Lothar, ? Correct. The same thing happens with Zeners below 6.2V and TVS Diodes (way too much Capacitance for RF Applications). ? Look at the Breakover point of the RF Limiter (or TVS), it is a curve. Its Impedance changes below the breakover voltage as current flows through it and approaches the knee. If it is not specified, it can be obtained via a Curve Tracer or manually generated I-V Curves that you can produce with a simple Power Supply UUT and Resistance Standard or Resistance Decade. ? Many Signal Integrity issues develop when they are not used properly and the curve is well understood. ? Ross ?
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From: [email protected] < [email protected]> On Behalf Of Lothar baier Sent: Monday, March 21, 2022 2:28 PM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment ? What many people seem to forget is the fact that the non linear behavior of a limiter kicks in way before the limiter is actually ¡°triggered¡± ?although the distortions are not as bad ? ? Tom, ? That is also why MIL-STD-461 CE102 requires a 20dB Pad on the signal path from the LISN to the Receiver. They do not recommend a Limiter due to non-linearities that Lothar points out. ? Limiters can really hurt the Noise Figure of a receiver input at well. ? Ross ? ? Limiters are very commonly recommended for Conducted Immunity testing in EMC labs where the Spec An input comes from the Line Impedance Stabilization Network (LISN) because the turn on/off transients can be quite high. The levels expected to be measured typically should be much less than the distortion level of the limiter. The recommended limiter in this case actually has an intentional 10 dB insertion loss. ? ? ? A few words about limiters , Generally limiters are used in systems to protect receivers usually in RADAR or EW applications ,? in test systems the use of limiters s usually frowned upon ( with very few exceptions)? and for good reason ! First of there is a cost penalty that is not insignificant , the cost for a connectorized limiter usually starts at about $600 and can go up into the $2K range . Limiters also degrade VSWR and add additional system loss . But the by far biggest problem is that limiters are non linear devices and as such excellent harmonics generators , harmonics will start to occur before the limiter hits the hard threshold and worsens as the power increases so if you put one in front a spectrum analyzer you have to be cautious not to end up with tst results that are worse than they actually are ? ? Mini-Circuits sells limiters as well as DC blocks, but they only go up to 8 GHz.? Not sure about the price, but they are most likely competitive.? Assuming you actually need one. ------ Original Message ------ Sent: 3/20/2022 6:52:14 AM Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment It's worth adding that a DC block only provides some measure of safety. The ramp up voltage of a DC signal is an AC signal and can pass right through your series cap. If you look at DC blocking filter designs like the HP 3048A option K23, there's a limiter after the series cap. It seems like the "right" devices for this sort of thing are RF power limiters. Unfortunately, the cost of many of these devices new from reputable manufacturers probably matches or exceeds what many people paid for their second-hand spectrum analyzer. Maybe there are good second-hand market options, but I haven't looked into to it. If you want something to reliably protect a low frequency SA, that shouldn't be too hard to design and build. But, if you want to get the full 22 GHz range out of your 8566, I expect that wouldn't be so easy.
|
Tom, ? That¡¯s true except the most stringent limits for DC powered MIL-STD-461 CE-102 Conducted Emissions are much greater (94dBuV down to 60dBuV from 10kHz to 10MHz), than those of RE-102 Radiated Emissions (60dBuV to 24dBuV to 69dBuV from 10kHz to 18GHz). They also modify the CE-102 Limits for AC powered equipment by increasing the limit line by 6dB, 9dB, 10dB and 12dB based on Line Voltage too. ? The LISN Measurement Output Capacitor (such as the 0.25uF for the Standard MIL-STD-461 50uH LISN), is a High Pass Filter. MIL-STD-461 CE-102 starts at 10kHz, the LISN is designed for 10kHz to 10MHz. The Calibration Factors are all entered in the Program (like TILE!), you are using and added/subtracted from the measured value. ? Unless you are testing a poorly designed product or the Power Supply and the emissions are there because: 1. The Power Supply is operating in Discontinuous Conduction Mode (often seen as spaced emissions lower - 10s of kHz, than the switching frequency of the Power Supply). Happens in some types of Regulators and also when the Output Load is light. 2. The emissions are harmonics of the AC/DC Rectifiers Commutation from Bulk Capacitance Charging, ? After you check/fix the above issues, you should not see the need to add a limiter. ? ? If you have those issues, the power supply is suspect (grounding/PFC Circuitry/inadequate Bulk Capacitance/Type of Diodes, etc.), or a gross test setup issue (LISN Grounding/poor Cable Shield Termination/etc.), may be at fault. ? It could be that your Receiver is not powered through an Isolation Transformer to prevent an Alternate Return Path (Ground Loop), as well. This is especially true for measurements below 10kHz (like MIL-STD-461 CE-101 and others). ? Ross ?
