Test Equipment Anonymous (TEA) : Discussion and Group Therapy Thread

[tggzzz]

others here disagree......but I have always really liked the look of those dot LEDs.

No disagreement here. The "font" on my HP5302A frequency meter is very readable.

[Cubdriver]

others here disagree......but I have always really liked the look of those dot LEDs. the 8640b locked to a rubidium standard is my go to sig generator for anything under 500 Mhz.

Of course you would, as do I - they're the closest thing LED-wise to the display of a nixie tube!


-Pat

[mansaxel]

others here disagree......but I have always really liked the look of those dot LEDs. the 8640b locked to a rubidium standard is my go to sig generator for anything under 500 Mhz.

I've got it stacked under my 5245L right now, and there is beauty in both. Through playing with the LF gen in the 8640, I discovered there's some bad contact in the FM slide switch, so I suppose it is inevitable that I open the device up and take a look-see.

[nixiefreqq]

feckin' slide switches........don't get me started!

(its why I gave up on the other wise excellent german made hp pulse generators)

ps and yet for some reason bd is a slide switch fan boy.....he loves the things.

[25 CPS]

New arrival, the -hp- 8640B!

It's been on the wish list basically since I was bit with the TEA bug. And now I own one. A colleague, who already owns one, tipped me off on one that was offered at a low -- for Sweden -- starting price of about 150USD. And it was very local, and pickup only, the latter being very good to scare off remote bidders. And, I sniped it; ending up just below 200 USD. Given the market in Sweden, this is a good price.

Some history:

• It's built in the UK -- supposedly South Queensferry.
• It's got Options 001 and 003, so internal AF oscillator and reverse power protection.
• It's last calibration was 2005, on my birthday, no less. ("It was meant for me!")
• It probably saw use as a non-cal instrument after that, because it's got a sticker saying just as much, "Non calibrated, not for reference work".
• It's got inventory tags from Telenor, the Norwegian Phone Company, but I don't think it was imported from Norway, stickers are in Swedish. Telenor has considerable operations in Sweden, including a subsidiary that maintains 2-way radios and systems like TETRA or older analog trunked radio.

Best part of it all, it works!



Yeah, it's PotatoCAM^tm de luxe, but it is within a few kHz. I've got a 10dB attenuator in line, and have set the 8640B to -30dBm out, and the TinySA reports -37,9dBm.

I'm happy.

Congratulations! That's an excellent score. Especially for the price - I've never seen or heard of one for less than $200 US in any market, not just Sweden. You'll have to keep us posted how it goes as you get a chance to use it more.

[25 CPS]

I went to put some stuff in the recycling bin earlier and I was really surprised to see a little parcel on the front porch. Canada Post has been on strike for almost two weeks and contract talks have broken down very badly, so much so that the government appointed mediator stopped facilitating meetings a couple of days ago. The free/low cost shipping on bits and pieces ordered from China usually get delivered through the post office on this end so I was pretty much accepting that these adapters would get here when they get here sometime after the strike is settled but apparently they used a third party delivery service for these:



1/4 inch tip ring and tip ring sleeve to BNC adapters. I ordered these a while ago before the post office went on strike. The Amber test set and the Strobotac use quarter inch sockets for a number of connections to the outside world plus there's tons of music gear and instruments that use quarter inch TR and TRS connectors as well so I figured that now the need has finally come up, I'd better get a few. Interseries adapters. The amount of interseries adapters you end up accumulating is insane.

[Robert]

New arrival, the -hp- 8640B!

It's been on the wish list basically since I was bit with the TEA bug. And now I own one. A colleague, who already owns one, tipped me off on one that was offered at a low -- for Sweden -- starting price of about 150USD. And it was very local, and pickup only, the latter being very good to scare off remote bidders. And, I sniped it; ending up just below 200 USD. Given the market in Sweden, this is a good price.

Some history:

• It's built in the UK -- supposedly South Queensferry.
• It's got Options 001 and 003, so internal AF oscillator and reverse power protection.
• It's last calibration was 2005, on my birthday, no less. ("It was meant for me!")
• It probably saw use as a non-cal instrument after that, because it's got a sticker saying just as much, "Non calibrated, not for reference work".
• It's got inventory tags from Telenor, the Norwegian Phone Company, but I don't think it was imported from Norway, stickers are in Swedish. Telenor has considerable operations in Sweden, including a subsidiary that maintains 2-way radios and systems like TETRA or older analog trunked radio.

Best part of it all, it works!



Yeah, it's PotatoCAM^tm de luxe, but it is within a few kHz. I've got a 10dB attenuator in line, and have set the 8640B to -30dBm out, and the TinySA reports -37,9dBm.

