The whole reason I watch this channel is that its so advanced that I have only like 2% chance of knowing whats going on at the beginning of each video. If by the end i'm up to 10% of knowledge, I consider it a positive. If not, oh well, it was still cool. But you usually do a good job explaining, its not your fault.
I agree, it's not Shariar fault I don't understand something; however, it did seem that Shariar did slow things down a little bit in this video, which indeed seemed to help me understand a little more of what was going on.
I can only DREAM that I'd start watching a TSP video at a 2% level and end up at 10%... I would GUESS that I'm more like 2ppm ending at 10ppm! (But I am definitely NOT complaining!!! I'm still learning from each and every video he makes!) I'd suggest that I am more of a DC guy (assuming DC is anything below the 2.4GHz ISM band)
When I started this hobby everything was too advanced. I humbly accepted the challenge and now I praise myself for being able to actually understand most of your analysis, especially during repairs. Keep it up, our brains cannot grow fast enough with regular food
I really appreciated the extra effort you made to explain in greater detail, since I'm one of those people who feels that the subject material mostly passes right over my head. I still watch though, because I always learn something. Thank you so much!
I remember working with these, testing and tuning optoelectronic components. It seems like yesterday but was almost 20 years ago now. We had "Connector Savers" screwed to the front to try to limit the wear on the front ports as the cabling was often reconfigured, though even those devices themselves would have some impact on S-parameter measurements.
Great content as usual Dr.shahriar , I really like your advanced videos I mean this is the only youtube channel that have the capabilities to demonstrate such topics.
Great video! You did a wonderful job explaining something that was, and still is "over my head". A lot of the principles here apply to other types of circuits like switches for amateur radio antennas for example. Thank goodness I have some knowledge there or I'd be completely lost instead of just overwhelmed. I would also suggest watching videos on Nano VNA's to further understand this. For about $50 on Ebay you can get one of these and just play with it. No it's not an HP, but not $20,000 either and great for learning on. I'd imagine that if you could familiarize yourself with the Nano VNA first, this video would be MUCH easier to grasp. W2AEW has some excellent videos on this. Thanks again Shahriar.
This gives me more appreciation of what went into these finely crafted instruments especially in the benefit they provided in my own testing over the years. Nothing quite like a piece of HP gear before the reorganization of the test engineering group.
I would like to see the instrument used to measure the torque of the screw on the bottom of the SRD assembly which says 2 in-ozs...that's an absolutely miniscule amount of torque.
Better than porn! Please don't slow down on the advanced stuff! Some of your content is within my abilities and much is way over my head -- but it's the over-my-head stuff that helps me grow the most. I have gained sooooo much from your channel. It has opened up whole new worlds of enjoyment of the hobby for me and greatly expanded my abilities. That said, the videos you do on the basics are very useful too. So I think you're on the perfect track with your selection of topics.
The 8510 is a beast of a system which was available with front-ends capable of analysis up to 110GHz. I could personally see RF labs holding on to these for as long as they can keep them going due to the wide-scale adoption of millimeter-wave technologies.
I'd be very interested in looking what's inside the VTO sampler and the step recovery diode, ie that part of the unit that generates the IF from the VTO LO and the input from the Test Set. Many thanks, N.
Loved it. Although I like your other types of videos too, I have always wondered about the details of the internals of S parameter test sets. I knew basically what was inside, but hadn’t actually seen inside one until now. Thank you! I’m also interested in the VTO, so looking forward to when you show it in more detail. 😀
I would certainly be interested in a teardown of the VTO (not to mention any further analysis of the Starlink antenna, on the off chance that is still of any interest to you).
Shahriar yes please do as Amcia Apple suggests and maybe make that "back to basic" such that over time have you filled the gap from noob to advanced. :-) Edit: Sorry forgot to write, you have so much amazing gear that mostly is outside what a noob can use or understand. Why not once in a while talk about the gear that will be great for one that wants to start the journey out in HF?
@@friedmule5403 , It is hard for someone like Shariar to instruct such a wide variety of human needs. Perhaps some basics as to "things the average person may need to measure what needs to be measured in a home lab or in an amateur radio situation." I might suggest what types of STANDARDS are available and necessary, also.
