[time-nuts] Frequency distribution isolation transformers YCL20F001n arrived
paulswedb at gmail.com
Sun Dec 14 13:41:34 EST 2014
Well with zero effort the spec sheet. Bob indeed there are common mode
chokes in them. Jeeze a lot in 1 package along with center taps.
On Sun, Dec 14, 2014 at 12:22 PM, Bob Camp <kb8tq at n1k.org> wrote:
> If you get the whole magnetics package (and not just a transformer) it
> probably will have a pretty good common mode choke in it. If you go back to
> the days of coax ethernet, the choke was more the “magic” that let them go
> to twisted pair than the transformer.
> Why does this matter?
> Well … we seem to still be stuck back in the “coax ethernet” era when it
> comes to standard distribution. Every time somebody brings up a need to go
> hundreds of feet, coax becomes a second choice sort of solution. That’s
> even more true for a pps. Don’t toss out the rest of the magnetics when you
> salvage one of these old beasts …
> Why mention pps? There are more than one isolated pair on those
> connectors. You would need to modulate the pps onto something at one end
> and demodulate it at the other end. There are a lot of cheap ways to do
> that, very much so if you are generating the pps yourself in something on
> the transmitting end.
> > On Dec 14, 2014, at 11:59 AM, Alan Melia <alan.melia at btinternet.com>
> > Hi Paul I confirm the 17MHz LPF response I didn't measure them for
> flatness :-)) The source I used was surplus 16way 10BaseT switches which
> were junked some time back but may still be lying in the back of store-room
> cupboards.....you get a lot on one board that way.
> > Alan
> > G3NYK
> > ----- Original Message ----- From: "paul swed" <paulswedb at gmail.com>
> > To: "Time-nuts" <time-nuts at febo.com>
> > Sent: Sunday, December 14, 2014 4:18 PM
> > Subject: [time-nuts] Frequency distribution isolation transformers
> YCL20F001n arrived
> >> Another Time-nut suggested the use of 10 baseT ethernet transformers
> for 10
> >> MHz isolation that he pulls from old ethernet boards. The 20F001n. These
> >> are available from UTSource on ebay at 90 cents each NOS. Ordered 20.
> >> Well I have to say as a BPF or something for 10 Mhz they are lousy. BUT
> >> then how could they be when they are a pretty flat transformer from 40
> >> to 17 MHz! Take that Mini-Circuits. (Only in jest) Yes there are some
> >> and bumps in that pass band But not large maybe 1-1.3db I need to get
> >> more accurate. But now I have a nice transformer that can work at WWVB
> >> Khz as well as with frequency distribution.
> >> They come in a dip foot print and 2 X to a package.
> >> I have more to check because to good to be true almost always is. At
> >> for me.
> >> Regards
> >> Paul
> >> WB8TSL
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