Test Equipment Anonymous

Zenith wrote: ↑Sun Sep 29, 2024 10:07 pm There was a stall selling Tiny SAs and Tiny VNAs. I've toyed with the notion of buying one and it was interesting to see them in the flesh.

I have one of each; you are welcome to play with them.

There are quiet a few variants of the designs, so check which one is currently the best before buying one.

Overall: the SA is a toy compared against my other SAs - in performance, size and price. The VNA is something I don't otherwise have, and is useful, albeit with a slightly annoying UI. One annoyance of mine is that calibrations are lost when the the VNA is turned off.

On National Hamfest.
The "fleamarket" pitches outside were £30 for one table. You are nhave ot allowed a gazebo or awning and if you have an assistant they have to pay another £7.
The R&S Polyscope is an early network analyser. It was a single box, large display, two port solution when the alternative was at least 3 boxes with small display and lots of leads. It brought the network analyser out of the large research lab into small labs and even producton and maintenence.
I've never ben disapponted by NH. At least the fleamarket sellers are a bit more discerning and not the same old sellers dragging the same junk to every rally. It's not a WOW look at all this stuff rally though.

Robert wrote: ↑Mon Sep 30, 2024 7:02 am On National Hamfest.
The "fleamarket" pitches outside were £30 for one table. You are nhave ot allowed a gazebo or awning and if you have an assistant they have to pay another £7.
The R&S Polyscope is an early network analyser. It was a single box, large display, two port solution when the alternative was at least 3 boxes with small display and lots of leads. It brought the network analyser out of the large research lab into small labs and even producton and maintenence.
I've never ben disapponted by NH. At least the fleamarket sellers are a bit more discerning and not the same old sellers dragging the same junk to every rally. It's not a WOW look at all this stuff rally though.

There were about 100 yards of fleamarket tables, about the same as the last time I was there. It didn't take more than about 10 minutes to walk down it and spot anything of interest. Another 100 yards of tables wouldn't have come amiss. It's not as if they are short of space outside. Since the fleamarket opens at 9 am and the hall at 10 am, there's plenty of time to investigate the flea market.

In view of the fact that the weather at this time of year is treacherous, I can't see why gazebos and awnings are a bad thing.

There were a few of the usual small traders inside; the bloke with an enormous number of trays of components in little bags at a quid a pop, Battery Man, and the bloke who smokes black cigarillos. In my estimation it was better two years ago. This time there was more of interest at Telford, where they had a large tent/gazebo for the overflow from the hall, and there were a few who just had tables in the car park.

I didn't mind that much because I combined the rally with something else, long overdue, and which I would have traveled to anyway.

Zenith wrote: ↑Mon Sep 30, 2024 12:30 pm In view of the fact that the weather at this time of year is treacherous, I can't see why gazebos and awnings are a bad thing.

I imagine the insurance company doesn't like the thought of poorly secured gazebos and awnings. The site is a windswept former airfield, whereas Telford's marquee was in a sheltered environment (school buildings, trees)

The probability of rain/drizzle would put me off deciding to have an outside stall until either the last minute, or until the weather forecast had been unchangingly good for several days. That reduces the chance of there being good stuff there.

That may be it. Any outdoor stalls are going to be a dubious proposition from September on. They seem to have gotten away with it at the Chippenham winter rally.

The bacon rolls are always cold or damp at those as well.

Today's project: Extended kitchen prep space.

These are hardwood dorm-size computer desks I picked up a while back; I decided to repurpose them as extended countertop for the kitchen, so moved the keyboard drawers down low and added shelves for stuff I want to use on the new countertops.

A little #1 Poplar, a little drill-press and circular saw time, a little channeling Papa Smurf with the ol' MinWax, and voilips! Kitchen prep stations with storage for... stuff.

mnem

"Old dresser in the bedroom, you're next."

.

.

so........you purposely put the new shelves at different heights just to trigger my OCD........didn't ya'?

"Humans have an instinctual need and preference for balance and order, so we are drawn to symmetrical designs at a subconscious, visceral level. Finding such equilibrium in your home can help you establish an idyllic, calming atmosphere." - stolen from the interwebs

ps I was also gonna' complain to the OP about this post being off topic....but it turns out he would most likely side with you. Curses, foiled again!

