Test Equipment Anonymous (TEA) group therapy thread

[bitseeker]

Sorry to hear that, mnem. It's a good reminder to check in with folks. Our time here is short.

[bitseeker]

Oh, hey, it's 15% off again on eBay until 11PM PDT. Some restrictions apply.

https://pages.ebay.com/promo/2018/0711/65169.html

[GreyWoolfe]

My cable ISP is all copper. Fiber is the responsibility of the phone company (Verizon). But it's not available here. Too far out in the "boonies" and they won't spend the money to install it.

Copper here also.  I don't live in the boonies but I do live sort of in 'Smallville', pop. ~20K.  We went from 50 Mbps to 100 Mbps with no price increase.  I have a consistant 110 Mbps down and 11 Mbps up.  We won't get fiber here either.  At least, I probably won't be around when it comes.

[Kosmic]

That's a good question which requires voltnuttery. I'll get on that when I get off the time nuttery bandwagon

150 meg would be nice. We're apparently 35th in the world in broadband speeds here in the UK

Get one of these. Accurate and stable enough for 5.5 digits.

Talking about voltage reference, I just received one. Not sure when it was made (from the look of the components inside in the 70s ?) but I really like the front panel.





After couple of hours of warmup I tested the output and it's almost working The voltage is stable but a little off. Some of the switches are really dirty and they need to be cleaned. The nullmeter is working perfectly.

It's going to be a fun restoration project 

[bitseeker]

Neat. I haven't seen an EDC like that before (the usual ones are rackmount proportions). It's reminiscent of a guitar amp of the period, probably because of the knobs.

[med6753]

Nice unit!  I would recommend in addition to the cleaning you plan on doing is a total re-cap before attempting any verification of it's accuracy and stability.

Edit...what's that on the far left? Looks like a shield for a vacuum tube.

[mnementh]

Oh, hey, it's 15% off again on eBay until 11PM PDT. Some restrictions apply.

https://pages.ebay.com/promo/2018/0711/65169.html

Bastards. 

At least I was able to save $25 on the drapes my wife's been bugging me to buy. 


mnem
*Toddling off to ded*

[Specmaster]

That's a good question which requires voltnuttery. I'll get on that when I get off the time nuttery bandwagon

150 meg would be nice. We're apparently 35th in the world in broadband speeds here in the UK

Get one of these. Accurate and stable enough for 5.5 digits.

Talking about voltage reference, I just received one. Not sure when it was made (from the look of the components inside in the 70s ?) but I really like the front panel.





After couple of hours of warmup I tested the output and it's almost working The voltage is stable but a little off. Some of the switches are really dirty and they need to be cleaned. The nullmeter is working perfectly.

It's going to be a fun restoration project 

Wow, good catch and with that you are well and truely on that well greased and slippery slope into voltnuttery ville. Never saw that on Ebay or I'd have been sorely tempted to bid as well [emoji41]

EDIT:
Wow, maybe I might not have bid for this since I have switched on the PC, I can see that it only goes upto 11V and for some instruments voltages of upto 1,000v would be required in order to calibrate them.

[Specmaster]

Nice unit!  I would recommend in addition to the cleaning you plan on doing is a total re-cap before attempting any verification of it's accuracy and stability.

Edit...what's that on the far left? Looks like a shield for a vacuum tube.

I would think that recap is already being planned and a list compiled right now of caps to be ordered for job.

[Zucca]

The 800 is 35W EDP, the 900 is 50W EDP. Mind you, with the SmartHeat setup, 35W is equivalent to 60-70W resistive. The 800 has a plastic housing and cheaper build on the handset; which means of course that it's still like filet mignon compared to the China T-12 clones.

yep, 35W Metcal is perfect and it gives me more soldering time with batteries. Also the magnetic energy saving stand will save me battery juice I hope.

Sorry about your buddy, when God took us something away we should think how much He gave us.

[med6753]

More progress on the Tek 465.

When I stated the other day that channel 1 was fixed that turned out to be premature. I discovered later that channel would not pass any DC. Found that issue. C53 on the input BNC has a tab to bypass the DC around it. That tab was not fully seated into the vertical board. Now it passes DC and have a clean square wave. Other than adjusting all the compensation caps I think channel 1  is now fully repaired.

Channel 2: Still no trace but it looks like I found the cause. The channel 2 trigger is in cut off. See partial schematic. Cannot adjust Ch2 Trigger DC Balance at TP262. It stays at approx -1.4VDC. It should be around -0.2V. If I pull the coax at J262 it stays as is so it's not an issue with the trigger board. It looks like either Q252 or Q262 have taken a dump so I'm replacing both. Tek P/N 151-0221-00 and I'm finding that all cross references (2N4258 and 2N3646) are obsolete. Too bad it doesn't list common 2N3906 as a substitute. Anyway, I found a source of the original Tek parts for $1.29 USD each. Going to get them ordered.

Slowly but surely chipping away at this SOB. 

[Specmaster]

Has that 465 been stored in a damp environment, I don't like the look of those pcb traces.

