Test Equipment Anonymous (TEA) group therapy thread

[neo]

Here my 1GHz story.

1) Got a good deal on four 1152a probes from Neganur. It was about 1 year ago.
2) Started to look for a >1GHz scope
3) Prepared to bank out max. 10K$ for a DSOx 6000A, or a DSOX 4000 something. Hack them of course.
4) Sunday I was at the restaurant with my familiy. BING! Mobile Email Notification about a  Keysight DSO6104L 1GHz Scope from, funny enough, Neganur. 1600€ could not resit. SOLD to ME some minutes later.
https://www.eevblog.com/forum/buysellwanted/fs-(eu)-keysight-dso6104l-1ghz-lxi-scope-(used)/
5) Now I am thinking, do I really need a 1GHz scope?

 

You are here, therefore you of course require a 1 GHz scope. 

[tggzzz]

5) Now I am thinking, do I really need a 1GHz scope?

No, of course you don't. You have been a very silly person, and your best hope is to treat this as a learning experience.

Since most people find that financial loss/gain reinforces lessons, I will help you by buying the scope for EUR500.

[Mr. Scram]

Of course you need a 1 GHz scope. You just haven't decided for which project yet. "Top-down driven purchases" it's called.

[BravoV]

"Top-down Driven Purchases" ....

TDP .... 

[Brumby]

Here my 1GHz story.

1) Got a good deal on four 1152a probes from Neganur. It was about 1 year ago.
2) Started to look for a >1GHz scope
3) Prepared to bank out max. 10K$ for a DSOx 6000A, or a DSOX 4000 something. Hack them of course.
4) Sunday I was at the restaurant with my familiy. BING! Mobile Email Notification about a  Keysight DSO6104L 1GHz Scope from, funny enough, Neganur. 1600€ could not resit. SOLD to ME some minutes later.
https://www.eevblog.com/forum/buysellwanted/fs-(eu)-keysight-dso6104l-1ghz-lxi-scope-(used)/
5) Now I am thinking, do I really need a 1GHz scope?

 

You are here, therefore you of course require a 1 GHz scope. 

Best response.   

[tautech]

Far as i know it's all tubes, but then again thats the first I've heard about spark gap oscillators.

They were common in old TIG welders with HF start.

Gawd awful/good RF generators now mostly banned for the RF interference they created.
All the big brands Miller, Hobart etc once used them.

[Cerebus]

Far as i know it's all tubes, but then again thats the first I've heard about spark gap oscillators.

They were common in old TIG welders with HF start.

Gawd awful/good RF generators now mostly banned for the RF interference they created.
All the big brands Miller, Hobart etc once used them.

Well, what is a welder but one BFO* relaxation oscillator.

*Note: Does not, in this instance, stand for Beat Frequency Oscillator.

[bd139]

Spark gap transmitters were nasty. The bandwidth was incredibly large. Bear in mind they were sending CW which these days has a bandwidth of less than 100Hz, they would piss all over the entire radio spectrum at the fundamental frequency and with the harmonics. This wasn't a big issue back when they were used because they were the only users but that would be being a bad citizen. The output was tuned to some degree but the RF leaked out everywhere.

You can make your own one if you fancy it. Get an AM radio, a car battery and a rasp/file. Tune into any frequency on the AM radio and rub the file across the battery terminals, shorting it and listen to the radio.  I would suggest using a 16/0.2 wire for one half of the circuit so if anything gets welded to the battery it will just burn that wire instead of the battery

Edit: as an efficiency point of view, the Titanic had a spark gap transmitter that could suck 5kW out. You can now, with slightly better tech, even home made, get to the other side of the planet on under 5 watts on a good day.

[Specmaster]

Spark gap transmitters were nasty. The bandwidth was incredibly large. Bear in mind they were sending CW which these days has a bandwidth of less than 100Hz, they would piss all over the entire radio spectrum at the fundamental frequency and with the harmonics. This wasn't a big issue back when they were used because they were the only users but that would be being a bad citizen. The output was tuned to some degree but the RF leaked out everywhere.