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From: [email protected] < [email protected]> On Behalf Of n8zmTWH@... Sent: Monday, March 21, 2022 2:16 PM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment ? In my experience, non-military EMC, if the gadget you are testing can trigger the distortion of a limiter on a CE test, you are WAY above the limits you need to meet. It does make it harder to find the real offending frequencies, however. Then that 20 dB pad becomes beneficial as more than just a protective device.. ? Everything in front of the input screws up the noise figure; that¡¯s just physics. Unless it¡¯s a preamp, and then you have to watch for overload problems, much like the limiter effect. ? ? ? Tom, ? That is also why MIL-STD-461 CE102 requires a 20dB Pad on the signal path from the LISN to the Receiver. They do not recommend a Limiter due to non-linearities that Lothar points out. ? Limiters can really hurt the Noise Figure of a receiver input at well. ? Ross ? ? Limiters are very commonly recommended for Conducted Immunity testing in EMC labs where the Spec An input comes from the Line Impedance Stabilization Network (LISN) because the turn on/off transients can be quite high. The levels expected to be measured typically should be much less than the distortion level of the limiter. The recommended limiter in this case actually has an intentional 10 dB insertion loss. ? ? ? A few words about limiters , Generally limiters are used in systems to protect receivers usually in RADAR or EW applications ,? in test systems the use of limiters s usually frowned upon ( with very few exceptions)? and for good reason ! First of there is a cost penalty that is not insignificant , the cost for a connectorized limiter usually starts at about $600 and can go up into the $2K range . Limiters also degrade VSWR and add additional system loss . But the by far biggest problem is that limiters are non linear devices and as such excellent harmonics generators , harmonics will start to occur before the limiter hits the hard threshold and worsens as the power increases so if you put one in front a spectrum analyzer you have to be cautious not to end up with tst results that are worse than they actually are ? ? Mini-Circuits sells limiters as well as DC blocks, but they only go up to 8 GHz.? Not sure about the price, but they are most likely competitive.? Assuming you actually need one. ------ Original Message ------ Sent: 3/20/2022 6:52:14 AM Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment It's worth adding that a DC block only provides some measure of safety. The ramp up voltage of a DC signal is an AC signal and can pass right through your series cap. If you look at DC blocking filter designs like the HP 3048A option K23, there's a limiter after the series cap. It seems like the "right" devices for this sort of thing are RF power limiters. Unfortunately, the cost of many of these devices new from reputable manufacturers probably matches or exceeds what many people paid for their second-hand spectrum analyzer. Maybe there are good second-hand market options, but I haven't looked into to it. If you want something to reliably protect a low frequency SA, that shouldn't be too hard to design and build. But, if you want to get the full 22 GHz range out of your 8566, I expect that wouldn't be so easy.
|
What many people seem to forget is the fact that the non linear behavior of a limiter kicks in way before the limiter is actually ¡°triggered¡± ?although the distortions are not as bad
?
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From: [email protected] < [email protected]>
On Behalf Of si_emi_01 via groups.io
Sent: Monday, March 21, 2022 2:50 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment
?
Tom,
?
That is also why MIL-STD-461 CE102 requires a 20dB Pad on the signal path from the LISN to the Receiver. They do not recommend a Limiter due to non-linearities that Lothar points out.
?
Limiters can really hurt the Noise Figure of a receiver input at well.
?
Ross
?
?
