast first. At least it might cover the fuel 

1/4 tank of diesel is nuthing, one's time is worth much more than that.

Won't be scrapping the ol' girl just yet, as we've spent a bit of $ on her in the last couple of years with new stainless pump rod and input shaft as the gears had worn to knife edges and gotta new conrod pin and bush not even installed yet. 
Good shitty winters day job in the shed to try and resurrect the ol' girl.
In a previous life it did boiler feed and the wet end is entirely of brass, all gorgeous stuff from days gone by. 
Still dunno what caused to bust 'er guts but I have my suspicions.........operator error and NOT mine !

Just make sure you feed it clean water they are not as forgiving as your old beast even to fine grit.

They don't even need grit as the rpm's they run at make them pretty good centrifuges that even separate any fines out of the water into the pump stages but a run into an open line every month or two generally flushes any gathered muck out.
Yep, when I set up the current dam over a good clean spring we shoved a pole in and bolted on a beam back to dry land on which the suction line runs and suspends the foot valve and strainer well off the bottom of the pond.
Screwed some brackets on the poles both ends and have a catwalk too that we can get out on to service the foot valve.

It's worked perfectly and a bit off effort when I set it up has paid off handsomely over the years. 

[beanflying]

A local Brass Foundry 15km from me has made these for a long time (and windmill bits too https://alderdice.com.au/ ) we also used to fit up 50-60 mesh Y strainers on the inlet sides of them. We also used to carry complete inner stacks for them for those who didn't fit a filter $ 

A bit more fancy than an old 20L plastic drum

[tautech]

Yikes! That's a big mo-fo. It has mortgage the farm written all over it. 

Na, it twasn't too bad, NZD950 plus a 1hr drive each way to collect it. 

Nearly 50kg though and the backend pulsed at little getting it into place. 

Ouch, $655 USD is still a good chunk of change but you gotta do it when it comes to a decent water supply. And a 110 pounds dead weight...hernia city. 

Really this one was pretty well priced compared to the little 7 stage single phase one that we had as a backup and bought some 35 yrs back. IIRC it was at least as much $, probably more.
The newbie is a beast by comparison.
Here's the manufacturers webpage for the one I bought, a LVR4-12:
http://www.leogroup.cn/pumps/english/productDetail.aspx?id=107&type=41

The seller was a small fry single brand distributor like myself but specialized in pumps. She was pretty switched on and ran all my piping and static head specs over the phone so to be sure it would do the/my job.
Ya just gotta love specialists, in any field ! 

[tautech]

A local Brass Foundry 15km from me has made these for a long time (and windmill bits too https://alderdice.com.au/ ) we also used to fit up 50-60 mesh Y strainers on the inlet sides of them. We also used to carry complete inner stacks for them for those who didn't fit a filter $ 

A bit more fancy than an old 20L plastic drum

Wouldn't do the job here I don't think Bean, we gotta a bit of surface pond weed and need to get down a bit to get below its roots.
Looks very similar foot valve though that I replaced a couple of months back and unfortunately had to reduce from 2 1/2" to 2" but it doesn't seem to affected performance.

[bd139]

A local Brass Foundry 15km from me has made these for a long time (and windmill bits too https://alderdice.com.au/ ) we also used to fit up 50-60 mesh Y strainers on the inlet sides of them. We also used to carry complete inner stacks for them for those who didn't fit a filter $ 

A bit more fancy than an old 20L plastic drum

That reminds me of this for some reason (contains fake kangaroo balls):

[beanflying]

Well someone had to go dick and balls didn't they  Prepare to be Moderated even if they are not ASCII.

Really this one was pretty well priced compared to the little 7 stage single phase one that we had as a backup and bought some 35 yrs back. IIRC it was at least as much $, probably more.
The newbie is a beast by comparison.
Here's the manufacturers webpage for the one I bought, a LVR4-12:
http://www.leogroup.cn/pumps/english/productDetail.aspx?id=107&type=41

The seller was a small fry single brand distributor like myself but specialized in pumps. She was pretty switched on and ran all my piping and static head specs over the phone so to be sure it would do the/my job.
Ya just gotta love specialists, in any field ! 

I gave you the recommended Grundfos CR 4-120 or SV 4-12 last week when you (not mentioning the likely war ) broke it Clearly a Chinese clone as both the Lowarra (Italian Clone of the Grundfos) and Grundfos will be mid to high $1500's these days. The Clone Wars are real!

[mnementh]

This is the TEA group.  Masochism is endemic, perhaps even mandatory.

Hells YES! This needs to be No 11 of the 10 Laws of TEA!

mnem
Oh, bitseeker...  *Poke Poke*

[mnementh]

Yeah, that's a tough call. Do you tell the unvarnished truth, or replace the switch on GP  to justify being there? Some clients require that I replace the part, no matter what. Some allow me to use my best judgement. Some tell me to err on the side of caution.

If I'm working for myself, I usually tell them the truth and let them decide if they want to pay X amount and probably be good to go, or X plus Y amount to have brand-new installed and not have to wonder how long it will last.

Surprisingly, I often get the latter... and I either put the old part in my stash of emergency spares or in the new part box and hand it to the customer, as they choose.

mnem
"Good. Fast. Cheap. Pick any two."

Would have added $25-40 of Switch to the job and taken another 15 minutes to fit resulting in even more Dairy Farmer (most sooky) unhappiness. The contacts and the switch bodies on these are open to insects of all sorts including spiders of the nasty bitey kind. Normally the spring would smoosh (technical term) them into pulp and the 240V induced spark would bake their bodies away but this earwig had enough exo skeleton to prevent the smooshing.

Yeah, I grew up on a farm. I know EXACTLY what you're talking about; as my grandfather used to say: "You can't make a living selling to people who're scraping the earth for pocket change."

There's a reason I got away from "the life" as quick as I could when I grew up: You don't get up and go to work; you get up and you're surrounded by it. And poverty.

mnem
"You want to make a living, sell what people need. You want to MAKE MONEY, you sell what people WANT." ~ grandmother.

[Brumby]

It just occurred to me...

When removing the attenuators from my 8656B, I only ever used a single spanner on the SMA connectors - but when I put it back together, I needed a second, smaller spanner to tighten up the connection between the short piece of solid coax attached to the rear panel socket and the longer shaped piece that ran around to the output of the attenuators towards the front.  This was an inline connection, just floating in mid-air.

Could it be that this connection was loose all along with the centre conductors not touching, but close enough for a weak capacitive coupling?  If that were the case, then the output being down -116dB would seem pretty reasonable to me.  This explains why I didn't detect anything ... my ability to detect low level signals drops off at around -70dBm to no hope in hell at -80dBm.

Was the fault simply a loose SMA connection that I could have fixed in 5 seconds (quite literally)?

Or is this the trap set by Murphy?

[0culus]

It's entirely possible. SMA is supposed to be torqued (5 in-lbs is a common figure, but it can be more I think), so you should not be able to loosen them with fingers. Perhaps someone monkeyed with it and never tightened them?

[mnementh]

Suddenly the desk is covered in blood. Apparently I've been spreading blood from a nick without noticing.

BLOOD FOR THE TEAMON.

The blood sacrifice has been made... SHE COMES... 

That reminds me of this for some reason (contains fake kangaroo balls):

... oY!!! There she is!   

mnem
Yer fightin' outside of yer weight class there, mate.

[beanflying]

So lets hear some tunes. Bonus points if you run it into a Live Utube stream @Brumby

https://youtu.be/SNbvzsKBxEw