Feedthrough caps have gotten stupid expensive, like $15 per pin. There are D sub connectors with built-in capacitance of up to about 47 nF, and I seem to recall seeing ferrite plates whose holes matched the D-sub pattern, but can't find them. A 9-pin one would be great. What do you folks use for EMI filtering on connectors? Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Filter connectors
Started by ●January 5, 2022
Reply by ●January 5, 20222022-01-05
onsdag den 5. januar 2022 kl. 20.43.48 UTC+1 skrev Phil Hobbs:> Feedthrough caps have gotten stupid expensive, like $15 per pin.https://www.surplussales.com/FEEDTHRUS/FTHOLEMNT3.HTML ? https://www.alibaba.com/product-detail/M3-1000PF-Feedthrough-Capacitor_60409523377.html https://de.aliexpress.com/item/1542421201.html>There > are D sub connectors with built-in capacitance of up to about 47 nF, and > > I seem to recall seeing ferrite plates whose holes matched the D-sub > pattern, but can't find them. A 9-pin one would be great.https://www.digikey.at/en/products/detail/fair-rite-products-corp/2644236101/8593849 ?
Reply by ●January 5, 20222022-01-05
On Wed, 5 Jan 2022 14:43:36 -0500, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>Feedthrough caps have gotten stupid expensive, like $15 per pin. There >are D sub connectors with built-in capacitance of up to about 47 nF, and > >I seem to recall seeing ferrite plates whose holes matched the D-sub >pattern, but can't find them. A 9-pin one would be great.Hi, Phil:- Fair-Rite 2644236101 looks like what you want. Laird also may have something.> >What do you folks use for EMI filtering on connectors?Feedthrough PI filters are very expensive but work nicely. You can get military style connectors with some filtering built in, not cheap.>Cheers > >Phil Hobbs-- Best regards, Spehro Pefhany
Reply by ●January 5, 20222022-01-05
On Wed, 05 Jan 2022 15:23:40 -0500, Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> wrote:>On Wed, 5 Jan 2022 14:43:36 -0500, Phil Hobbs ><pcdhSpamMeSenseless@electrooptical.net> wrote: > >>Feedthrough caps have gotten stupid expensive, like $15 per pin. There >>are D sub connectors with built-in capacitance of up to about 47 nF, and >> >>I seem to recall seeing ferrite plates whose holes matched the D-sub >>pattern, but can't find them. A 9-pin one would be great. > >Hi, Phil:- > >Fair-Rite 2644236101 looks like what you want. Laird also may have >something. >> >>What do you folks use for EMI filtering on connectors? > >Feedthrough PI filters are very expensive but work nicely. > >You can get military style connectors with some filtering built in, >not cheap. > >>Cheers >> >>Phil HobbsThere are gender-changer-looking sorts of filter things that plug into a d-sub. -- If a man will begin with certainties, he shall end with doubts, but if he will be content to begin with doubts he shall end in certainties. Francis Bacon
Reply by ●January 5, 20222022-01-05
Am 05.01.22 um 20:43 schrieb Phil Hobbs:> Feedthrough caps have gotten stupid expensive, like $15 per pin. There > are D sub connectors with built-in capacitance of up to about 47 nF, and > > I seem to recall seeing ferrite plates whose holes matched the D-sub > pattern, but can't find them. A 9-pin one would be great. > > What do you folks use for EMI filtering on connectors?< https://www.digikey.de/de/products/detail/tusonix-a-subsidiary-of-cts-electronic-components/2499-003-X5W0-502PLF/3116039 > I have bought this one 1.5 years ago for € 6. I found that not exactly cheap for a ~M4 bolt with a tube capacitor inside. Now it is € 21. But it was €27 2 weeks ago when a customer wanted to buy them for the series. :-( I'm looking myself for something smaller and cheaper. cheers, Gerhard
Reply by ●January 5, 20222022-01-05
Gerhard Hoffmann wrote:> Am 05.01.22 um 20:43 schrieb Phil Hobbs: >> Feedthrough caps have gotten stupid expensive, like $15 per pin. >> There are D sub connectors with built-in capacitance of up to about 47 >> nF, and >> >> I seem to recall seeing ferrite plates whose holes matched the D-sub >> pattern, but can't find them. A 9-pin one would be great. >> >> What do you folks use for EMI filtering on connectors? > > > < > https://www.digikey.de/de/products/detail/tusonix-a-subsidiary-of-cts-electronic-components/2499-003-X5W0-502PLF/3116039 > > > > I have bought this one 1.5 years ago for € 6. > I found that not exactly cheap for a ~M4 bolt with a > tube capacitor inside. > > Now it is € 21. But it was €27 2 weeks ago when a customer > wanted to buy them for the series. :-( > > I'm looking myself for something smaller and cheaper. > > cheers, GerhardThanks, all, that Fair-Rite part was what I was thinking of. Forty cents for 9 isolators is about the right price. Turns out that Tusonix sells some pretty nice solder-in and threaded feedthroughs for a buck or so--see RF-microwave.com. Cheers Phil -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●January 5, 20222022-01-05