I assume the influx of these comments is due to the growth of the channel. In the beginning most viewers were working in the field or people that are into this equipment due to their hobby. Over time the channel attracted more of the general electronics people who don't necessarily have a background in HF electronics. I agree that a HF basics series would make sense as it would build a catalogue of videos to reference the questionnaires to, thus reducing questions about basics in the comments.
@@BruceNitroxpro You are perfectly right! I look at it like this, Shariar is an amazingly skilled person in a field of electronics not many matches and it would be a big loss if Shariar converted his channel to a beginner channel, you find hundreds of channels for the beginner. And to be honest, if you need to learn about Ohms law while following this channel, then are you on the wrong channel. But Shariar is so far beyond the next channel in some situations that there is nobody to close the gab and since Shariar is maybe one of the leading experts in HF and have taken the journey from noob to expert do I feel he may be the single best to advise on i.e. gear, because he does not only understand the needs but also understand the gear in ways even the designers may not understand. :-)
It may have been worthwhile to power up the unit while to was still in one piece and diagnose the fault(s,) whether you intended to repair it, or just salvage its parts. This would give you some indication of what components were stressed and, therefore, what parts might be suspect for precision work, when later used. Yes, each independent part could be tested, and should be, before use, of course. However, an "it still works" diagnoses is different than a "It still works, but it was subjected to (for example) a reverse polarity condition." Just a thought. Love your channel!
I would be interested to see one of those rigid coaxes cut open. I am also curious how the coax itself is fabricated as well as how the connectors are attached.
As always great video! I would like to see not only experiments but may be some useful design based on those components ;) Lets see for example automatic attenuator > small control unit to set the required output and when you apply input signal output will be adjusted accordingly by attenuators. That's only one idea and I'm sure there is more.
Shahriar, as you can see in another comment, some of your viewers including me had a first world problem with this video. We had to wait a good 15 minutes or so to view this video in HD while youtube was encoding. While I was watching it, the only option was 360p. Can't speak on behalf of anyone else but I am genuinely fascinated with your videos and I always make time for them because I have learnt so much from you in the past. It is just so painful to wait for high quality version :).
15:35 This explains things, Shahriar is obviously not in the same universe as the rest of us. Though, 1 minor complaint about the video, the intro and outro music is a fair bit louder than when you are talking. I would recommend keeping an eye at the sound level when editing. You could throw on an audio compressor when you talk, this will level out the volume fairly effectively, but configuring such to not sound poorly is a bit of an art. I am though biased in regards to sound, being an audio technician for a fair few years have made me picky about audio leveling and editing...
@@Thesignalpath It isn't a huge difference. But it is a bit loud, or it could be the rest of the video that is on the quiet side. But a few tips and tricks. I think you can get an audio track visualizing the volume over time in most video editors. Giving you the ability to quickly see any drastic changes. A general rule of thumb is to aim to be within about 3 dbc from one audio clip to the next for it to have a similar volume. It is generally more important to watch the average volume than the peak volume. (box car over a few hundreds of ms. (Audio techs still use panel meters for a reason, they have "good" averaging.)) After all, a regular person talking at 60 db can still reach peak volumes up in the high 70's. In regards to volume differences, a 10 db increase is generally considered to be about twice as loud by the human ear. Staying within 5 db is a noticeable change by most people. And 10-15 db is the difference between someone talking quietly in a movie, and an explosion packed action scene. One can use a drop in reference sound as a sanity check and then just get it in the same ballpark by ear. If the reference is louder than the video itself or vice versa, then there is an imbalance in the level and one then changes the video's audio level accordingly. (A reference sound can be almost anything, except a pure tone since that is clearly heard through almost anything, the ear is practically a real time spectrum analyzer. With 1 selectable input attenuator of about 15 db, controlled by the stapedius muscle during the the acoustic reflex) One reference clip could be the intro music itself. Another advantage of a reference audio clip is consistency from one video to the next. One can also use an audio compressor to flatten the volume, but this is generally more useful if one live streams. Since it can compensate for varying distances to a microphone or sudden loud sounds etc. (I though use a compressor on live performances to save me the time of twiddling the fader when people hand a mic back and forth between each other.) Also, in regards to the complexity of the video topics, I think it honestly is nice. Sometimes you are talking about things way above my understanding, but I have learned a lot. Though still have glaring gaps in my knowledge, like QAM modulation is something I understand, but single side band without tons of filtering is magic... I partly understand it, but can't explain it. Would also be nice to know more about RF couplers and how they differ from circulators.
