Test Equipment Anonymous (TEA) group therapy thread

[Mr. Scram]

Early Japanese transistors are fun. Apparently they had dreadful yields sometimes in the single digit percentages, leading to using them as diodes. They really pulled that one off through sheer determination.

[Specmaster]

looks like we both watched the same documentary then

[Mr. Scram]

looks like we both watched the same documentary then

I even seem to remember we did.

[mnementh]

I learned this sad truth as a youth with a little AM/FM radio that was advertised proudly on the front as having 11 transistors; interestingly the schematic was on a little piece of paper glued to the inside of the device. There were 5 transistors on the schematic, and one was being used as a switch.

After that, I learned to look out for such diversionary tactics.


mnem
*poot!*

[ChrisLX200]

Yep, it's tricky mainly because the cutters are so darn difficult to hold at the angles needed. I do have an attachment I designed and made for the bench grinder (modded since this photo was taken to allow quickly racking the workpiece in X-Y direction), and also another attachment I made out of a spare grinder I attached to the mill. That thing you have complete control over thanks to the mill table, and the swivelling dovetail slide the holder is bolted to. It uses diamond cup wheels to get into awkward corners. So yes, I can do it - but it takes longer to set up for the job than to do it (if you see what I mean)

Ok, I'm good - I did not have an idea of your capabilities and equipment.
So YOU are the EEV tool regrinding service?

LOL, not worth setting up unless I have several to do - which is why the Knipex remain knackered

Finally got around to using the Adonstar to take pics of my Knackered Knipex cutters. They're worse than I thought - don't think I can grind that defect out..

[Specmaster]

Been a lousy couple of weeks on Ebay for me, sold a load of my late Mums Hi-Fi gear 2 weeks ago and still one buyer has not paid for 2 tuners so I'm gonna have to relist it but still I have to pay Ebay their commission even though the buyer has not completed, that sure sucks. To add insult to injury, although I don't need the accuracy as mentioned before, there was a couple of HP 3478A meters I thought I'd take a shot at, both were kind of grubby looking and far from looking at their best but were supposed to be working, one in the UK and the other in the USA.

Both of them went for what I considered to stupid money given their presentation and condition generally and then I ordered a DVI-D lead for the 30" monitor and that went astray and so I'm awaiting another to be sent to me, so all in all a very quiet couple of weeks and bloody boring to boot as I need to clear my bench down of this monitor so I can get back to some radio restoration, but I've nowhere else to stick the monitor 

[KrudyZ]

Yep, it's tricky mainly because the cutters are so darn difficult to hold at the angles needed. I do have an attachment I designed and made for the bench grinder (modded since this photo was taken to allow quickly racking the workpiece in X-Y direction), and also another attachment I made out of a spare grinder I attached to the mill. That thing you have complete control over thanks to the mill table, and the swivelling dovetail slide the holder is bolted to. It uses diamond cup wheels to get into awkward corners. So yes, I can do it - but it takes longer to set up for the job than to do it (if you see what I mean)

Ok, I'm good - I did not have an idea of your capabilities and equipment.
So YOU are the EEV tool regrinding service?

LOL, not worth setting up unless I have several to do - which is why the Knipex remain knackered

Finally got around to using the Adonstar to take pics of my Knackered Knipex cutters. They're worse than I thought - don't think I can grind that defect out..

Use it as a wire stripper...

[bd139]

RIP 

[tggzzz]

Isn't piano wire wonderful.  Great for making scope probe ground spears (provided you work garden and fracture it), or for winch launching gliders. But not for cutting with clippers.

[ChrisLX200]

RIP 

Well I like a challenge No fancy jigs - just hand-held against a fine 8" grind wheel, followed by tarting up with a diamond lap. Doesn't look pretty but at least they do cut now...

[ChrisLX200]

I was looking at that DPS5015 I blew up a while back (with the +/- 50V supply), poked around the discretes and discovered a large Schottky diode which has failed open. Too much to hope it's the only dead component but I;ve ordered some replacements from RS anyway. Really would like to fix this as it is the comms version, my others are standard version.

(removed the diode)

[tautech]

RIP 

Well I like a challenge No fancy jigs - just hand-held against a fine 8" grind wheel, followed by tarting up with a diamond lap. Doesn't look pretty but at least they do cut now...

That's a pretty fine repair. 
Address please as I have a box of cutters you can fix. 

[neo]

Neat. I haven't seen one of those power supplies before. Nice soup cans you've got in there.

Thanks, also theres another one on ebay for 150 shipping included... you know you want to 

There’s a dead one on eBay here for 15 quid. I am tempted but it’s buyer collects from Kidderminster. Would make a nice radio power supply.