Limiters are very commonly recommended for Conducted Immunity testing in EMC labs where the Spec An input comes from the Line Impedance Stabilization Network (LISN) because the
turn on/off transients can be quite high. The levels expected to be measured typically should be much less than the distortion level of the limiter. The recommended limiter in this case actually has an intentional 10 dB insertion loss.
?
?
?
A few words about limiters ,
Generally limiters are used in systems to protect receivers usually in RADAR or EW applications ,? in test systems the use of limiters s usually frowned upon ( with very few exceptions)? and for good reason !
First of there is a cost penalty that is not insignificant , the cost for a connectorized limiter usually starts at about $600 and can go up into the $2K range .
Limiters also degrade VSWR and add additional system loss .
But the by far biggest problem is that limiters are non linear devices and as such excellent harmonics generators , harmonics will start to occur before the limiter hits the hard threshold and worsens as the power increases so if you put
one in front a spectrum analyzer you have to be cautious not to end up with tst results that are worse than they actually are
?
?
Mini-Circuits sells limiters as well as DC blocks, but they only go up to 8 GHz.? Not sure about the price, but they are most likely competitive.? Assuming you actually need
one.
------ Original Message ------
Sent: 3/20/2022 6:52:14 AM
Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment
It's worth adding that a DC block only provides some measure of safety. The ramp up voltage of a DC signal is an AC signal and can pass right through your series cap. If you
look at DC blocking filter designs like the HP 3048A option K23, there's a limiter after the series cap. It seems like the "right" devices for this sort of thing are RF power limiters. Unfortunately, the cost of many of these devices new from reputable manufacturers
probably matches or exceeds what many people paid for their second-hand spectrum analyzer. Maybe there are good second-hand market options, but I haven't looked into to it. If you want something to reliably protect a low frequency SA, that shouldn't be too
hard to design and build. But, if you want to get the full 22 GHz range out of your 8566, I expect that wouldn't be so easy.
|
Re: Question about MMIC amp design for HP 8601a output replacement
In real life there are 2 ways to skin this cat ,? we either use conical inductors (piconics or coilcraft ) , wideband chokes ( great to 6GHz but on the low end only good to 10MHz )? or a series of smaller valued inductors !
What model # are you trying to use ?? what is the Gain and P1Db you need to get to ??
If you provide the info I be more than happy to run some simulations in MWO and give you a recommendation of parts to use
?
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From: [email protected] < [email protected]>
On Behalf Of DB via groups.io
Sent: Monday, March 21, 2022 2:58 PM
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] Question about MMIC amp design for HP 8601a output replacement
?
Hi,
I've read that it may be possible to use a MMIC amp to replace the failed hybrid output amps in the HP 8601a sweep generator.? I have some MiniCircuits GALI MMIC amps and wanted to try one of these.?
I am using AppCAD for the design calcs for blocking caps but have a question about the RF choke that is in series with the 200 ohm resistor on the bias power lead.
The MiniCircuits data says the impedance of the choke should be ~500ohms at the minimum operating freq (which is 100khz for the HP 8601a).? This is giving me a value of 795uH for 500ohm impedance.
The other limitation for the choke is the SRF self resonant freq.? The chokes that I'm finding in the 795uH range all seem to have SRF much lower than the max 110Mhz freq of the 8601a.? (most of the 800uH chokes I've found have SRF around 20-50Mhz).
I would appreciate any assistance on selecting the proper choke value that will be adequate for 100khz to 110Mhz.
Thanks
DB
|
In my experience, non-military EMC, if the gadget you are testing can trigger the distortion of a limiter on a CE test, you are WAY above the limits you need to meet. It does make it harder to find the real offending frequencies, however. Then that 20 dB pad becomes beneficial as more than just a protective device.. ? Everything in front of the input screws up the noise figure; that¡¯s just physics. Unless it¡¯s a preamp, and then you have to watch for overload problems, much like the limiter effect. ? ?