I'm happy.

Congratulations! That's an excellent score. Especially for the price - I've never seen or heard of one for less than $200 US in any market, not just Sweden. You'll have to keep us posted how it goes as you get a chance to use it more.

I paid £40 for mine a couple of years ago

[25 CPS]

Congratulations! That's an excellent score. Especially for the price - I've never seen or heard of one for less than $200 US in any market, not just Sweden. You'll have to keep us posted how it goes as you get a chance to use it more.

I paid £40 for mine a couple of years ago

I've never encountered a deal like that here. The closest I've come was responding to an advertisement locally for an estate clearout a couple of streets away where the contents of a workshop were being given away for free. There was an 8640B and an 8640A among other things being given away and the guy handling this was totally frazzled and complaining about how a bunch of ham radio operators were behaving. The two 8640s were spoken for by someone who kept jerking him around about when he was going to come and get them. It was only after he said "I have a guy standing right in front of me who's interested in taking them right now" was said on the phone that the clown firmed up on getting in his car to come and get them instead of rescheduling-again. That's the closest I've gotten to getting an 8640B or A, and it's actually the only time I've seen an 8640A in real life. Those don't seem to be nearly as common as the B model.

[25 CPS]

Apparently there's a Tektronix 500 series scope on a scope mobile on display in CTV's lobby. It was completely, totally ignored by the CP-24 hosts though who were looking at an RCA TK-42 camera that's also on display. It's definitely not every day you see a vintage Tek make mainstream media in a live broadcast though in 2024.

[25 CPS]

A whole bunch of LED lights on my truck failed in interesting ways fairly close together. Some went dim, some flickered, and I ended up breaking down and buying four to replace the two above the rear license plate and the front marker lights. That's when I discovered the truck's previous owner must've bought dubious e-commerce website aftermarket garbage. Here's an example of one of these lamps that can't be considered a proper automotive product. This more of a proof of concept or a prototype, at best:

Remember how I left the one dubious LED lamp that was still functioning properly on the truck to see how long it would outlast the others? We now have our answer. It started to very intermittently flicker about a week ago and then pretty much died completely today. I discovered it this evening when I unlocked the truck to put my football gear in before heading off to practice and its side of the license plate was dark. There was some output but it was minimal. You had to look directly into the lamp to see the faintest glow, and this was well after dark too. So, from October 23rd to December 8th, just under seven weeks longer than all the others in that aftermarket LED conversion kit that failed close together.

I'm going to check it out on the bench tomorrow out of curiosity and see if it comes to life on reduced voltage the way the other one did.

[25 CPS]

I'm going to check it out on the bench tomorrow out of curiosity and see if it comes to life on reduced voltage the way the other one did.

Famous last words. Football practice went for two hours instead of one and I was wiped out. Then the weekend was over and the work week began and that was exhausting and frustrating, now it's the next weekend already.

Anyways, Friday brought a totally unexpected pickup. There was a two item lot that looked really cool pretty much one commuter train stop away from the station I parked at so I got in touch with the seller, we agreed, on a price, met in the parking lot at the train station and this is what I got:



This little counter is so cute. It only counts up though so it wouldn't be good for keeping a running total of people in/people out for a total space occupancy count or anything like that. You crank the wing nut to run it up and roll it over 9999 to 0000 to reset it. I'm thinking this is going to become a desk accessory at work to maybe keep track of the number of faults assigned by the coordinators or something like that.



This Sangamo Type F portable watt hour meter was the main item I was interested in though. It'll count up to 20 kWh. It's limited to 5 Amps though so that limits what kind of device testing you can do with it. Higher powered appliances like anything with a heating element would come in over that current limit so I'm not quite sure what the use case for this would've been.



The builder's plate on the back has all the particulars. Interestingly, the frequency box has been both blacked out and gouged out. It's been superseded with the second plate below which states that this meter was given a 60 Hz HEPC Conversion. This meter started out as a 25 Hz unit and was modified for 60 Hz by the Hydro Electric Power Commission sometime after WWII during the frequency standardization project. That's kind of neat.

What I think I might do is connect the workbench lighting through this meter to let it run and see if it counts power consumption while I'm doing something else. It's a couple of incandescent test lamps so it'll be an adequate load to move this meter without exceeding the 5 Amp current limit.

[tautech]

I'm going to check it out on the bench tomorrow out of curiosity and see if it comes to life on reduced voltage the way the other one did.

Famous last words. Football practice went for two hours instead of one and I was wiped out. Then the weekend was over and the work week began and that was exhausting and frustrating, now it's the next weekend already.