I have... things. Things which are odd heights, and yet must be kept. Yea, verily, I did put those shelves at odd heights, thereby to accommodate.

mnem
forsooth; what of mine blenders...?

nixiefreqq wrote: ↑Tue Oct 01, 2024 1:40 am so........you purposely put the new shelves at different heights just to trigger my OCD........didn't ya'?

"Humans have an instinctual need and preference for balance and order, so we are drawn to symmetrical designs at a subconscious, visceral level. Finding such equilibrium in your home can help you establish an idyllic, calming atmosphere." - stolen from the interwebs

ps I was also gonna' complain to the OP about this post being off topic....but it turns out he would most likely side with you. Curses, foiled again!

And yet there is the golden ratio in architecture and many other places, the rule of thirds for photos, etc

Plus "selected randomness" has its own attractions

Zenith wrote: ↑Sun Sep 29, 2024 10:07 pm

I did see a Polyskop shown doing something not very impressive, at the back of one of the stalls for £50. It looked very big and heavy. I'd guess it was some description of spectrum analyser. I'd heard of the name as one of the bits of kit used for setting up the filters in RA17s although that one looked newer. Times have moved on, and what would have been mega impressive in the 1950s is no longer so.

Polyskops were still pretty impressive in the 1980s.

We used to lug the monsters around the State on routine maintenance visits to remote TV transmitter sites.
They were seriously heavy! but as Robert has pointed out, they included everything in one box.
We could have taken a Wiltron or Wavetek sweeper & indeed, sometimes did, when we ran out of Polyskops, but they required a bundle of ancillary equipment, cables, etc, plus the result would be shown on a "itsy-bitsy" Tek 465 non log scaled display.

The Polykop's convenience of use, huge log scaled display & multiple markers made the initial learning curve & enormous size worthwhile.

bd139 wrote: ↑Mon Sep 30, 2024 5:23 pm The bacon rolls are always cold or damp at those as well.

Not like the delicious & messy beef rolls at Perth Hamfest.
To think that people believe that I go there to look at & possibly buy TE & ham crap, & can't discern my true motive!

vk6zgo wrote: ↑Wed Oct 02, 2024 1:03 am

Zenith wrote: ↑Sun Sep 29, 2024 10:07 pm

I did see a Polyskop shown doing something not very impressive, at the back of one of the stalls for £50. It looked very big and heavy. I'd guess it was some description of spectrum analyser. I'd heard of the name as one of the bits of kit used for setting up the filters in RA17s although that one looked newer. Times have moved on, and what would have been mega impressive in the 1950s is no longer so.

Polyskops were still pretty impressive in the 1980s.

We used to lug the monsters around the State on routine maintenance visits to remote TV transmitter sites.
They were seriously heavy! but as Robert has pointed out, they included everything in one box.
We could have taken a Wiltron or Wavetek sweeper & indeed, sometimes did, when we ran out of Polyskops, but they required a bundle of ancillary equipment, cables, etc, plus the result would be shown on a "itsy-bitsy" Tek 465 non log scaled display.

The Polykop's convenience of use, huge log scaled display & multiple markers made the initial learning curve & enormous size worthwhile.

I have a rather rough looking specimen of the breed in my garage. It was given to me a few years ago by a friend who drug it up from his somewhat-less-than-dry basement. I haven't tried to bring it up; it's rather far back in the repair queue.







(please excuse the poor quality iPad photos...)

-Pat

Fascinating. The Polyskop was clearly a remarkable piece of equipment back in the day.

However, on balance, it's far too big and heavy and I'm glad I didn't buy it. To be honest I wasn't even slightly tempted.

Zenith wrote: ↑Wed Oct 02, 2024 10:50 am Fascinating. The Polyskop was clearly a remarkable piece of equipment back in the day.

However, on balance, it's far too big and heavy and I'm glad I didn't buy it. To be honest I wasn't even slightly tempted.

Yes, it is the sort of thing that was a good investment for a corporate body back in the day, but a bit too monstrous for a home lab.
After all, we can use something a tad less convenient that needs a few extra bits, or in many cases, a Spectrum Analyser with a tracking generator & a directional coupler, or a VNA.

That said, I nearly did buy one about 5 Hamfests back, but it was a 75 Ohm one-------a definite "trap for young players"!

vk6zgo wrote: ↑Wed Oct 02, 2024 11:55 pm That said, I nearly did buy one about 5 Hamfests back, but it was a 75 Ohm one-------a definite "trap for young players"!