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From: [email protected] <[email protected]> On Behalf Of si_emi_01
Sent: Monday, March 21, 2022 3:50 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment? Tom, ? That is also why MIL-STD-461 CE102 requires a 20dB Pad on the signal path from the LISN to the Receiver. They do not recommend a Limiter due to non-linearities that Lothar points out. ? Limiters can really hurt the Noise Figure of a receiver input at well. ? Ross ? ? Limiters are very commonly recommended for Conducted Immunity testing in EMC labs where the Spec An input comes from the Line Impedance Stabilization Network (LISN) because the turn on/off transients can be quite high. The levels expected to be measured typically should be much less than the distortion level of the limiter. The recommended limiter in this case actually has an intentional 10 dB insertion loss. ? ? ? A few words about limiters , Generally limiters are used in systems to protect receivers usually in RADAR or EW applications ,? in test systems the use of limiters s usually frowned upon ( with very few exceptions)? and for good reason ! First of there is a cost penalty that is not insignificant , the cost for a connectorized limiter usually starts at about $600 and can go up into the $2K range . Limiters also degrade VSWR and add additional system loss . But the by far biggest problem is that limiters are non linear devices and as such excellent harmonics generators , harmonics will start to occur before the limiter hits the hard threshold and worsens as the power increases so if you put one in front a spectrum analyzer you have to be cautious not to end up with tst results that are worse than they actually are ? ? Mini-Circuits sells limiters as well as DC blocks, but they only go up to 8 GHz.? Not sure about the price, but they are most likely competitive.? Assuming you actually need one. ------ Original Message ------ Sent: 3/20/2022 6:52:14 AM Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment It's worth adding that a DC block only provides some measure of safety. The ramp up voltage of a DC signal is an AC signal and can pass right through your series cap. If you look at DC blocking filter designs like the HP 3048A option K23, there's a limiter after the series cap. It seems like the "right" devices for this sort of thing are RF power limiters. Unfortunately, the cost of many of these devices new from reputable manufacturers probably matches or exceeds what many people paid for their second-hand spectrum analyzer. Maybe there are good second-hand market options, but I haven't looked into to it. If you want something to reliably protect a low frequency SA, that shouldn't be too hard to design and build. But, if you want to get the full 22 GHz range out of your 8566, I expect that wouldn't be so easy.
|
Re: Question about MMIC amp design for HP 8601a output replacement
You may have to put several inductors in series.? Put the lowest value one closest to the amplifier.
Jim Ford?
Sent from my T-Mobile 4G LTE Device
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-------- Original message -------- From: "DB via groups.io" <CrDonMax1@...> Date: 3/21/22 12:58 PM (GMT-08:00) Subject: [HP-Agilent-Keysight-equipment] Question about MMIC amp design for HP 8601a output replacement
Hi, I've read that it may be possible to use a MMIC amp to replace the failed hybrid output amps in the HP 8601a sweep generator.? I have some MiniCircuits GALI MMIC amps and wanted to try one of these.? I am using AppCAD for the design calcs for blocking caps but have a question about the RF choke that is in series with the 200 ohm resistor on the bias power lead. The MiniCircuits data says the impedance of the choke should be ~500ohms at the minimum operating freq (which is 100khz for the HP 8601a).? This is giving me a value of 795uH for 500ohm impedance. The other limitation for the choke is the SRF self resonant freq.? The chokes that I'm finding in the 795uH range all seem to have SRF much lower than the max 110Mhz freq of the 8601a.? (most of the 800uH chokes I've found have SRF around 20-50Mhz). I would appreciate any assistance on selecting the proper choke value that will be adequate for 100khz to 110Mhz. Thanks DB
|
Question about MMIC amp design for HP 8601a output replacement
Hi,
I've read that it may be possible to use a MMIC amp to replace the failed hybrid output amps in the HP 8601a sweep generator.? I have some MiniCircuits GALI MMIC amps and wanted to try one of these.?
I am using AppCAD for the design calcs for blocking caps but have a question about the RF choke that is in series with the 200 ohm resistor on the bias power lead.
The MiniCircuits data says the impedance of the choke should be ~500ohms at the minimum operating freq (which is 100khz for the HP 8601a).? This is giving me a value of 795uH for 500ohm impedance.
The other limitation for the choke is the SRF self resonant freq.? The chokes that I'm finding in the 795uH range all seem to have SRF much lower than the max 110Mhz freq of the 8601a.? (most of the 800uH chokes I've found have SRF around 20-50Mhz).