@@NoahFect thanks for bringing this to my attention, you made me look at the amazing comment chain by dunsmore. The patent is shockingly understandable, I had expected it to be fully patent-speak, but it looks like it was at least in part written by engineers, not lawyers. Those were the good old days :D
Right now on ebay there is a complete unit for just under $500. This is considered obsolete by the industry. There still are people out there "upside down" on these instruments trying to sell them for higher price than more modern instruments can be bought for!
Everybody wants to know how much this stuff is worth, so I looked for any items that had an identifiable part number and looked them up; most are older parts found on eBay, some are still available from Keysight. eBay prices were just quick surveys from scrolling, not mathematical averages. @9:32 HP 5086-7324 coaxial switch splitter $100 eBay @10:20 HP 33323V 26.5GHz 0-90dB step attenuator $250 eBay @11:00 Keysight 8493C dc26.6GHz fixed attenuator $506 Keysight @12:00 the item identified as a bias T has the same part number as the coax splitter. Hmmm. @16:05 4x 5086-7402 sampler assembly $100 ebay (part of quad mixer) @21:00 HP 50867231 VTO/Driver assembly $200 ebay
Those prices are for suckers. There is a whole unit for under $500 right now on ebay. They are not that rare. The REST of the system is what is expensive!
Hi Shahriar, I got a 8510c with a 8516A test set. I wish to add the option 001 (IF switch to connect others test set) because I was build millimetric setup and I wish to siwtch automatically. You have info about how works and if is possible to remove from a 8515 for example and add it to the 8516? my twitter is @eb3frn tnx!
I am curious about the specific difference in the built between 2 VNA bridge heads and these bulky couplers and sampling mixers. The actual mini VNAs from KS use a custom chip which integrate a coupler PI-network, 2 differential amplifiers and 2 downconversion mixer, driven from the same LO, converted to a relative low IF and then get digitized. The PI coupler, as the remaining components work from DC up the parasitic deorientation of the diffamp CMRR and the bridge cap load. Is there a reason for this built or simply squeeze IC tec this down up to 26GHz where the 80s 1Ghz was a an IC wall?
@Joel Dunsmore Thanks Joel. So IC technology is here indeed the main driver. The bridge with a typical 2/3 and 1/3 divider and 2 diffamps should be anyway significant smaller than a wavelenght. Where the directional couplers operation is based on size large to the wavelength. Mixer, ADC and processing profit obvious from IC tec. Key point is: Wave direction could measured with a simple voltage divider.
have used the same superb equipment back in the early 90's , it is a real jewel , very good to use , and today I bet associated with a digital scope with fast and deep memory would be still the best S parameter tool !! 100dollars for this is scandalous , but who knows what it is today of soft engineers ... ....
The whole reason I watch this channel is that its so advanced that I have only like 2% chance of knowing whats going on at the beginning of each video.
If by the end i'm up to 10% of knowledge, I consider it a positive. If not, oh well, it was still cool. But you usually do a good job explaining, its not your fault.
mrlithium , It is hard to fault Shariar for anything.
I agree, it's not Shariar fault I don't understand something; however, it did seem that Shariar did slow things down a little bit in this video, which indeed seemed to help me understand a little more of what was going on.
I can only DREAM that I'd start watching a TSP video at a 2% level and end up at 10%...
I would GUESS that I'm more like 2ppm ending at 10ppm! (But I am definitely NOT complaining!!! I'm still learning from each and every video he makes!)
I'd suggest that I am more of a DC guy (assuming DC is anything below the 2.4GHz ISM band)
I agree, same here, but even then its still very advanced now all the time...
When I started this hobby everything was too advanced. I humbly accepted the challenge and now I praise myself for being able to actually understand most of your analysis, especially during repairs. Keep it up, our brains cannot grow fast enough with regular food
I really appreciated the extra effort you made to explain in greater detail, since I'm one of those people who feels that the subject material mostly passes right over my head. I still watch though, because I always learn something. Thank you so much!
Please keep the advanced content. I learn something new every time I watch your videos.
I remember working with these, testing and tuning optoelectronic components. It seems like yesterday but was almost 20 years ago now. We had "Connector Savers" screwed to the front to try to limit the wear on the front ports as the cabling was often reconfigured, though even those devices themselves would have some impact on S-parameter measurements.