The i look at my little switcher which does 16V at 30A and weighs nothing and I suddenly cant be bothered.

I'm the "nothing beats linear" type of guy i guess. 

Well the jokes on me, the price of the second one dropped to $100 and i bought it. So for 250 dollars i got a set of these, a presumed working one and then one with an odd glitch. The first one i got was just too banged up, with it's missing meter, and then it developed this odd short where once it starts it draws more and more current, presumably to an explosive maximum if i let it go too far. Suggestions? I intend to turn the first one into a parts mule but would like to at least know the problem.

[Brumby]

Been a lousy couple of weeks on Ebay for me, sold a load of my late Mums Hi-Fi gear 2 weeks ago and still one buyer has not paid for 2 tuners so I'm gonna have to relist it but still I have to pay Ebay their commission even though the buyer has not completed, that sure sucks.

You shouldn't have to pay any fees/commission for that.  Raise an unpaid item case on the non-paying bidder.  IF they pay, then cool.  If not, the case should close in your favour and you should get a fee credit.

You should wait until the case is closed before relisting - just in case they do pay.

[Specmaster]

I was looking at that DPS5015 I blew up a while back (with the +/- 50V supply), poked around the discretes and discovered a large Schottky diode which has failed open. Too much to hope it's the only dead component but I;ve ordered some replacements from RS anyway. Really would like to fix this as it is the comms version, my others are standard version.

(removed the diode)

Go for it, you could be pleasantly surprised and discover that it is the only part thats failed.

[AF6LJ]

RIP 

Well I like a challenge No fancy jigs - just hand-held against a fine 8" grind wheel, followed by tarting up with a diamond lap. Doesn't look pretty but at least they do cut now...

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=411425;image

RIP 

Well I like a challenge No fancy jigs - just hand-held against a fine 8" grind wheel, followed by tarting up with a diamond lap. Doesn't look pretty but at least they do cut now...

Good work, you had to take quite a bit off those blades, nicely done.

[bd139]

Ah yes aware of that one. unfortunately I’m baby sitting on Sunday. Have firmly booked Dunstable into the calendar though. Nothing will stop that. I’ve actually booked off a day either side of the weekend to absorb any turds that may appear

Edit: I saw a 1502 the other day on eBay. Did consider it.

I’ll have my U1241C with me

Replying to myself and tggzzz...

I did actually get to Kempton in the end. Didn’t buy a lot in the end. Got a copy of the Full license manual from RSGB and some T68-7 toroids and that was it. There was a guy selling a bunch of HP spectrum analysers for £160 a pop (old 180T chassis ones) which we’re interesting but considering I was supposed to be going to Sainsbury’s, I didn’t fancy this situation:

https://youtu.be/11fCIGcCa9c

[Specmaster]

That could have been nasty and you did best to avoid it, have a bit more trouble hiding the SA but toroids are easy to smuggle in 

[tggzzz]

Replying to myself and tggzzz...

I did actually get to Kempton in the end. Didn’t buy a lot in the end. Got a copy of the Full license manual from RSGB and some T68-7 toroids and that was it. There was a guy selling a bunch of HP spectrum analysers for £160 a pop (old 180T chassis ones) which we’re interesting but considering I was supposed to be going to Sainsbury’s, I didn’t fancy this situation:

https://youtu.be/11fCIGcCa9c

I decided against Kempton; I flogged up the M4 too often recently. In the past I haven't been bothered with HP180 SAs, so I'm not sorry I missed them.

Last night I decided to go to the Yeovil ARC on a whim, and then go and look at some scenery. The scenery was obscured, so I gave up on that idea, but not before I got

• Tektronix 115 general-purpose pulse generator with external gating and triggering inputs. The rise and fall time are adjustable down to 10 ns
• Tektronix 2901 time mark generator
• Tektronix 178 Linear IC Test Fixture is a plug-in fixture module for the 577 curve tracer

I had a hard job beating him up to £12 the lot.

There are advantages to provincial meets At the Chippenham one I got a lovely 4 "decade" Dekastat variable resistor for £10; the movement is almost pornographic "Decade" is nominal, since each decade really does go from 0 to 10 (or 11), making the max resistance 121.1ohms.

[Specmaster]

You grabbed yourself a good deal there by the sounds of it. One of these days I'll get to one of these meets and see whats going for myself, in the meantime I'll continue to take my self outside for a swift kicking because I didn't commit to the trip 

[tggzzz]

You grabbed yourself a good deal there by the sounds of it. One of these days I'll get to one of these meets and see whats going for myself, in the meantime I'll continue to take my self outside for a swift kicking because I didn't commit to the trip 

They are very variable. The advantage of Kempton and Harwell is that there can be power, so you might be able to see something working.

