Test Equipment Anonymous (TEA) group therapy thread

[Robert763]

Hmm, so the 334A Distortion Analyzer is all back together and hasn't gone up in smoke since it was turned on.   
It's calibrating nicely so far with the new set of capacitors and metal film resistors in place of carbon comps.

BUT, it turns out I need a 600ohm feed through terminator for part of the calibration procedure.... Anyone got one they want to sell?

It's just two 1.2k resistors in parallel across the binding posts. If to want to be fancy to could put then in a diecast box with plugs and sockets. need 3 (hi lo and chassis) of these https://uk.farnell.com/tenma/72-13650/conn-banana-plug-36a-stud/dp/2930001?
and top hat nylon washers to make it look pretty.

EDIT. following comments made while I was typing  looked at the manual nd soo they call up a BNC terminator. This is on the 600R output of a 652A oscillator Correct part is 11095A
The 652A output is just a 550R resistor from the 50R outpu attenuator. The 600R temination will give half the voltage output (google hard soft microvolts)
If using a modern signal generator with a proper 600R output you don't need it but will have to reduce the output level by half (6dB)
Fi you really need a terminator I'd use a BNC T and a BNC to binding post adaptor with 2 x 1k2 resistors across the binding posts. That's the bit's I have to hand.

[mansaxel]

- connectors: Kathrein EMK 14

The compression plugs are essential. Remade my DVB-T net with them couple years ago. Zero issues, lots better signal.

[TERRA Operative]

It's just two 1.2k resistors in parallel across the binding posts. If to want to be fancy to could put then in a diecast box with plugs and sockets. need 3 (hi lo and chassis) of these https://uk.farnell.com/tenma/72-13650/conn-banana-plug-36a-stud/dp/2930001?
and top hat nylon washers to make it look pretty.

BNC connector, BNC T piece and a 602R E96 resistor will work.

I do have some little black aluminium boxes, just big enough to stick a finger through. I guess I could get a drill out and make something a little bit nice with some BNC connectors etc.

[Robert763]

see my edit unless using a old signal generator you don't need to terminate it.

[TERRA Operative]

see my edit unless using a old signal generator you don't need to terminate it.

I'm just using a 3325A function gen, and setting the RMS voltage to be as close as I can to what the manual calls for by measuring it on my 34461A multimeter

[Robert763]

see my edit unless using a old signal generator you don't need to terminate it.

I'm just using a 3325A function gen, and setting the RMS voltage to be as close as I can to what the manual calls for by measuring it on my 34461A multimeter

No termination required then 

[25 CPS]

So we are no longer Canucks in waiting; we are now US citizens only again. Even though the immigration lawyers told us we had all our LMIA stuff in order (and evidently we did), we didn't do the visitor status renewal thing correctly, and being stuck in the middle of a global pandemic was not good enough reason. We went to do the last part of the process as outlined by our lawyers; returning to the US and finalizing the LMIA at the border. However the visitor status problem borked that, and we spent 18 hours "not being detained" in the border station waiting area and our car before they told us officially to piss off back to the US.

We are at this moment regrouping just across the border in New York (no med, we're not coming to your idyllic little corner of the state), and going to visit my dad in NYC.

So short version: we're starting over. We may try the LMIA thing again depending on the results of the hearing, but by the time we get back on our feet and can think about such things, we'll probably be established somewhere close to my dad which is now my primary concern.

It was a nice, if very expensive, vacation.

mnem
*so very tired*

Is there an appeals process for this?  I’ve heard nothing but horror stories about how the pandemic has made a mess for immigration into Canada and international students coming here.

[Neomys Sapiens]

It must be audiophoolery week on my local CL. I guess I missed the memo. 

Sometimes I am glad that an explanation or title is provided with a picture.
The arrangement above had me thinking of completely different things.

[BU508A]

It must be audiophoolery week on my local CL. I guess I missed the memo. 