I would appreciate any assistance on selecting the proper choke value that will be adequate for 100khz to 110Mhz.
Thanks
DB
|
Tom, ? That is also why MIL-STD-461 CE102 requires a 20dB Pad on the signal path from the LISN to the Receiver. They do not recommend a Limiter due to non-linearities that Lothar points out. ? Limiters can really hurt the Noise Figure of a receiver input at well. ? Ross ?
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From: [email protected] < [email protected]> On Behalf Of n8zmTWH@... Sent: Sunday, March 20, 2022 7:22 PM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment ? Limiters are very commonly recommended for Conducted Immunity testing in EMC labs where the Spec An input comes from the Line Impedance Stabilization Network (LISN) because the turn on/off transients can be quite high. The levels expected to be measured typically should be much less than the distortion level of the limiter. The recommended limiter in this case actually has an intentional 10 dB insertion loss. ? ? ? A few words about limiters , Generally limiters are used in systems to protect receivers usually in RADAR or EW applications ,? in test systems the use of limiters s usually frowned upon ( with very few exceptions)? and for good reason ! First of there is a cost penalty that is not insignificant , the cost for a connectorized limiter usually starts at about $600 and can go up into the $2K range . Limiters also degrade VSWR and add additional system loss . But the by far biggest problem is that limiters are non linear devices and as such excellent harmonics generators , harmonics will start to occur before the limiter hits the hard threshold and worsens as the power increases so if you put one in front a spectrum analyzer you have to be cautious not to end up with tst results that are worse than they actually are ? ? Mini-Circuits sells limiters as well as DC blocks, but they only go up to 8 GHz.? Not sure about the price, but they are most likely competitive.? Assuming you actually need one. ------ Original Message ------ Sent: 3/20/2022 6:52:14 AM Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment It's worth adding that a DC block only provides some measure of safety. The ramp up voltage of a DC signal is an AC signal and can pass right through your series cap. If you look at DC blocking filter designs like the HP 3048A option K23, there's a limiter after the series cap. It seems like the "right" devices for this sort of thing are RF power limiters. Unfortunately, the cost of many of these devices new from reputable manufacturers probably matches or exceeds what many people paid for their second-hand spectrum analyzer. Maybe there are good second-hand market options, but I haven't looked into to it. If you want something to reliably protect a low frequency SA, that shouldn't be too hard to design and build. But, if you want to get the full 22 GHz range out of your 8566, I expect that wouldn't be so easy.
|
8596E adjustment SAMPLING MATHC
I have a faulty 8596E, on page 42 the sampler match adjustment, I don't see the signal I should have when carrying out the procedure. I ask if the anomaly may reside in the sampling oscillator circuit, it reports the name of three signals, SD-RELDCK-SAMP5W-SAMPDRY, in this circuit I don't see any signal present, what should I look for?
|
First just because the source works with a 8515 doesn¡¯t mean its ok as the 8516 requires different source parameters as the 15 ,? generally no if found or phaselock error comes about if the source power is too low to generate a meaningful
IF signal from the reference samplers , for the 8516 the power into the testset must be between 0 and 10dBm for the 45MHz to 20GHz range and 10dBm for the 20-40GHz range , you mentioned that you have a flashing light on your source when the error occurs so
more than likely your source goes unleveled when you use the doubler !
?
?
?
This is the link to the service manual ,? check the unratioed and sampler test procedure to make sure your samplers are ok !
?
?
?
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From: [email protected] < [email protected]>
On Behalf Of Willy via groups.io
Sent: Sunday, March 20, 2022 6:04 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] 8516A cable question
?
07 APR 92 shows up on the right display of my 8340B, SN is 3050A. Is this new enough?
|
I made two of these to use with older
communications receivers. Power transformers in the day often
used paper that becomes acidic and crackely now that it's
seventy years old, National recivers are especially vulnerable.
I wonder if vacuum impregnating them with silicon oil or winding
varnish would help keep them from? developing the intra-winding
shorts they are so prone to. I can't recall ever seeing one of
them have an inter-winding short, an open winding, or a short to
ground.