FFI about time/location, see http://rsgb.org/main/news/rallies/

[mnementh]

RIP 

Well I like a challenge No fancy jigs - just hand-held against a fine 8" grind wheel, followed by tarting up with a diamond lap. Doesn't look pretty but at least they do cut now...

     

It looks like you cheated... just ground them thinner until the booger went away. I guess I can't blame you; trying to regrind the cutting surface correctly is very hard, especially on shear action cutters like these where having them perfectly parallel is critical.

Yes, this is a case of picking your battles; the conservative action was probably the better choice. 

Replying to myself and tggzzz...

I did actually get to Kempton in the end. Didn’t buy a lot in the end. Got a copy of the Full license manual from RSGB and some T68-7 toroids and that was it. There was a guy selling a bunch of HP spectrum analysers for £160 a pop (old 180T chassis ones) which we’re interesting but considering I was supposed to be going to Sainsbury’s, I didn’t fancy this situation:

https://youtu.be/11fCIGcCa9c

I decided against Kempton; I flogged up the M4 too often recently. In the past I haven't been bothered with HP180 SAs, so I'm not sorry I missed them.

Last night I decided to go to the Yeovil ARC on a whim, and then go and look at some scenery. The scenery was obscured, so I gave up on that idea, but not before I got

• Tektronix 115 general-purpose pulse generator with external gating and triggering inputs. The rise and fall time are adjustable down to 10 ns
• Tektronix 2901 time mark generator
• Tektronix 178 Linear IC Test Fixture is a plug-in fixture module for the 577 curve tracer

I had a hard job beating him up to £12 the lot.

There are advantages to provincial meets At the Chippenham one I got a lovely 4 "decade" Dekastat variable resistor for £10; the movement is almost pornographic "Decade" is nominal, since each decade really does go from 0 to 10 (or 11), making the max resistance 121.1ohms.

Oh yes, good decision; it's obvious you just barely escaped with your gonads intact as it is... 

You grabbed yourself a good deal there by the sounds of it. One of these days I'll get to one of these meets and see whats going for myself, in the meantime I'll continue to take my self outside for a swift kicking because I didn't commit to the trip 

They are very variable. The advantage of Kempton and Harwell is that there can be power, so you might be able to see something working.

FFI about time/location, see http://rsgb.org/main/news/rallies/

Speaking as a long-time flea market veteran, I learned long ago to keep a 4S LiPo and 300W inverter (Used to be a 16V drill pack and a 150W inverter but I upgraded about 10 years ago) and a small DMM in my pocket. I've NEVER regretted it; bargaining from a position of ignorance is always the weaker hand. 


mnem
"Discretion is the better part of Valory... and the rest of 'er ain't too bad, either." ~ my mom

[Specmaster]

Has anyone ever been to the Foxton Radio Rally at all? Just wondering if its any good for bargains at all, its to far away fro me so I might make the trip up the M11 next week if its good.

[ChrisLX200]

...

It looks like you cheated... just ground them thinner until the booger went away. I guess I can't blame you; trying to regrind the cutting surface correctly is very hard, especially on shear action cutters like these where having them perfectly parallel is critical.

Yes, this is a case of picking your battles; the conservative action was probably the better choice. 

LOL well, metal had to come off from somewhere   The Knipex cutters don't appear to come apart which would have been necessary to address the bevelled cutting edge. Still required grinding along the same plane as original otherwise you lose the parallelism of the edges - tongue at right angle needed. Anyway, it was this or the scrap bin.

Maybe I should just buy a pair of these: https://www.amazon.co.uk/dp/B00BL0CCW2/?coliid=IPR94213PMK5M&colid=H3H2EGOSGO8H&psc=0&ref_=lv_ov_lig_dp_it

[bd139]

Has anyone ever been to the Foxton Radio Rally at all? Just wondering if its any good for bargains at all, its to far away fro me so I might make the trip up the M11 next week if its good.

Never been to that one. Repeater groups are usually pretty hardcore so there might be some good stuff there. Then again could be "village hall" material which is all a bit weird.

At Kempton, emptying my brain I saw:

1. Thurlby pulse generator £15
2. 2x HP SA's £160 each
3. 1x dead HP180T scope £15
4. 1x marconi 2019A £195
5. 1x Racal counter £40
6. 3x TTi PL supplies £20-25 each
7. 1x knackered DMM no brand £1
8. 2x Philips LCD based meters £25 each
9. 1x Tek 2215 £60 (bit high!)
10 1x Tek 2225 £95

If I had the cash on me and wasn't supposed to being going to sainsburys I'd have walked out with the 2019A and one of the HP SA's. The SA's aren't great but for the price, I can observe harmonic content, phase noise, IF strips pretty well which is all I really need. Next time!