Sometimes I am glad that an explanation or title is provided with a picture.
The arrangement above had me thinking of completely different things.

Kind of a captivating connection perhaps? 

[0culus]

It must be audiophoolery week on my local CL. I guess I missed the memo. 

Pat sent me these wonderful scans of "MAD Magazine Goes Hifi". 

[capt bullshot]

Ever wondered what's inside a defective satellite dish LNB?

Krusty!

Any clue as to what component failed?

No, I didn't dig any further. But I assume it's corrosion that might have dissolved a PCB trace or shorted the output connectors, so I'd guess the components are still OK.
I don't think all the water ingress happened within one day that took the thing from working to fail with no early telltale signs. Rain obviously has less minerals than tap water, usually electrochemical corrosion by water intake is faster.

[capt bullshot]

Here's two more pictures of the RF voodoo inside the LNB:

Though I have an idea of what it is supposed to do, I have no idea how it is doing this. Can't even spot a local oscillator





Shariar (TSP) made a video about a simple radar, explaining these structures.



OK, now I see some:

The pinkish toroidal things most probably tune the local oscillators. With some imagination I can see wilkinson power splitters, mixers, and amplifier chains.

[med6753]

I built up the updated rectifier board for the mini 212. The 2 components on the tape are fuses for the battery packs. Mine already have fuses installed so these will be spares. The inter-board connectors won't be installed until I check clearances. They can be installed several ways which could cause clearance issues.

So, will it be installed today? Not happening. Tomorrow? Nope. Wednesday? Unlikely. But it WILL be installed before Christmas. 

[AVGresponding]

I built up the updated rectifier board for the mini 212. The 2 components on the tape are fuses for the battery packs. Mine already have fuses installed so these will be spares. The inter-board connectors won't be installed until I check clearances. They can be installed several ways which could cause clearance issues.

So, will it be installed today? Not happening. Tomorrow? Nope. Wednesday? Unlikely. But it WILL be installed before Christmas. 

You fitted R215 with the tolerance band at the wrong end!   

[med6753]

I built up the updated rectifier board for the mini 212. The 2 components on the tape are fuses for the battery packs. Mine already have fuses installed so these will be spares. The inter-board connectors won't be installed until I check clearances. They can be installed several ways which could cause clearance issues.

So, will it be installed today? Not happening. Tomorrow? Nope. Wednesday? Unlikely. But it WILL be installed before Christmas. 

You fitted R215 with the tolerance band at the wrong end!   

Have at it. 

[ch_scr]

Here's two more pictures of the RF voodoo inside the LNB:


OK, now I see some:

The pinkish toroidal things most probably tune the local oscillators. With some imagination I can see wilkinson power splitters, mixers, and amplifier chains.

To illuminate a bit more, find attached below an illustration of how the resonator couples to the microstrip: magnetically!

One strip couples energy into the resonator, the other gets the feedback to the active element.
I would hazard a guess the longer strip terminated at the right couples energy into the resonator (the strip that also goes left to the splitter) and the shorter stub 90 degree to it is the one that gets the feedback for the amplifier.
Still amazing over which distance the coupling takes effect!

[RolandK]

Selftest works, but it does not meassure, last time it did work. So had to use the one from the next side...

[Cerebus]

I built up the updated rectifier board for the mini 212. The 2 components on the tape are fuses for the battery packs. Mine already have fuses installed so these will be spares. The inter-board connectors won't be installed until I check clearances. They can be installed several ways which could cause clearance issues.

So, will it be installed today? Not happening. Tomorrow? Nope. Wednesday? Unlikely. But it WILL be installed before Christmas. 

You fitted R215 with the tolerance band at the wrong end!   

Have at it. 

I don't think that solder wick is going to work if it's soaked in urine.

[mansaxel]

Pat sent me these wonderful scans of "MAD Magazine Goes Hifi". 

They're really nice. Thanks.

[Cerebus]

Selftest works, but it does not meassure, last time it did work. So hat to use the one from the next side...

