I bought a nano VNA S-A-A-V2 a while ago (turns out it was a clone) and was impressed by the two 12 inch SMA cables it came with. They aren't your ordinary cheap cables. So I looked on eBay for someone selling cables with blue insulation like those. I found something and ordered three 12 inch cables: one RG402, one RG405 and one LMR195 from bydpete (about $4 US each). I just got them today and measured them along with two random RG316 cables (I have PILES of random RG316 cables accumulated over the years) and I like the LMR195 cable. I attribute the ripple in the S21 response to the SMA connectors. I read that the seller can offer cables with better connectors, so I've sent a message asking about that.
In the picture the cable that came with the nano VNA is on top. The three cables I just purchased are below it. The two random RG316 cables (beige color) are at the bottom. The RG402 and RG405 are semi-rigid, the LMR195 is more flexible. The nano VNA cable is also very flexiible. Wish I knew how to get some more of those. I used to work mostly <1GHz, but have more recently been doing stuff at 5.8 GHz. You can't just grab any cable out of your pile for that.
Does yours also have auto-calibration mode ?
Yep it has internal calibration, and apparently it can self-level too!
It can be a bit scary buying a balance with internal calibration because you're supposed to "lock" the weight by turning a screw or something so it doesn't move while shipping but chances are when dealing with sellers on auction sites, they won't do this. Fingers crossed.
Now I'm on the hunt for a nicer battery powered one...for the two times a year I have a barbecue outside.
(ignore the fact that I can't think of a use case yet)
From one of our local 'antiques' emporiums: Item described as "Old Tin" for £5, turned out to be an unused NATO Hellermann wire stripping set. It comprises a decent Ideal [Custom] Stripmaster automatic wire stripper with 4 different size sets of metric blades (15 diameters), a flat cable shear, and two different sized Ideal coax cable strippers, again with spare blades. Things needs a bit of a clean up due to age everything is clearly unused.
Edit: I've just looked up the prices of the mil spec Custom Stripmaster and blade sets. Maybe I should trade it for a scope!
I have been busy buying up even more test gear in the last couple of weeks. Not what I could honestly describe as " a score" as I paid a fair price.
Not pictured are a Datron 4910, 3x Fluke 732A, plus a couple of high quality resistor standards by Welwyn but all included in my latest attempt to complete a home cal lab.
If anyone has information or manuals for the Datron 4901/4902S/4903 I would be grateful for any information about this antique setup. My plan is to upgrade my calibration equipment & sell whatever is surplus to get some of my money back before the next opportunity to spend comes along. I hope that this will keep me happy for a long time but I suppose it all depends on what I find next.
Cheers
Phil
arrived today, a 'pb' < 18-hours from online order:
an RS-135 4-20mA Loop Calibrator & Thermometer (description from Instructional Manual)
aesthetically not exactly a looker and non-calibrated - but so is the 121GW I've just hooked it up to, they are at least both in agreement.
Something of an odd couple?
couple made sensible with a wall port - the RS-135 is measure only for temperature
A wavetek 2002A
(Attachment Link)
Waaahh!! I want one!
I've been looking for them on eBay for years, but they are fairly rare.
We used to use them back in the day, when we ran out of RS SWOB Polyskops to take on maintenance runs.
The Polyskop was the "preferred option" & to be fair, is a bit more "user friendly", plus has that
BIG screen, but a 'scope & a 2002A don't stretch your arms as much!
I just picked up a Picoscope 5244B on epay. It is a 2-channel, 200 MHz scope with variable 8-16 bit resolution, 512 MB of memory and a built-in 20 MHz AWG. Dave did a teardown of a model in this series (5443B) a bunch of years ago at a trade show. I got it for $450 with the nice Picotech 250 MHz probes, which I think is a fair price since the retail was $1975 and the new version (5244D) goes for $2315. However, the seller accepted my offer so quickly it makes me wonder if I could have gotten it for an unfairly low price!
In any case, it is quite the upgrade from the pico 2204a that has been my only scope for the past handful of years.
I just picked up a Picoscope 5244B on epay. It is a 2-channel, 200 MHz scope with variable 8-16 bit resolution, 512 MB of memory and a built-in 20 MHz AWG. Dave did a teardown of a model in this series (5443B) a bunch of years ago at a trade show. I got it for $450 with the nice Picotech 250 MHz probes, which I think is a fair price since the retail was $1975 and the new version (5244D) goes for $2315. However, the seller accepted my offer so quickly it makes me wonder if I could have gotten it for an unfairly low price!
In any case, it is quite the upgrade from the pico 2204a that has been my only scope for the past handful of years.
You snagged a real bargain, don't second guess it. That is if it is in undamaged working order.
me jelly
Tektronix 7L5 Spectrum Analyzer plug-in with OPT 25 tracking generator excellent condition but months to get payment, packaging and shipping negotiations...finally hand carry on 11 hrs flights
Loading in 7603 and 7904 Tektronix mainframes, the scopes needed astigmatism and geometry trim on Z axis PCB, for a bright, clear, focused and aligned display. Unearthed my old 7L12 as well
The 7L5 had A few flaky connections, after contact cleaning, in CAL, dated circa 1980!