Anyways, Friday brought a totally unexpected pickup. There was a two item lot that looked really cool pretty much one commuter train stop away from the station I parked at so I got in touch with the seller, we agreed, on a price, met in the parking lot at the train station and this is what I got:



This little counter is so cute. It only counts up though so it wouldn't be good for keeping a running total of people in/people out for a total space occupancy count or anything like that. You crank the wing nut to run it up and roll it over 9999 to 0000 to reset it. I'm thinking this is going to become a desk accessory at work to maybe keep track of the number of faults assigned by the coordinators or something like that.

Manually operated knitting machines had manual row counters like such.

We can still get these for counting and they range in cost from junk pricing to the better ones many 10's of $.

[tggzzz]

Manually operated knitting machines had manual row counters like such.

My mother has one of those when I was a kid, but I don't remember her using it in anger. I remember playing with it an bit, but it seemed to require careful use to avoid dropping a stitch. ISTR learning to knit during a long boring summer holiday, eventually making a patch maybe 6" square.

She did make a little use of one of the wire mesh frames that you moulded to your body's shape, so that you could adjust dresses.

She also had an internally illuminated "mushroom" used for darning socks. She certainly did that in the 50s.

[Specmaster]

This Sangamo Type F portable watt hour meter was the main item I was interested in though. It'll count up to 20 kWh. It's limited to 5 Amps though so that limits what kind of device testing you can do with it. Higher powered appliances like anything with a heating element would come in over that current limit so I'm not quite sure what the use case for this would've been.



The builder's plate on the back has all the particulars. Interestingly, the frequency box has been both blacked out and gouged out. It's been superseded with the second plate below which states that this meter was given a 60 Hz HEPC Conversion. This meter started out as a 25 Hz unit and was modified for 60 Hz by the Hydro Electric Power Commission sometime after WWII during the frequency standardization project. That's kind of neat.

What I think I might do is connect the workbench lighting through this meter to let it run and see if it counts power consumption while I'm doing something else. It's a couple of incandescent test lamps so it'll be an adequate load to move this meter without exceeding the 5 Amp current limit.

Where would that watt hour meter have been designed / used for then at just 25Hz, I always thought the standard was for either 50 or 60Hz?

[tggzzz]

Where would that watt hour meter have been designed / used for then at just 25Hz, I always thought the standard was for either 50 or 60Hz?

Niagara Falls?
https://en.wikipedia.org/wiki/Utility_f ... Hz_origins

[MED6753]

Where would that watt hour meter have been designed / used for then at just 25Hz, I always thought the standard was for either 50 or 60Hz?

Niagara Falls?
https://en.wikipedia.org/wiki/Utility_f ... Hz_origins

Many US electrified railroads are 25Hz to this day. Old New Haven and Pennsy are examples.

[Zenith]

Some European railways use 16.7Hz.

[mansaxel]

Where would that watt hour meter have been designed / used for then at just 25Hz, I always thought the standard was for either 50 or 60Hz?

Niagara Falls?
https://en.wikipedia.org/wiki/Utility_f ... Hz_origins

Many US electrified railroads are 25Hz to this day. Old New Haven and Pennsy are examples.

Germany, Austria, Switzerland, Sweden and Norway are 15KV 16 ²/₃Hz to this day. Rest of Europe is DC or 50Hz; the DC ones were early, the AC 50Hz late electrifications; now that VFD is a technique mature enough to handle multi-MW (No, Papa Smurf, that's Mega- not MilliWatts! ) drive systems; it is easy to build an engine that

• Runs well from 50Hz, not requiring a RPM-suitable mains frequency
• Through said VFD system, can accept and make use of several different power system standards, sometimes not even requiring a full stop for switchover.

Denmark, squeezed between Sweden and Germany, got its first electrified main line in the late 1980s, when VFD was good enough, so went with 25KV and 50Hz. As Denmark and Sweden were eventually connected by rail via the Öresund bridge,

a number of Swedish locomotives and electric multiple unit passenger trains were rebuilt or ordered new with multi-frequency drive systems to be able to go into Copenhagen Central station. They don't stop as they pass the systems border in Svågertorp on the Swedish side.

[mnementh]

Guess it's time to dust off This Old Chestnut:



This old Chestnut... By mnem

Chestnuts roasting on an open Tek scope;
Jacks and plugs aligned in rows...
Yuletide songs played on tube amplifiers,
And folks warming their hands by the triodes' glow.

Every TEA'er knows... a little extra grid bias and a heated cathode,
Help to make their nixies bright.
EEs and HAMs with their benches all aglow,
Will find it hard to flip that breaker tonight.

They know the carrier's on his way;
He's loaded all kinds of scopes and meters and maybe a 2-way.
And every nerdling's child is going to spy,
To see if a therumin can really make you fly.