[med6753]

Has that 465 been stored in a damp environment, I don't like the look of those pcb traces.

Yep, I agree and I came to that same conclusion. The aluminum front panel had corrosion too which I was able to clean up.

[Specmaster]

I bloody hate waiting for parcels to be delivered, at least 3 items arriving today by 3 different means, 1 by TNT, 1 by Hermes and the other by Amazon's own transport and what's the betting that they all turn in close proximity to each other. Hermes say that they will deliver between 11.00 and 15.00, Amazon by 18.00 and TNT just state today. surely today they ought to be able to define a time slot when they expect delivery should be made by??

[tggzzz]

surely today they ought to be able to define a time slot when they expect delivery should be made by??

If they missed that due to, say, traffic, people would be able to complain.

Personally I'd be happy with knowing when they won't materialise, e.g. not before 2pm.

[Specmaster]

surely today they ought to be able to define a time slot when they expect delivery should be made by??

If they missed that due to, say, traffic, people would be able to complain.

Personally I'd be happy with knowing when they won't materialise, e.g. not before 2pm.

Yeah, I'd go with that. Its better then just saying it will be delivered sometime today before 9pm which what Amazon emails normally quotes.

[Kosmic]

Nice unit!  I would recommend in addition to the cleaning you plan on doing is a total re-cap before attempting any verification of it's accuracy and stability.

Edit...what's that on the far left? Looks like a shield for a vacuum tube.

I will definitely check every caps but I'm not sure about completely re-cap. All those caps were super high quality at the time and they might have been hand picked. So I'm planning to check capacitance and ESR first.

About the big metallic part on the left I'm not too sure but yes it look like a vacuum tube. I need to lookup the part #.

[PA0PBZ]

About the big metallic part on the left I'm not too sure but yes it look like a vacuum tube. I need to lookup the part #.

The voltage reference?

[Kosmic]

About the big metallic part on the left I'm not too sure but yes it look like a vacuum tube. I need to lookup the part #.

The voltage reference?

I was looking at the board trying to trace the signal starting from the output and it look like that. That might be the voltage ref 

[med6753]

About the big metallic part on the left I'm not too sure but yes it look like a vacuum tube. I need to lookup the part #.

The voltage reference?

I was looking at the board trying to trace the signal starting from the output and it look like that. That might be the voltage ref 

Pull the shield off then post the numbers that are on the tube.

[bd139]

I bloody hate waiting for parcels to be delivered, at least 3 items arriving today by 3 different means, 1 by TNT, 1 by Hermes and the other by Amazon's own transport and what's the betting that they all turn in close proximity to each other. Hermes say that they will deliver between 11.00 and 15.00, Amazon by 18.00 and TNT just state today. surely today they ought to be able to define a time slot when they expect delivery should be made by??

DPD are the best. 1 hour delivery slot.

I got some shitty SMD practice boards from aliexpress arrive today. Going to try to increase my board filling speed. Considering investing in a roll of 37/63 as well but my word solder has got expensive recently!

[Specmaster]

Well they all turned up at approx 45 minutes intervals. I love this BM867s, it is a nice piece of kit, feels nice and chunky as well as being very solid. It actually feels just like the Fluke 25/27 meters but that backlight is a bit flaky on the left side with some dark patches and my main niggle with it is that the range selector knob is quite small otherwise I'm very happy with it.

[bd139]

It is excellent. Totally happy with mine too. Know what you mean about the backlight but the fluke is wishy washy too. Was a bit worried about the small knob because I have banana fingers but seems fine. Very very solid bit of kit.

I did some comparisons between my Keysight jobby and that this morning on a 2200uF cap and the Keysight took 23 seconds to range to it. BM867 took 7. Smaller caps are instant. Will do a whole series of these tests over the next few days if I get some time.

[Specmaster]

I did some tests against my voltage standard and it is right there alongside my other 4.5 / 5.5 digit meters so I'm very happy. Frequency also agrees although I have yet to test to its limits and the capacitance I have also to check.

Interesting that your Keysight should be so slow considering the huge price difference.

EDIT.
Actually, I have just been informed that the 3478A while it is strictly a 5.5 digit meter, is in reality a 300k count meter so is a 6.5 digit meter that takes the last digit into account and if required adds to the least significant digit, so unless you want to grab a true 6.5 digit meter, I suggest you grab another 3478A. I did think it was a mistake to sell it on, especially seeing as it's so easy to calibrate.

[bd139]

Im happy with the BM867S so far in this space. 500,000 count high res mode gives reasonable relative measurements ie. PLLs, offset voltage on opamps etc. Absolute accuracy is a non issue for me at the current time. Plus the 3478A is a bugger when you’re working on 3.3V referenced stuff (ADC in my case)  as it jumps range just below that.

I’ll bag a 34401A if one comes along for a steal just because but I’m happy with this.

3478A missed three things for me: non GPIB interface, no backlight in my shelf, no safety banana plug ports meaning I could reuse my probes.