I was going to say "Bitte auf Englisch!", but you'd edited it while I was saying it! Now I'm just getting confused because I was also trying to translate Shakespeare first lines in German on University Challenge to English at the same time.

[mansaxel]

The RV55 has arrived. In one piece, and visually good condition. Nothing seems broken, no transport damage. Happy.

Also: The instrument is bleeping enormous. Compare to the 8060 -- I thought I was lucky getting a large instrument on my -hp- 400H (which was, at the time, marketed as having a larger display than its elder brethren). This easily is 35-40% larger than the 400h.  Gorgeous in every way. No internal pics yet; I literally took it out of the package and switched it on. (It gets quite cozy.) 

It unfortunately reads only about 90% of actual value. The TT-15 puts out 1030mV 1KHz according to the 8060, but as you see, that only shows up as 900mV on the RV55. I'll parallel the meters to check it's not loading the Fostex, though. It should not; it's a 1MΩ input impedance instrument, but the TT-15 is not the highest quality source available, so while trust might be good, it's surpassed by control...

[Specmaster]

The projects in Brooklyn, NYC. No different than the one's in Queens. When those projects were built in the early 1960's the requirements to gain residence were quite different. You HAD to demonstrate that you were employed. Jo Ann and her family were the first occupants of the apartment when the building opened. Her Father worked at the Brooklyn Navy Yard. Over the years the city allowed the buildings to deteriorate and the residency requirements became all you needed was a pulse. Jo Ann has told me stories of living there and initially it wasn't too bad but over the years quickly went downhill.

Fast forward to today. Jo's grand daughter and her deadbeat daughter-in-law live in the exact same building. Her daughter-in-law has not worked one day in her life and is on the dole (welfare). Luckily her grand daughter is now 17 and a straight A student and headed for college and break out of projects. And Jo's older 2 grand son's also left dead beat momma behind and are gainfully employed and living outside the projects.

I once drove Jo and her grand daughter over to the building to drop her off after visiting for the weekend. I was told to stay in the car. I was the wrong color. Trust me, I had no issue with that.     
 

If you follow Louis Rossman then you'll have seen how the City has allowed all of NYC to deteriorate with almost 1/3 of businesses closed, roads unrepaired and the city authorities and landlords appear to be desperately chasing the last few $ from what business is actually left in the city and in so doing driving away the remaining businesses as they cannot afford the excessive rents and business rates any longer. It's really loosing its once glamorous and glitzy reputation, with large parts of it becoming almost a ghost town.

[BU508A]

Here's two more pictures of the RF voodoo inside the LNB:

Though I have an idea of what it is supposed to do, I have no idea how it is doing this. Can't even spot a local oscillator





Shariar (TSP) made a video about a simple radar, explaining these structures.

https://www.youtu.be/5vqSX40seqA

OK, now I see some:

The pinkish toroidal things most probably tune the local oscillators. With some imagination I can see wilkinson power splitters, mixers, and amplifier chains.

What I am finding fascinating is that those LNBs are working on a wide temperature and humidity range for many years (10 years and more aren't unusual). I'm always wondering, what the hidden knowledge is constructing these amazing circuits. But I'm afraid that those things are kept as a well guarded secret (the devil is in the details with all this RF stuff).

[beanflying]

With a little creativity I can see a set of HAM inspired shelf brackets or table legs  eBay auction: #255230237171

[cyclin_al]

I built up the updated rectifier board for the mini 212. The 2 components on the tape are fuses for the battery packs. Mine already have fuses installed so these will be spares. The inter-board connectors won't be installed until I check clearances. They can be installed several ways which could cause clearance issues.

So, will it be installed today? Not happening. Tomorrow? Nope. Wednesday? Unlikely. But it WILL be installed before Christmas. 

You fitted R215 with the tolerance band at the wrong end!   

Have at it. 

Ooooh!  Now that is a copper rope