You can make your own one if you fancy it. Get an AM radio, a car battery and a rasp/file. Tune into any frequency on the AM radio and rub the file across the battery terminals, shorting it and listen to the radio.  I would suggest using a 16/0.2 wire for one half of the circuit so if anything gets welded to the battery it will just burn that wire instead of the battery

Edit: as an efficiency point of view, the Titanic had a spark gap transmitter that could suck 5kW out. You can now, with slightly better tech, even home made, get to the other side of the planet on under 5 watts on a good day.

May I suggest that you don't use the battery terminals as the contacts to make this rudimentary spark transmitter as hydrogen from the battery is highly explosive and you will cause the battery to explode and cover you you in acid and may even go blind. I have seen this happen before and its not pleasant.

Take large cables from the battery to a point away from the battery fumes and try using the file on the wires.

[bd139]

Good advice. When I did the below I was 12 

We did actually leave the file attached to the battery. It didn't explode, just melted a bit. Was a massive great big thing out of a Land Rover.

[tautech]

Spark gap transmitters were nasty. The bandwidth was incredibly large. Bear in mind they were sending CW which these days has a bandwidth of less than 100Hz, they would piss all over the entire radio spectrum at the fundamental frequency and with the harmonics.

Yep.

I fancied building an online circuit I found for one, it used a 10KV furnace igniter transformer for a spark source and capacitively coupled the spark into a primary then induced the HV into a welding lead.
Scary bloody thing it was, crackling away while throwing a 1/4" spark. Bugger that and it went under the bench !

'er indoors wondered what was happening to the radio ! 
  What, wasn't me dear. 

[bd139]

Ok so it's not just me the other half blames for technical faults

[tautech]

Ok so it's not just me the other half blames for technical faults

Buddy, you need wise up........oh shit dear, that radio must be on the blink !
Give it to me and I'll take to the bench and check it's OK.   

Wipe dust off and insert new batteries......there dear it'll work better now. 

[Specmaster]

Ok so it's not just me the other half blames for technical faults

Buddy, you need wise up........oh shit dear, that radio must be on the blink !
Give it to me and I'll take to the bench and check it's OK.   

Wipe dust off and insert new batteries......there dear it'll work better now. 

I wonder how many times that ploy has worked [emoji23]

[bd139]

Depends how dumb the user is. How many times have you heard "have you tried rebooting it?" 

[tautech]

Ok so it's not just me the other half blames for technical faults

Buddy, you need wise up........oh shit dear, that radio must be on the blink !
Give it to me and I'll take to the bench and check it's OK.   

Wipe dust off and insert new batteries......there dear it'll work better now. 

I wonder how many times that ploy has worked [emoji23]

No problem there.

Before we married.....smart as she was, she used to change the frequently popped fuses in her knackered old B&W TV............until the day she got zapped from charged caps. 
For decades since, anything electrical is MY domain. 
 

[Specmaster]

Ok so it's not just me the other half blames for technical faults

Buddy, you need wise up........oh shit dear, that radio must be on the blink !
Give it to me and I'll take to the bench and check it's OK.   

Wipe dust off and insert new batteries......there dear it'll work better now. 

I wonder how many times that ploy has worked [emoji23]

No problem there.

Before we married.....smart as she was, she used to change the frequently popped fuses in her knackered old B&W TV............until the day she got zapped from charged caps. 
For decades since, anything electrical is MY domain.  [emoji14]
 

Did your wife increase your life insurance by any chance, if so be very careful around electricity. [emoji6]

[mnementh]

(SNIP for brevity's sake)

I figured as old as that beast is, it has to use a spark-gap oscillator... 

I mourned the premature death of Douglas Adams for several months; he was one of the most naturally funny people who ever lived. All the great insight and humor that didn't happen... of course, he would probably respond wryly with something like "Not again..."

Far as i know it's all tubes, but then again thats the first I've heard about spark gap oscillators.

 I assumed it was a joke that went over my head. 

Either that, or my "crusty old dragon" aspect is showing again...

Yes. It looks like there was discussion of various soldering stations and then you really dove into the T12 a few pages later at https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg1368325/#msg1368325. So, I think I'll index the conversation from that point.