?? Bruce Gentry, KA2IVY
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On 3/21/22 10:59, Roy J.
Tellason, Sr. wrote:
On Sunday 20 March 2022 02:02:21 pm greenboxmaven via groups.io wrote:
An older Uninterruptable Power Supply makes a very convenient way to
reduce line voltage. Find one of the old "loaf of bread" sized units
that uses the large 60 cycle transformer, rather than the newer ones
that use a switching inverter. Remove everything except the transformer,
fuse holder, outlets and switch. Use one half of the? primary winding
along with the 120 volt secondary to make an autotranformer. It will
drop 120 volts to about 109, which is much easier on older gear designed
for 110 or 115 volts.
???? Bruce Gentry, KA2IVY
Interesting! I happen to have a pile of those...
|
On Sunday 20 March 2022 02:02:21 pm greenboxmaven via groups.io wrote: An older Uninterruptable Power Supply makes a very convenient way to
reduce line voltage. Find one of the old "loaf of bread" sized units
that uses the large 60 cycle transformer, rather than the newer ones
that use a switching inverter. Remove everything except the transformer,
fuse holder, outlets and switch. Use one half of the? primary winding
along with the 120 volt secondary to make an autotranformer. It will
drop 120 volts to about 109, which is much easier on older gear designed
for 110 or 115 volts.
???? Bruce Gentry, KA2IVY Interesting! I happen to have a pile of those... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
|
Re: BS, was Re: [HP-Agilent-Keysight-equipment] Spread the word -- Swap Meet Returns!
On Monday 21 March 2022 01:41:19 am Michael A. Terrell wrote: My first real soldering tool was a Weller 8200 soldering gun , I still have (and occasionally use) one of those. in its carry case. They had a carry case? Never saw one of those... (snip) I used 99.5% tin, .5% antimony solder. I just acquired a roll of that stuff. I'm not sure what I'm gonna do with it... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
|
Re: Agilent 3458A Troubleshooting
Hi George,
Well the good news is that it is something basic rather than something (as yet) complicated.... :)
Another vote here for xDevs site & EEVblog?forum threads. I assume you've done a complete check for power & toasted components. Double check that everything is plugged in where it should be (say, by comparison with say xDevs images) - and that all the cables and sockets seem good. Particularly those to the digital board and display (and check the display voltage too) - it sounds like it's not even starting its boot sequence properly.
If not socketed already, I agree with your intuition, and would desolder, read and then socket the Dallas rams and ROMs. Compare ROMs against known good and also see if you can get any data out of the Dallas rams - I would think you have more than a 50/50 chance. You may want to change the electrolytics while you're there - a list is on my site:?
You don't say much about the provenance - maybe there isn't any, but maybe you can get a few clues? Re: 'but someone has maintained over the years' - hmmm, I think I might take all the boards out and give both sides a good look under a magnifier to see if you can see whether any detail work has been done already. Great care with fingerprint contamination of the analogue board of course. A swap with a known good digital board would be a helpful and quick diagnosis aid if you can borrow one. All the manuals, including schematics, are out there as pdfs, of course.
Ah, you're in Sydney! - I think there's a good chance EEVblog Dave could help a lot in person :) From (hazy) memory I think he has a 3458a or two to compare with / test against.
Alan
|
Re: BS, was Re: [HP-Agilent-Keysight-equipment] Spread the word -- Swap Meet Returns!
While I am younger, I also used a wood burning tool for soldering a few times.? My soldering iron had been taken away as punishment for something (I no longer recall), and I had a project I wanted to finish...? it didn't have a proper tinned tip, of course, but worked well and became my backup iron.? I still don't understand the appeal of charring wood!
-Dave
On Sunday, March 20, 2022, 09:57:23 PM PDT, John kolb <jlkolb@...> wrote:
Young punk kids :)? In 1957 I was soldering using the tool from my wood
burning set.
John? 1942
On 3/20/2022 8:33 AM, John Griessen wrote:
>
> On 3/20/22 04:51, Paul Bicknell wrote:
>> Hi
>> wasn't the EE20 the ad on set with speaker and a lot more components
>> wish I still had it as it was an inspiration for lots my age into
>> electronics
>
> I had one of the beginner sets from Philips also when I was 7 or 8 in
> Beaumont Texas.? I'm 1957 vintage also.
