The spec sheet lists them as being good to 10MHz; would they be ok at 16MHz with a little more loss, or should I worry about resonances with parasitic capacitance?
73 de Henry M0HMH in Santa Cruz On Wed, Aug 4, 2010 at 9:14 PM, <[email protected]> wrote: > I think I'm a time-nut; as symptoms I include (1) a lot of Mini-Circuits > parts on my bench, (2) searches on eBay for Mini-Circuits goodies, and (3) > the desire to know how my LPRO, 10811, and Thunderbolt are different, and how > much better a Thunderbolt would be with a 10811 double-oven in it... > > Anyway, here's an eBay auction for 25 T-626 1:1:1 transformers -- item > number: 220544907085 > http://cgi.ebay.com/25-Mini-Circuits-T-626-RF-Transformers-0-01-10-MHz-/220544907085?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item335980374d > > which look like just the thing for this amp... > > 73 de bob k6rtm in silicon valley > > > ------------------------- > Message: 4 > Date: Thu, 05 Aug 2010 10:05:39 +1200 > From: Bruce Griffiths <[email protected]> > Subject: Re: [time-nuts] Buffer / distribution amplifier for TCXO > To: Discussion of precise time and frequency measurement > <[email protected]> > Message-ID: <[email protected]> > Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" > > Bruce Griffiths wrote: >> >> In which case a linear distribution amplifier is probably required. >> >> With only a ~3V supply available, options for the distribution >> amplifier topology are somewhat limited. >> In principle you could use an emitter follower driving 4 other emitter >> followers with a resistor in series with the emitters of the output >> devices and the AC coupled loads to match the source to the >> interconnecting cable impedance to minimise reflections without >> requiring excessive dissipation in the emitter followers. >> With the low voltage supply available, using an RF choke is series >> with the emitter follower's emitter to ground resistor will also be >> useful in achieving the required dynamic range. >> >> Bruce > > A more efficient buffer amplifier circuit schematic is attached. > > The series transformer feedback stage has high input impedance and an > output impedance matched to the transmission line (yes it works well > with long transmission lines as well). > However a trifilar wound RF transformer is required. > > In principle the various GPS receivers could be connected to taps along > an end terminated transmission line using feedthrough connections with > compensation for the tap shunt capacitance if necessary. > > A lower impedance line (eg 50 ohms) could also be driven at the expense > of a higher collector current. > In this case the value of R3 would need to be reduced to around 100 ohms > or so. > > Bruce > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: TCXO_BUFFER.gif > Type: image/gif > Size: 7990 bytes > Desc: not available > URL: > <http://www.febo.com/pipermail/time-nuts/attachments/20100805/091e6a74/attachment.gif> > > ------------------------------ > > _______________________________________________ > time-nuts mailing list > [email protected] > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > End of time-nuts Digest, Vol 73, Issue 12 > ***************************************** > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Henry Hallam Sent from my Laptop _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