Great content as usual Dr.shahriar , I really like your advanced videos I mean this is the only youtube channel that have the capabilities to demonstrate such topics.
It's always nice to see how something is built and what can be reused, so I would definately like to see more videos like this.
Great video! You did a wonderful job explaining something that was, and still is "over my head". A lot of the principles here apply to other types of circuits like switches for amateur radio antennas for example. Thank goodness I have some knowledge there or I'd be completely lost instead of just overwhelmed. I would also suggest watching videos on Nano VNA's to further understand this. For about $50 on Ebay you can get one of these and just play with it. No it's not an HP, but not $20,000 either and great for learning on. I'd imagine that if you could familiarize yourself with the Nano VNA first, this video would be MUCH easier to grasp. W2AEW has some excellent videos on this. Thanks again Shahriar.
This gives me more appreciation of what went into these finely crafted instruments especially in the benefit they provided in my own testing over the years. Nothing quite like a piece of HP gear before the reorganization of the test engineering group.
I would like to see the instrument used to measure the torque of the screw on the bottom of the SRD assembly which says 2 in-ozs...that's an absolutely miniscule amount of torque.
I appreciate you working to help bring this down to my level!
HP 8515A is just what I wanted for my hobby setup, I cry later !
Better than porn! Please don't slow down on the advanced stuff! Some of your content is within my abilities and much is way over my head -- but it's the over-my-head stuff that helps me grow the most. I have gained sooooo much from your channel. It has opened up whole new worlds of enjoyment of the hobby for me and greatly expanded my abilities.
That said, the videos you do on the basics are very useful too. So I think you're on the perfect track with your selection of topics.
Pixel Schnitzel , Well said. I agree!
The 8510 is a beast of a system which was available with front-ends capable of analysis up to 110GHz. I could personally see RF labs holding on to these for as long as they can keep them going due to the wide-scale adoption of millimeter-wave technologies.
I'd be very interested in looking what's inside the VTO sampler and the step recovery diode, ie that part of the unit that generates the IF from the VTO LO and the input from the Test Set. Many thanks, N.
Loved it. Although I like your other types of videos too, I have always wondered about the details of the internals of S parameter test sets. I knew basically what was inside, but hadn’t actually seen inside one until now. Thank you! I’m also interested in the VTO, so looking forward to when you show it in more detail. 😀
Another great episode!
great video as always. more of these will be interesting
Wish so much to see the internals of those triax bridges.
I would certainly be interested in a teardown of the VTO (not to mention any further analysis of the Starlink antenna, on the off chance that is still of any interest to you).
Keep the advanced content but do a "Back to Basics" episodes once in a while.
Shahriar yes please do as Amcia Apple suggests and maybe make that "back to basic" such that over time have you filled the gap from noob to advanced. :-)
Edit: Sorry forgot to write, you have so much amazing gear that mostly is outside what a noob can use or understand. Why not once in a while talk about the gear that will be great for one that wants to start the journey out in HF?
@@friedmule5403 , It is hard for someone like Shariar to instruct such a wide variety of human needs. Perhaps some basics as to "things the average person may need to measure what needs to be measured in a home lab or in an amateur radio situation." I might suggest what types of STANDARDS are available and necessary, also.
I assume the influx of these comments is due to the growth of the channel. In the beginning most viewers were working in the field or people that are into this equipment due to their hobby. Over time the channel attracted more of the general electronics people who don't necessarily have a background in HF electronics. I agree that a HF basics series would make sense as it would build a catalogue of videos to reference the questionnaires to, thus reducing questions about basics in the comments.
@@BruceNitroxpro You are perfectly right! I look at it like this, Shariar is an amazingly skilled person in a field of electronics not many matches and it would be a big loss if Shariar converted his channel to a beginner channel, you find hundreds of channels for the beginner. And to be honest, if you need to learn about Ohms law while following this channel, then are you on the wrong channel. But Shariar is so far beyond the next channel in some situations that there is nobody to close the gab and since Shariar is maybe one of the leading experts in HF and have taken the journey from noob to expert do I feel he may be the single best to advise on i.e. gear, because he does not only understand the needs but also understand the gear in ways even the designers may not understand. :-)
@@friedmule5403 yeah, it's just such a big jump from the next thing down
I’d really like to see a video of you trying to fix the bias tee :)
It may have been worthwhile to power up the unit while to was still in one piece and diagnose the fault(s,) whether you intended to repair it, or just salvage its parts. This would give you some indication of what components were stressed and, therefore, what parts might be suspect for precision work, when later used. Yes, each independent part could be tested, and should be, before use, of course. However, an "it still works" diagnoses is different than a "It still works, but it was subjected to (for example) a reverse polarity condition." Just a thought. Love your channel!