And not so young players. I bought an HP8601A sweeper a year back. I didn't spot it had the 75 Ohm option. It wouldn't have made much difference because it was only £10. It wouldn't power up, but that turned out to be a mains switch that needed a good dose of switch cleaner. I need a low loss impedance converter, which opens up a world of wonder.

Zenith wrote: ↑Thu Oct 03, 2024 12:54 pm

vk6zgo wrote: ↑Wed Oct 02, 2024 11:55 pm That said, I nearly did buy one about 5 Hamfests back, but it was a 75 Ohm one-------a definite "trap for young players"!

And not so young players. I bought an HP8601A sweeper a year back. I didn't spot it had the 75 Ohm option. It wouldn't have made much difference because it was only £10. It wouldn't power up, but that turned out to be a mains switch that needed a good dose of switch cleaner. I need a low loss impedance converter, which opens up a world of wonder.

If you could tolerate a 5.72dB loss, it isn't difficult to make a pi-pad with 43.2ohm and 86.6ohm resistors.

looked in my junk box and found these.

tggzzz wrote: ↑Thu Oct 03, 2024 1:33 pm

Zenith wrote: ↑Thu Oct 03, 2024 12:54 pm

vk6zgo wrote: ↑Wed Oct 02, 2024 11:55 pm That said, I nearly did buy one about 5 Hamfests back, but it was a 75 Ohm one-------a definite "trap for young players"!

And not so young players. I bought an HP8601A sweeper a year back. I didn't spot it had the 75 Ohm option. It wouldn't have made much difference because it was only £10. It wouldn't power up, but that turned out to be a mains switch that needed a good dose of switch cleaner. I need a low loss impedance converter, which opens up a world of wonder.

If you could tolerate a 5.72dB loss, it isn't difficult to make a pi-pad with 43.2ohm and 86.6ohm resistors.

Thanks It's worth a try. I've just looked on Digikey and they are standard values and I'm putting together an order from them. This has to work from 100kHz to 110MHz so parasitics might be a killer. It might be better done with surface mount parts. I have few little aluminium boxes about 1"x1"x2" which came from Aliexpress and are good for this sort of thing.

Ready made converters are sold on Aliexpress for about £20. I've generally been happy with things I've bought from there, but they didn't seem to have any BNC to BNC parts which is a minor pain.

Just scored a 3478A for a little more than I wanted, but I've had one on the want list for some time. Sold as "uncalibrated" and with a fairly hot PCB around the safety zener for what looks like the 5V regulator for the analog part (LM340-LAZ-5). Suppose a quick measurement will tell whether the regulator is regulating or the zener is forced to stop things. More when I have the unit on the bench.

I've wanted a bench 5,5-digit meter for some time, and also need more reasons to get started with GPIB for real. I finally have a bunch of compatible instruments so it is about time to start.

Weird scopes, take 5.

There's a "Snap-on oscilloscope and snap-on printer" up for sale. Seriously weird colour scheme, and where are the connectors?
https://www.the-saleroom.com/en-gb/auct ... tion-alert

Perhaps this yootoob video (which, naturally, I haven't wasted my time watching) gives a clue: kv12, rpm trig 700, 1,2,3,4,5,6,7,8,

https://www.youtube.com/watch?v=QUb36tkuY48

No, I'm not interested in a "snap on counsellor digital oscilloscope".

A previous generation automotive oscilloscope with features particular tor internal combustion engines. Probably not good for general use, but just the thing if you want to diagnose and tune a 30 year old sports car.

Ok I bought some TE for once. HP 400EL for £50 delivered. Apparently working. Time will tell!

I managed to not buy a 410c today, and also, which was a bit more annoying TBH, failed to bid on an ESAB inverter MMA welder. I've decided I need one, as there are things that turn up and need welding.

bd139 wrote: ↑Mon Oct 07, 2024 11:08 am Ok I bought some TE for once. HP 400EL for £50 delivered. Apparently working. Time will tell!

Cool! These little HP meters are so much fun. I grabbed a couple pictures of my HP 400EL right before I dashed out the door to go to work this afternoon:





Let us know how it goes with yours once it arrives. Fingers crossed nothing gets damaged in shipping.

mansaxel wrote: ↑Mon Oct 07, 2024 6:09 pm I managed to not buy a 410c today, and also, which was a bit more annoying TBH, failed to bid on an ESAB inverter MMA welder. I've decided I need one, as there are things that turn up and need welding.

What made you decided pass up on the 410C?