And so I'll offer to tune the phase;
on antennas from one to ninety-two...
Although it's been tuned, many times, many ways,
There's no such thing as just right, even when it's Christmas, at two...

Merry Christmas all you maniacs, and may your God go with you!

mnem

[mnementh]

I'm going to check it out on the bench tomorrow out of curiosity and see if it comes to life on reduced voltage the way the other one did.

Famous last words. Football practice went for two hours instead of one and I was wiped out. Then the weekend was over and the work week began and that was exhausting and frustrating, now it's the next weekend already.

Anyways, Friday brought a totally unexpected pickup. There was a two item lot that looked really cool pretty much one commuter train stop away from the station I parked at so I got in touch with the seller, we agreed, on a price, met in the parking lot at the train station and this is what I got:



This little counter is so cute. It only counts up though so it wouldn't be good for keeping a running total of people in/people out for a total space occupancy count or anything like that. You crank the wing nut to run it up and roll it over 9999 to 0000 to reset it. I'm thinking this is going to become a desk accessory at work to maybe keep track of the number of faults assigned by the coordinators or something like that.(SNIP)

You want something bigger, so they can read it from the cheap seats:

mnem
counting down to Christmas with my little grrl...

[AVGresponding]

Got a question from a potential buyer for the Aerialite, about trafo secondaries. They seem to be 220-0, 0-6.3-7.3, with the 0V points connected, and grounded. Am I reading it correctly, are these plausible choob trafo secondary voltages?

[MED6753]

Is that 220V measured from one hot side to the center tap or is it 440V measured across both hots, which makes more sense.

It also sounds like the 6.3V is actually 12.6V measured to each hot. You'll get 6.3V hot to center tap.

[AVGresponding]

It's just what's marked on the trafo. I don't really want to start shoving angry pixies into it, I have variacs, but I don't have a dim bulb tester.

EDIT: To clarify, it seems to have two secondaries, one of 220-0 and one of 0-6.3-7.3, with the 0V terminals connected with an external jumper wire.
EDIT 2: The earth ground is connected to 0V

IMG_20241228_141210933_HDR.jpg

[Zenith]

Got a question from a potential buyer for the Aerialite, about trafo secondaries. They seem to be 220-0, 0-6.3-7.3, with the 0V points connected, and grounded. Am I reading it correctly, are these plausible choob trafo secondary voltages?

They are plausible for a small piece of equipment such as a TV preamp or tuner, or an instrument with just a couple of low power valves. They might use half wave rectification or a solid state bridge. The 7.3 volts is unusual, but they may have used a TV valve designed to have its heater connected in series with other valves, all taking the same current and the whole chain connected to the mains through a dropper resistor. Each valve would have a heater designed to draw 300mA or 100mA depending on the chain, and the voltages across the heaters could be very different.

I'm not clear from your post what the question is, whether you are selling something with this transformer or how the matter arose.

A more usual mains transformer for valve gear would have secondaries of 250-0-250, one or two at 6.3 and possibly a 5V winding for a rectifier, but of course, it would vary a lot depending on the requirements of the equipment.

[AVGresponding]

Got a question from a potential buyer for the Aerialite, about trafo secondaries. They seem to be 220-0, 0-6.3-7.3, with the 0V points connected, and grounded. Am I reading it correctly, are these plausible choob trafo secondary voltages?

They are plausible for a small piece of equipment such as a TV preamp or tuner, or an instrument with just a couple of low power valves. They might use half wave rectification or a solid state bridge. The 7.3 volts is unusual, but they may have used a TV valve designed to have its heater connected in series with other valves, all taking the same current and the whole chain connected to the mains through a dropper resistor. Each valve would have a heater designed to draw 300mA or 100mA depending on the chain, and the voltages across the heaters could be very different.

I'm not clear from your post what the question is, whether you are selling something with this transformer or how the matter arose.

A more usual mains transformer for valve gear would have secondaries of 250-0-250, one or two at 6.3 and possibly a 5V winding for a rectifier, but of course, it would vary a lot depending on the requirements of the equipment.

I'm selling/have been trying to sell an Aerialite TV signal booster.

https://www.ebay.co.uk/itm/326244061071

I keep sending offers that make the price £20 shipped, and I keep getting offers trying to chip away even further. Sorry, nope, the effort involved in packing and shipping it make it not worth my while to entertain such pencil-whipping tactics; I'll take it apart and use the tubes to decorate an AVO meter first!

One potential buyer has actually messaged me a couple of times with questions, one of them being about the trafo secondaries. I was just checking in here to make sure I wasn't making a choob-noob mistake when reading the markings.