I'd take it all to bits, great video as always!
Thanks for another great video!
Now the eBay prices are going to go through the roof :P
great video - now to find the nearest electronics surplus store...
So why use a sampler instead of a mixer? Can you show how those samplers work?
Advanced is fine. Outstanding video as per usual, thanks!
digging gold man in that box !!
I would be interested to see one of those rigid coaxes cut open. I am also curious how the coax itself is fabricated as well as how the connectors are attached.
The full network analyzer using this test set is HUGE, I just used the 50 GHz one very recently
As always great video! I would like to see not only experiments but may be some useful design based on those components ;)
Lets see for example automatic attenuator > small control unit to set the required output and when you apply input signal output will be adjusted accordingly by attenuators.
That's only one idea and I'm sure there is more.
What are the lab tables you use? I'm moving and looking to get something like those
Please, teardown the directional couplers! I'm begging you! XD
That's excatly my thought too.!
High directivity 45MHz - 26.5 GHz directional couplers a an engineer's masterpiece !
Which video has the VNA with the resistive coupler in it? Or what VNA outside of low cost hobbyist stuff like NanoVNA v1?
Ouch, attaching terminator by rotating body on the 3.5mm connector.. ;)
He was just 'polishing' them!!!
Shahriar, as you can see in another comment, some of your viewers including me had a first world problem with this video. We had to wait a good 15 minutes or so to view this video in HD while youtube was encoding. While I was watching it, the only option was 360p. Can't speak on behalf of anyone else but I am genuinely fascinated with your videos and I always make time for them because I have learnt so much from you in the past. It is just so painful to wait for high quality version :).
Glad you like the videos. I don't actually control the processing. TH-cam sometimes takes longer for the 1080p version to become available.
I want to see inside all the modules you can open without causing harm!
15:35 This explains things, Shahriar is obviously not in the same universe as the rest of us.
Though, 1 minor complaint about the video, the intro and outro music is a fair bit louder than when you are talking. I would recommend keeping an eye at the sound level when editing.
You could throw on an audio compressor when you talk, this will level out the volume fairly effectively, but configuring such to not sound poorly is a bit of an art.
I am though biased in regards to sound, being an audio technician for a fair few years have made me picky about audio leveling and editing...
Thanks for the feedback. I’ll turn the intro music down.
@@Thesignalpath It isn't a huge difference. But it is a bit loud, or it could be the rest of the video that is on the quiet side.
But a few tips and tricks.
I think you can get an audio track visualizing the volume over time in most video editors. Giving you the ability to quickly see any drastic changes.
A general rule of thumb is to aim to be within about 3 dbc from one audio clip to the next for it to have a similar volume.
It is generally more important to watch the average volume than the peak volume. (box car over a few hundreds of ms. (Audio techs still use panel meters for a reason, they have "good" averaging.)) After all, a regular person talking at 60 db can still reach peak volumes up in the high 70's.
In regards to volume differences, a 10 db increase is generally considered to be about twice as loud by the human ear. Staying within 5 db is a noticeable change by most people. And 10-15 db is the difference between someone talking quietly in a movie, and an explosion packed action scene.
One can use a drop in reference sound as a sanity check and then just get it in the same ballpark by ear. If the reference is louder than the video itself or vice versa, then there is an imbalance in the level and one then changes the video's audio level accordingly. (A reference sound can be almost anything, except a pure tone since that is clearly heard through almost anything, the ear is practically a real time spectrum analyzer. With 1 selectable input attenuator of about 15 db, controlled by the stapedius muscle during the the acoustic reflex) One reference clip could be the intro music itself. Another advantage of a reference audio clip is consistency from one video to the next.
One can also use an audio compressor to flatten the volume, but this is generally more useful if one live streams. Since it can compensate for varying distances to a microphone or sudden loud sounds etc. (I though use a compressor on live performances to save me the time of twiddling the fader when people hand a mic back and forth between each other.)