On Wed, 5 Jan 2022 18:21:29 -0500, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>Gerhard Hoffmann wrote: >> Am 05.01.22 um 20:43 schrieb Phil Hobbs: >>> Feedthrough caps have gotten stupid expensive, like $15 per pin. >>> There are D sub connectors with built-in capacitance of up to about 47 >>> nF, and >>> >>> I seem to recall seeing ferrite plates whose holes matched the D-sub >>> pattern, but can't find them.� A 9-pin one would be great. >>> >>> What do you folks use for EMI filtering on connectors? >> >> >> < >> https://www.digikey.de/de/products/detail/tusonix-a-subsidiary-of-cts-electronic-components/2499-003-X5W0-502PLF/3116039 >> � > >> >> I have bought this one 1.5 years ago for � 6. >> I found that not exactly cheap for a ~M4 bolt with a >> tube capacitor inside. >> >> Now it is � 21. But it was �27 2 weeks ago when a customer >> wanted to buy them for the series.� :-( >> >> I'm looking myself for something smaller and cheaper. >> >> cheers, Gerhard > >Thanks, all, that Fair-Rite part was what I was thinking of. Forty >cents for 9 isolators is about the right price. > >Turns out that Tusonix sells some pretty nice solder-in and threaded >feedthroughs for a buck or so--see RF-microwave.com. > >Cheers > >PhilSo many RF boxes use these things for power input. You have to solder a wire outside onto the feedthru or something awkward like that. It's barbaric. Even tubes plugged into sockets. -- If a man will begin with certainties, he shall end with doubts, but if he will be content to begin with doubts he shall end in certainties. Francis Bacon
Reply by ●January 6, 20222022-01-06
John Larkin wrote:> On Wed, 5 Jan 2022 18:21:29 -0500, Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote: > >> Gerhard Hoffmann wrote: >>> Am 05.01.22 um 20:43 schrieb Phil Hobbs: >>>> Feedthrough caps have gotten stupid expensive, like $15 per pin. >>>> There are D sub connectors with built-in capacitance of up to about 47 >>>> nF, and >>>> >>>> I seem to recall seeing ferrite plates whose holes matched the D-sub >>>> pattern, but can't find them. A 9-pin one would be great. >>>> >>>> What do you folks use for EMI filtering on connectors? >>> >>> >>> < >>> https://www.digikey.de/de/products/detail/tusonix-a-subsidiary-of-cts-electronic-components/2499-003-X5W0-502PLF/3116039 >>> > >>> >>> I have bought this one 1.5 years ago for € 6. >>> I found that not exactly cheap for a ~M4 bolt with a >>> tube capacitor inside. >>> >>> Now it is € 21. But it was €27 2 weeks ago when a customer >>> wanted to buy them for the series. :-( >>> >>> I'm looking myself for something smaller and cheaper. >>> >>> cheers, Gerhard >> >> Thanks, all, that Fair-Rite part was what I was thinking of. Forty >> cents for 9 isolators is about the right price. >> >> Turns out that Tusonix sells some pretty nice solder-in and threaded >> feedthroughs for a buck or so--see RF-microwave.com. >> > > So many RF boxes use these things for power input. You have to solder > a wire outside onto the feedthru or something awkward like that. It's > barbaric. Even tubes plugged into sockets.I hear you. But we do a lot of proof-of-concept demos for licensed design-in solutions. Having stuff on the shelf that we can bolt together with no signal integrity worries is a huge win. Once they get onto the customer's board, the signal integrity worries are much less serious--cap multipliers and board-level shields are better than good enough. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●January 10, 20222022-01-10
On 06/01/2022 07:23, Spehro Pefhany wrote:> On Wed, 5 Jan 2022 14:43:36 -0500, Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote: > >> Feedthrough caps have gotten stupid expensive, like $15 per pin. There >> are D sub connectors with built-in capacitance of up to about 47 nF, and >> >> I seem to recall seeing ferrite plates whose holes matched the D-sub >> pattern, but can't find them. A 9-pin one would be great. > > Hi, Phil:- > > Fair-Rite 2644236101 looks like what you want. Laird also may have > something.They mention high resistivity, but I couldn't see how conductive that material is. Hopefully not very.