>
>
>
>
>
>
|
Re: BS, was Re: [HP-Agilent-Keysight-equipment] Spread the word -- Swap Meet Returns!
My first real soldering tool was a Weller 8200 soldering gun , in its carry case. I bought it before I turned 13 to repair raids and TVs in the mid '60s. I had a wood burner but the tips were too big to use on most electronics because you would burn wires. It was followed by an ENDEVCO desoldering iron a few months later. I still have the gun. I next bought a Weller SP23, and a SP175 to solder the mounting rings of tube sockets to a brass chassis for an RF amp. Since then I've used many other irons, and an oxyacetylene torch to solder the 3" copper pipes in an RCA TV transmitter. Some idiot tried to fix a leak by brazing the pipe to the brass fittings. I had fun fixing that, since they were custom made and nearly 40 years old. I used 99.5% tin, .5% antimony solder. I tinned the ends of the pipe and inside the brass first, to ensure no leaks. That solder had a mirror finish. :)
I couldn't get spare tips for the SP23 while stationed in Alaska, so I asked the Base engineers for some scrap welding rod and to borrow a die and the handle to thread it. A very large pair of dykes gave a decent chisel tip. That was almost 50 years ago and I still have a couple of those tips. Solder doesn't eat brass like it does pure copper.
On Mon, Mar 21, 2022 at 12:57 AM John kolb < jlkolb@...> wrote:
Young punk kids :)? In 1957 I was soldering using the tool from my wood
burning set.
John? 1942
On 3/20/2022 8:33 AM, John Griessen wrote:
>
> On 3/20/22 04:51, Paul Bicknell wrote:
>> Hi
>> wasn't the EE20 the ad on set with speaker and a lot more components
>> wish I still had it as it was an inspiration for lots my age into
>> electronics
>
> I had one of the beginner sets from Philips also when I was 7 or 8 in
> Beaumont Texas.? I'm 1957 vintage also.
>
>
>
>
>
>
|
Re: BS, was Re: [HP-Agilent-Keysight-equipment] Spread the word -- Swap Meet Returns!
Young punk kids :) In 1957 I was soldering using the tool from my wood burning set.
John 1942
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On 3/20/2022 8:33 AM, John Griessen wrote: On 3/20/22 04:51, Paul Bicknell wrote:
Hi
wasn't the EE20 the ad on set with speaker and a lot more components
wish I still had it as it was an inspiration for lots my age into electronics I had one of the beginner sets from Philips also when I was 7 or 8 in Beaumont Texas.? I'm 1957 vintage also.
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Yes, they are because the inductors in the LISN can generate some nasty spikes when device power is cycled. ? Most conducted EMC specs cut off at 30 MHz, or at least did up to the last time I worked in that area about 10 years ago. ? ?