Yay! One PoI to start the index.

Yes, that looks like a much better place to start. It avoids the back & forth over MetCal vs Hakko vs JBC vs etc bunk.  Thanks!

In further TEA related news my collection now also include the USN (United States Navy)

So now it is "Next stop NASA!" 

No i didn't buy anything i just discovered my 608C has a navy badge on it.

Makes perfect sense that your " Boat Anchor³ " was ex-Navy...  You should name it "Sparky". (Tube-era slang for the ships wireless Comms Officer)

My Tek 2230 (pause to  ) has VeriSuck cal badges on it; not sure if that's a good thing or a bad thing. But I'm starting to feel like maybe it's time for a divorce after 15+ years...

My ex-NASA 2465 is going to the grave with me though. 

Here my 1GHz story.

1) Got a good deal on four 1152a probes from Neganur. It was about 1 year ago.
2) Started to look for a >1GHz scope
3) Prepared to bank out max. 10K$ for a DSOx 6000A, or a DSOX 4000 something. Hack them of course.
4) Sunday I was at the restaurant with my familiy. BING! Mobile Email Notification about a  Keysight DSO6104L 1GHz Scope from, funny enough, Neganur. Panic attak, cold sweat. 1600€ could not resit. SOLD to ME some minutes later.
https://www.eevblog.com/forum/buysellwanted/fs-(eu)-keysight-dso6104l-1ghz-lxi-scope-(used)/
5) Now I am thinking, do I really need a 1GHz scope?

 

Wash your mouth out with soap! Do it NOW!!! 

Far as i know it's all tubes, but then again thats the first I've heard about spark gap oscillators.

They were common in old TIG welders with HF start.

Gawd awful/good RF generators now mostly banned coveted and hoarded away for the RF interference they created.
All the big brands Miller, Hobart etc once used them.

There, fixed that for you.

Spark gap transmitters were nasty. The bandwidth was incredibly large. Bear in mind they were sending CW which these days has a bandwidth of less than 100Hz, they would piss all over the entire radio spectrum at the fundamental frequency and with the harmonics. This wasn't a big issue back when they were used because they were the only users but that would be being a bad citizen. The output was tuned to some degree but the RF leaked out everywhere.

You can make your own one if you fancy it. Get an AM radio, a car battery and a rasp/file. Tune into any frequency on the AM radio and rub the file across the battery terminals, shorting it and listen to the radio.  I would suggest using a 16/0.2 wire for one half of the circuit so if anything gets welded to the battery it will just burn that wire instead of the battery

Edit: as an efficiency point of view, the Titanic had a spark gap transmitter that could suck 5kW out. You can now, with slightly better tech, even home made, get to the other side of the planet on under 5 watts on a good day.

My first Tesla coil used a spark-gap (recovered from a smashed arc-lamp found in the dump) oscillator; honestly, when running the spark-gap was much more sinister in aspect than the lightning from the anode.

Also... what tangential cyclone did I unleash upon this poor, unsuspecting thread with my offhand comment? 

Spark gap transmitters were nasty. The bandwidth was incredibly large. Bear in mind they were sending CW which these days has a bandwidth of less than 100Hz, they would piss all over the entire radio spectrum at the fundamental frequency and with the harmonics.

Yep.

I fancied building an online circuit I found for one, it used a 10KV furnace igniter transformer for a spark source and capacitively coupled the spark into a primary then induced the HV into a welding lead.
Scary bloody thing it was, crackling away while throwing a 1/4" spark. Bugger that and it went under the bench !

'er indoors wondered what was happening to the radio ! 
  What, wasn't me dear. 

Oh, good lord... I can't think of how many Jacob's Ladders I made from old oil furnace igniter coils as a teenager; I worked in HVAC in the snow belt, so they were readily available for free. Didn't try the spark-gap oscillator with them though... having been bit a few times at work, I had a healthy respect for low-frequency HV.  I guess I should be glad I didn't have ready access to busted microwave ovens (lower voltage transformer, but lethal current capacity) until I was much older and wiser; I probably never would have made it to the "older & wiser" stage. 

Depends how dumb the user is. How many times have you heard "have you tried rebooting it?" 