Also, in regards to the complexity of the video topics, I think it honestly is nice. Sometimes you are talking about things way above my understanding, but I have learned a lot. Though still have glaring gaps in my knowledge, like QAM modulation is something I understand, but single side band without tons of filtering is magic... I partly understand it, but can't explain it. Would also be nice to know more about RF couplers and how they differ from circulators.
Thanks!
It would be interesting to see some communications stuff - as in, things you can speak over, ham radio style.
21:40 are the bias connections wire wrap, soldered, or both?
Both.
I'm sure we have some of these on the surplus shelf. I'm going salvage them now! Asset tag be damned!
Why am I not seeing 1080p option?
i was gonna ask the same thing, why?
TH-cam takes time to convert videos longer than 10 minutes, try back in 20 minutes
Very nice teardown, but... where is Pooch?
Yay new video
I guess that report could be delayed another week
What's the internal architecture of the triax bridges? Google isn't coming up very helpful
One of the other comments references Julius Botka's patent. It's very informative, worth looking up.
DrJoel's book is also a good resource.
@@NoahFect thanks for bringing this to my attention, you made me look at the amazing comment chain by dunsmore.
The patent is shockingly understandable, I had expected it to be fully patent-speak, but it looks like it was at least in part written by engineers, not lawyers. Those were the good old days :D
I'd love to know the rough prices of the value of some of those bits. I googled and was fascinated 👍
Right now on ebay there is a complete unit for just under $500. This is considered obsolete by the industry. There still are people out there "upside down" on these instruments trying to sell them for higher price than more modern instruments can be bought for!
Everybody wants to know how much this stuff is worth, so I looked for any items that had an identifiable part number and looked them up; most are older parts found on eBay, some are still available from Keysight. eBay prices were just quick surveys from scrolling, not mathematical averages.
@9:32 HP 5086-7324 coaxial switch splitter $100 eBay
@10:20 HP 33323V 26.5GHz 0-90dB step attenuator $250 eBay
@11:00 Keysight 8493C dc26.6GHz fixed attenuator $506 Keysight
@12:00 the item identified as a bias T has the same part number as the coax splitter. Hmmm.
@16:05 4x 5086-7402 sampler assembly $100 ebay (part of quad mixer)
@21:00 HP 50867231 VTO/Driver assembly $200 ebay
Those prices are for suckers. There is a whole unit for under $500 right now on ebay. They are not that rare. The REST of the system is what is expensive!
It is good the channel gets advanced. There is a lot of basic crap everywhere already. We need some decent science here!
Hi Shahriar, I got a 8510c with a 8516A test set. I wish to add the option 001 (IF switch to connect others test set) because I was build millimetric setup and I wish to siwtch automatically. You have info about how works and if is possible to remove from a 8515 for example and add it to the 8516? my twitter is @eb3frn tnx!
I am curious about the specific difference in the built between 2 VNA bridge heads and these bulky couplers and sampling mixers. The actual mini VNAs from KS use a custom chip which integrate a coupler PI-network, 2 differential amplifiers and 2 downconversion mixer, driven from the same LO, converted to a relative low IF and then get digitized. The PI coupler, as the remaining components work from DC up the parasitic deorientation of the diffamp CMRR and the bridge cap load. Is there a reason for this built or simply squeeze IC tec this down up to 26GHz where the 80s 1Ghz was a an IC wall?
@Joel Dunsmore Thanks Joel. So IC technology is here indeed the main driver. The bridge with a typical 2/3 and 1/3 divider and 2 diffamps should be anyway significant smaller than a wavelenght. Where the directional couplers operation is based on size large to the wavelength. Mixer, ADC and processing profit obvious from IC tec.
Key point is: Wave direction could measured with a simple voltage divider.
this RF Stuff is total voodoo :D
Wondering who would that 1 person be who disliked this video?
The other bidder on the auction......
@@SeanBZA The person that sold the unit!
have used the same superb equipment back in the early 90's , it is a real jewel , very good to use , and today I bet associated with a digital scope with fast and deep memory would be still the best S parameter tool !! 100dollars for this is scandalous , but who knows what it is today of soft engineers ...
....
just sittin here waiting for youtube to convert twiddling my thumbs
There goes the second hand market for the s-parameter test set on eBay. Now the price is going to shot up sky high for the next 5 years.
Ha! First like.