Pix of both scopes and Spectrum Analyzers, with CAL Signal and HP 8640A with wideband FM modulation.
your thoughts?
I just picked up a Picoscope 5244B on epay. It is a 2-channel, 200 MHz scope with variable 8-16 bit resolution, 512 MB of memory and a built-in 20 MHz AWG. Dave did a teardown of a model in this series (5443B) a bunch of years ago at a trade show. I got it for $450 with the nice Picotech 250 MHz probes, which I think is a fair price since the retail was $1975 and the new version (5244D) goes for $2315. However, the seller accepted my offer so quickly it makes me wonder if I could have gotten it for an unfairly low price!
In any case, it is quite the upgrade from the pico 2204a that has been my only scope for the past handful of years.
You snagged a real bargain, don't second guess it. That is if it is in undamaged working order.
me jelly
I know you are right. And it works great - used tinySA as source and bandwidth is 200 MHz as advertised, high-resolution modes show great detail, signal generator is really nice, etc. The cosmetic blemish I was expecting based on the ebay photo turned out to be a piece of scotch tape on the front panel that just peeled off! I am very happy with it.
But My neurosis has included a bad case of the doubters disease for as long as I can remember….
Cheers!
Jason
If anyone has information or manuals for the Datron 4901/4902S/4903 I would be grateful for any information about this antique setup.
This is a unique set. I envy you very much.
Here is everything that is on 4902:
Picked up a second hand Hioki clamp on probe Model 9008
I needed some new speakers for by my test bench and I came across some sales on Newark(Farnell) and I bought two sets of these Bluetooth ceiling speakers for $10.37usd (was $122.00usd) per pair.
For that price I am not expecting much, but they came today and I am unboxing now, will update here shortly.
It includes 24v 2.5Amp 50/50hz power brick.
The instruction book says enter 0000 as the Bluetooth pin, but that doesn't work. Password printed on the back of the active speaker DOES work.
no base, but given the stated frequency response as 60hz-120khz that is no surprise, not being an enclosure right now doesn't help much me either me thinks.
with 30watts RMS per speaker there is not a lot of volume being driven by my windows10 desktop, but for ~10.00 for a pair, I am pretty happy right now.
https://www.newark.com/stellar-labs/50-16617/6-5-active-ceiling-speaker-pair/dp/25AC5146
Thought I would need a laser engraver, so I bought one. Atomstack A5pro+. This was cheap to start with. First test, laser power was a little high (from the database).
I bought five NEMA17 steppers from VEVOR. Includes wire stripper/cutters and electrical tape, not sure why since they have dupont connectors.
Oh it doesn't include the wire stripper, its
equipped with a stripper:
【EFFORTLESS TO USE】- The stepper motor is equipped with a wire stripper commonly used by internal electricians, motor repairs, and instrument electricians to strip plastic & rubber insulated & cable core wires. Insulating rubber tape with excellent insulation performance and good adhesion to prevent leakage.
What a terrible thing to include with stepper motors. Someone out there is twisting wires together and then taping them up, making the worst connection on earth.
Thought I would need a laser engraver, so I bought one. Atomstack A5pro+. This was cheap to start with. First test, laser power was a little high (from the database).
Big thing to be really careful with open Laser engraving or cutting is where the beam can go if reflected and what fumes/poisons is the material giving off. At minimum open doors and windows but far better put a proper cover over it with extraction to the outside both for your lungs and eyes.
So many MORONS with 'free' ones of theses on youtube literally blowing smoke up Bangoods ass while simultaneously sucking it into their lungs.
Play Safe
I had to restart a computer today and when I did, for some reason it couldn't get a network connection. I noticed the LEDs on the switch it was plugged into were blinking in a mad, crazy pattern. I tried the usual fixes but only bypassing the switch and going directly to the router worked. I used the same port as the switch, so the router isn't part of the problem. My NAS was also plugged into the switch and to get it back I'd have to disconnect a printer. No real problem as I have only used the printer once or twice in the last year, but I decided to buy a new switch just to put things back as they were.
I got something around 10 years of use from the switch, so I didn't have any problem buying its successor. It's even cheaper.
https://www.amazon.com/gp/product/B00A128S24/To ensure some future fun, I added the 8-port "managed" version to my order. Considering I now qualified for "free" shipping, it almost cost less than the 5-port version.
I'm thinking I should also buy some kind of back up router - just in case. Electronic stuff tends to fail at odd times for strange reasons. Last year, as far as I could tell, my cable modem died because of loud thunder.
Big thing to be really careful with open Laser engraving or cutting is where the beam can go if reflected and what fumes/poisons is the material giving off. At minimum open doors and windows but far better put a proper cover over it with extraction to the outside both for your lungs and eyes.
Used it outside for testing and probably will do so ever. Enclosure to come.
This atomar thing has no end stops
Homing will run the mechanics to the ends and then fail
So have to take a look if and where to attach switches. Laser reflection is greatly reduced as the head is only 2mm from the surface.