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

[mansaxel]

Gonna go pop a mess o' "Tektronix Zits", ehhh?

Yah, that.

[Zenith]

It seems a common whinge here is that there are unwashed/unkempt and poorly dressed individuals at radio rallies, but radio hams are Beau Brummel compared to the types you get at model engineering events. Many years ago, there was a chap at Thornbury MEX (Model Engineering eXhibition) where you had to stand aside as he and his smell approached. I'd also say that radio hams tend to be much nicer people than at any other form of car boot sale; I've yet to find one deliberately misdescribing their wares. Yes, you have to rummage, but that's the fun! I found some unused ripper cutters at the Chippenham rally for £1 each - bargain! I've been spoiled by the Newbury rally being only a few miles up the A34, and the McMichael rally not too far away. Didn't even know there was an Andover rally - I'll look out for that one. Any other good ones within an hour's motorcycle ride of Newbury?

It sounds as if you live between Newbury and Reading and like to go by motorbike, which would be a bit limiting should you drop on some 19" gear you couldn't resist. I suggest you look at the rally lists online

https://rsgb.org/main/news/rallies/

https://www.radiorally.co.uk/

You need to look at both, because they don't always agree, and one may miss out details such as the starting time. Then get out a map and maybe look at the reports on here.

I find it's a decision based on the distance, how big it's likely to be and past experience. Big and a lot of interesting things being on offer generally go together, although I have been to small rallies where about the only thing of any interest has been just what I've been looking for. Other factors are whether there's anything interesting to do on the way back, and whether I've been to it before.

The main ones from my point of view are Newbury, Dunstable Downs and FRARS. Telford is pretty good. Rugby is OK and it's a nice drive up the Fosse Way (popular with bikers). MK and Andover have been OK. Hack Green, well the secret nuclear bunker is worth seeing once. W-s-M, Chippenham, Newport, Mendips and Barry are close for me. Bridgend, Sherborne, Exeter, Torbay are not worth the trip. There are one or two others down there which don't seem up to much and probably not worth the trip. Manchester, Blackpool and a host of them in East Anglia may be good, but they are just too far.

[tggzzz]

The main ones from my point of view are Newbury, Dunstable Downs and FRARS. Telford is pretty good. Rugby is OK and it's a nice drive up the Fosse Way (popular with bikers).

Yup.

Good weather and having found an interesting precioussss previously always help.

MK and Andover have been OK.

Never been, and MK would need to be good for the trek

Hack Green, well the secret nuclear bunker is worth seeing once. W-s-M, Chippenham, Newport, Mendips and Barry are close for me. Bridgend, Sherborne, Exeter, Torbay are not worth the trip. There are one or two others down there which don't seem up to much and probably not worth the trip. Manchester, Blackpool and a host of them in East Anglia may be good, but they are just too far.

Agreed, except I like Sherborne partly because of the town, and the only thing I like about Barry is the view towards Devon.

I'll add Winkleigh (Mid Devon) and Sparkford aren't on my "go again" list.

[EC8010]

It sounds as if you live between Newbury and Reading and like to go by motorbike, which would be a bit limiting should you drop on some 19" gear you couldn't resist.

You'd be amazed at what you can get on the back of a bike with three bungies (and I have four). I brought a (small) power hacksaw back a few months ago. I'll see if I feel enthusiastic at oh-God-o'clock tomorrow, so if you see someone staggering around clutching a tank bag, it could well be me.

[tggzzz]

It seems a common whinge here is that there are unwashed/unkempt and poorly dressed individuals at radio rallies, but radio hams are Beau Brummel compared to the types you get at model engineering events. Many years ago, there was a chap at Thornbury MEX (Model Engineering eXhibition) where you had to stand aside as he and his smell approached. I'd also say that radio hams tend to be much nicer people than at any other form of car boot sale; I've yet to find one deliberately misdescribing their wares. Yes, you have to rummage, but that's the fun! I found some unused ripper cutters at the Chippenham rally for £1 each - bargain! I've been spoiled by the Newbury rally being only a few miles up the A34, and the McMichael rally not too far away. Didn't even know there was an Andover rally - I'll look out for that one. Any other good ones within an hour's motorcycle ride of Newbury?

Comparing hams with mechies is a low bar for comparison

[tggzzz]

Not worth a thread on its own, so here are a couple of pictures of the Agilent 8714ES 3GHz RF Network Analyser I picked up today at a hamfest viewtopic.php?p=11438#p11438

I almost didn't buy it because I already have reasonable 3GHz NanoVNA, and this nominally duplicates the functionality. Nonetheless I'm glad I did buy it, because it is easier to use (no farting around with calibration, but bigger and heavier) and has a better specification (unsurprisingly). The "begin" button is quite well done: the first thing you specify is the type of UUT, and that sets up all sorts of GUI and other options. Examples include filter, cable (for fault location), amplifier, mixer (i.e. frequency translation!)