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From: [email protected] <[email protected]> On Behalf Of Lothar baier
Sent: Sunday, March 20, 2022 10:14 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment? Those are transient limiters that are especially designed for this purpose , usually they only cover to 30 or 100MHz t match the frequency range of the LISN ( I only have seen the ones made by ETS that went to 100MHz not sure if they make higher frequency ones ) As far as the limiter itself concerns usually one attenuator of 3Db is used on the input followed by a diode limiter which is followed by another attenuator and then another ?limiter . ? ? ? Limiters are very commonly recommended for Conducted Immunity testing in EMC labs where the Spec An input comes from the Line Impedance Stabilization Network (LISN) because the turn on/off transients can be quite high. The levels expected to be measured typically should be much less than the distortion level of the limiter. The recommended limiter in this case actually has an intentional 10 dB insertion loss. ? ? ? A few words about limiters , Generally limiters are used in systems to protect receivers usually in RADAR or EW applications ,? in test systems the use of limiters s usually frowned upon ( with very few exceptions)? and for good reason ! First of there is a cost penalty that is not insignificant , the cost for a connectorized limiter usually starts at about $600 and can go up into the $2K range . Limiters also degrade VSWR and add additional system loss . But the by far biggest problem is that limiters are non linear devices and as such excellent harmonics generators , harmonics will start to occur before the limiter hits the hard threshold and worsens as the power increases so if you put one in front a spectrum analyzer you have to be cautious not to end up with tst results that are worse than they actually are ? ? Mini-Circuits sells limiters as well as DC blocks, but they only go up to 8 GHz.? Not sure about the price, but they are most likely competitive.? Assuming you actually need one. ------ Original Message ------ Sent: 3/20/2022 6:52:14 AM Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment It's worth adding that a DC block only provides some measure of safety. The ramp up voltage of a DC signal is an AC signal and can pass right through your series cap. If you look at DC blocking filter designs like the HP 3048A option K23, there's a limiter after the series cap. It seems like the "right" devices for this sort of thing are RF power limiters. Unfortunately, the cost of many of these devices new from reputable manufacturers probably matches or exceeds what many people paid for their second-hand spectrum analyzer. Maybe there are good second-hand market options, but I haven't looked into to it. If you want something to reliably protect a low frequency SA, that shouldn't be too hard to design and build. But, if you want to get the full 22 GHz range out of your 8566, I expect that wouldn't be so easy.
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Re: Youtube video HP service center in the 90th
If you look at the bottom edge of the video, it shows a timing error that flashes in time with the vertical jitter.
Amazing how the video bounces up/down in time with the music! Almost as
if it was supposed to do that.
Regards.
???? Dave B.
--
Created on and sent from a Unix like PC running and using free and open source software:
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Those are transient limiters that are especially designed for this purpose , usually they only cover to 30 or 100MHz t match the frequency range of the LISN ( I only have seen the ones made by ETS that went to 100MHz not sure if they make
higher frequency ones )
As far as the limiter itself concerns usually one attenuator of 3Db is used on the input followed by a diode limiter which is followed by another attenuator and then another ?limiter .
?
?
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Show quoted text
From: [email protected] < [email protected]>
On Behalf Of n8zmTWH via groups.io
Sent: Sunday, March 20, 2022 8:22 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment
?
Limiters are very commonly recommended for Conducted Immunity testing in EMC labs where the Spec An input comes from the Line Impedance Stabilization Network (LISN) because the
turn on/off transients can be quite high. The levels expected to be measured typically should be much less than the distortion level of the limiter. The recommended limiter in this case actually has an intentional 10 dB insertion loss.
?
?
?
A few words about limiters ,
Generally limiters are used in systems to protect receivers usually in RADAR or EW applications ,? in test systems the use of limiters s usually frowned upon ( with very few exceptions)? and for good reason !
First of there is a cost penalty that is not insignificant , the cost for a connectorized limiter usually starts at about $600 and can go up into the $2K range .
Limiters also degrade VSWR and add additional system loss .
But the by far biggest problem is that limiters are non linear devices and as such excellent harmonics generators , harmonics will start to occur before the limiter hits the hard threshold and worsens as the power increases so if you put
one in front a spectrum analyzer you have to be cautious not to end up with tst results that are worse than they actually are
?
?
Mini-Circuits sells limiters as well as DC blocks, but they only go up to 8 GHz.? Not sure about the price, but they are most likely competitive.? Assuming you actually need
one.
------ Original Message ------
Sent: 3/20/2022 6:52:14 AM
Subject: Re: [HP-Agilent-Keysight-equipment] Protecting Equipment
It's worth adding that a DC block only provides some measure of safety. The ramp up voltage of a DC signal is an AC signal and can pass right through your series cap. If you
look at DC blocking filter designs like the HP 3048A option K23, there's a limiter after the series cap. It seems like the "right" devices for this sort of thing are RF power limiters. Unfortunately, the cost of many of these devices new from reputable manufacturers
probably matches or exceeds what many people paid for their second-hand spectrum analyzer. Maybe there are good second-hand market options, but I haven't looked into to it. If you want something to reliably protect a low frequency SA, that shouldn't be too
hard to design and build. But, if you want to get the full 22 GHz range out of your 8566, I expect that wouldn't be so easy.
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Michael A. Terrell