"Please sir... stop kicking your computer. It won't help, and it angers the pixies inside." 


mnem
Yes, I have worked HellDesk.

[tggzzz]

Spark gap transmitters were nasty. The bandwidth was incredibly large. Bear in mind they were sending CW which these days has a bandwidth of less than 100Hz, they would piss all over the entire radio spectrum at the fundamental frequency and with the harmonics. This wasn't a big issue back when they were used because they were the only users but that would be being a bad citizen. The output was tuned to some degree but the RF leaked out everywhere.

You can make your own one if you fancy it. Get an AM radio, a car battery and a rasp/file. Tune into any frequency on the AM radio and rub the file across the battery terminals, shorting it and listen to the radio.  I would suggest using a 16/0.2 wire for one half of the circuit so if anything gets welded to the battery it will just burn that wire instead of the battery

Edit: as an efficiency point of view, the Titanic had a spark gap transmitter that could suck 5kW out. You can now, with slightly better tech, even home made, get to the other side of the planet on under 5 watts on a good day.

A very easy technique...

• 9V battery
• a PO3000 relay
• relay wired so that N.O. contacts are in series with the coil and battery
• apply power, listen to relay chattering to itself - and to everybody else up to and including the FM band

No, of course I never ever ever did such a thing.

Apparently the QRP distance record is currently 1650 miles using 1microWatt.

[bd139]

I used to make those relay oscillators many years ago as well. Never thought of them as a transmitter. Makes sense really. What I did do was solder two probes to the coil and poked my sister up the arse with them when she was eating dinner instead

That distance record must have been QRSS / WSPR or something like that. I have received on a bit of wire in a tree and a DC receiver someone supposedly kicking out 100mW CW from Italy. That was quite remarkable.

[mnementh]

Spark gap transmitters were nasty. The bandwidth was incredibly large. Bear in mind they were sending CW which these days has a bandwidth of less than 100Hz, they would piss all over the entire radio spectrum at the fundamental frequency and with the harmonics. This wasn't a big issue back when they were used because they were the only users but that would be being a bad citizen. The output was tuned to some degree but the RF leaked out everywhere.

You can make your own one if you fancy it. Get an AM radio, a car battery and a rasp/file. Tune into any frequency on the AM radio and rub the file across the battery terminals, shorting it and listen to the radio.  I would suggest using a 16/0.2 wire for one half of the circuit so if anything gets welded to the battery it will just burn that wire instead of the battery

Edit: as an efficiency point of view, the Titanic had a spark gap transmitter that could suck 5kW out. You can now, with slightly better tech, even home made, get to the other side of the planet on under 5 watts on a good day.

A very easy technique...

• 9V battery
• a PO3000 relay
• relay wired so that N.O. contacts are in series with the coil and battery
• apply power, listen to relay chattering to itself - and to everybody else up to and including the FM band

No, of course I never ever ever did such a thing.

Apparently the QRP distance record is currently 1650 miles using 1microWatt.

This is how a Model T "vibrator" ignition coil worked; timing was provided by the quad point block on the crankshaft. Now we do the same thing with transistor oscillators and coils right on the plug. Ed Huff (who invented the system) was a similar mind to Tesla, though his genius was more concrete and directed towards the infant automobile industry; but it just shows how smart he was that after all these years of evolution, we eventually return to his basic design to simplify and improve reliability.

mnem

[BillB]

May I suggest that you don't use the battery terminals as the contacts to make this rudimentary spark transmitter as hydrogen from the battery is highly explosive and you will cause the battery to explode and cover you you in acid and may even go blind. I have seen this happen before and its not pleasant.

Take large cables from the battery to a point away from the battery fumes and try using the file on the wires.

I'd like to second this!  Please don't do it; an exploding battery also gives off a surprising amount of shrapnel in the form of pointy plastic shards.   

[imidis]

What price would you pull the trigger on this?  /tempted

[Mr. Scram]

What price would you pull the trigger on this?  /tempted

Eight.

[Zucca]

What price would you pull the trigger on this?  /tempted

For mowing the grass: 10$
For the DMM: 5$