So a few pictures of it operating, a couple showing the S11 reflection of whip antennas at the other end of a 3m RG174 cable

IMG_9395.JPG

IMG_9396.JPG

One showing the transmission and reflection of a homebrew 200MHz HPF. Haven't bothered to investigate the poor performance at 1.5GHz; might be the cable, might be poor SMD construction technique

IMG_9404.JPG

A couple showing the attenuation and reflection coefficient of a Weinshel 20dB 25W 8GHz attenuator.

IMG_9397.JPG

IMG_9403.JPG

No, I haven't looked at the PSU, but the vendor thought it would be OK in a way that I trusted him and the limitations of what he was saying.

[Zenith]

No, I haven't looked at the PSU, but the vendor thought it would be OK in a way that I trusted him and the limitations of what he was saying.

VNAs aren't really my thing. I was struck by the way he appeared knowledgeable and passionate about the subject, and was shocked by the good enough approach taken to 5GHz antenna design, then going on to describe the need for calibration and how much it cost to do things properly. I had the impression he had no patience for not doing things properly. Nano VNAs and Siglent VNAs were not to be taken seriously. He seemed pleased that this worthy piece of TE was going to a good home.

There was a brief discussion with his wife/partner, who was clearly delighted by the sale, until I mischievously suggested this was to make way for the 8714EZ model, which was twice as big, needed many more untidy cables, and boasted the YR15 rectilinear circumventer, which was a thing of beauty and joy, and which would grace their home. She would be the envy of her neighbours. Her face dropped.

I assisted with loading it onto a flatbed trolley and loading it into your motor. The least you can say for it, is that it's very muscle building.

After there was a discussion about Rifa capacitors. My view was that the name is cursed, and in this case there is such thing as guilt by association.

[Robert]

Nice "little" VNA (my 8720C is 6U high). I'm glad you can see it has advantages over the tiny and nano VNAs.
Reading the other thread I think you both got a good deal at £375. I had a 8754A & S parameter test set (both 2.6GHz version) at National Hamfest and didn't get any interest other than a couple of dealers discussing it's scrap gold value
No interest on ebay either.
You might think that the tiny and nanos would increase interest in the "proper" ones but it seems not. I guess the small ones are good enough for most people.

[tggzzz]

Nice "little" VNA (my 8720C is 6U high). I'm glad you can see it has advantages over the tiny and nano VNAs.
Reading the other thread I think you both got a good deal at £375. I had a 8754A & S parameter test set (both 2.6GHz version) at National Hamfest and didn't get any interest other than a couple of dealers discussing it's scrap gold value
No interest on ebay either.
You might think that the tiny and nanos would increase interest in the "proper" ones but it seems not. I guess the small ones are good enough for most people.

I think that's the case; NanoVNAs are good enough to see an antenna's centre frequency and width, and to check a filter's edge is where you want it to be. What more would a hobbyist need? Plus it seems many hams don't understand VNAs and S parameters - and don't want to

In general hobbyists are drifting away from boat anchors.

The person I bought the 8714 from said he had several other big 87xx, and that they tended to suffer problems with the transistors powering the YIG oscillators.

The poor performance I noted at 1.5-2GHz seems to be related to something happening intermittently near the channel 2 connector. I have not determined whether it is in the cable, an adaptor or (worse) the 8714 N connector. I may end up trying to find a sacrificial connector that does not exhibit any problems.

[Robert]

You are in luck with a dodgy connector on the 8714ES. Unlike most HPAK analysers the connector is not part of a bridge assembly. It's just a N to SMA adaptor. You can even order one from Keysight 08711-60038 .
Before you do that, pull the front panel and check the SMA connectors are tight including the iterconnections with the source module.
If you do need a connector, post a picture. I probably have one.

Robert.

[tggzzz]

Interesting; thanks. That gives me a simple test and a potentially simple cure.

It still isn't clear to me whether it is the VNA connectors, crap sacrificial connectors, or crap cables, or the combination of one connector with another. Currently I suspect is a crap sacrificial connector possibly with a poor cable. I can't rule out the VNA connector being "overused" and becoming worn.

More fun than soduku, at least.

[mnementh]

Interesting that conversation has turned to swapmeets in my absence; I was absent in part going to this:



I posted shedloads of pix in the Discord while I was there; I'll make an effort in the next few daze to get them up over here.

mnem

okay, so "next few days" was more like "next few weeks"... but pics are up over here: viewtopic.php?t=434

mnem
yes, you may touch it.

[bd139]

So went on a little trip at the weekend. Came across this bit of gear lurking in a museum. I have all the luck!

IMG_1350.jpeg