Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-22 Thread Magnus Danielson
Charles, On 05/12/2016 10:34 AM, Charles Steinmetz wrote: Bruce wrote: For even lower flicker noise using a mixer assembled using 2NA's as diodes is even quieter as NIST have shown. Note that mixers built with 2Ns only have lower noise than good schottky DBMs below about 200 Hz

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-12 Thread Bob Camp
>> OK, I can see that. I had been wondering about how to build it out, but it >> seems like each module should be on its own PCB for isolation. That keeps >> the costs down, except for the numerous SMA jumpers - and the eventual big >> box. >> >> Bob >

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-12 Thread Charles Steinmetz
Bruce wrote: >  For even lower flicker noise using a mixer assembled using > 2NA's as diodes is even quieter as NIST have shown. Note that mixers built with 2Ns only have lower noise than good schottky DBMs below about 200 Hz -- above that, schottky DBMs are better (see Figures 4 and

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-12 Thread Bob Camp
't the DDS spurs cancel out across the 2 DBMS? > > Bob > > On Wed, 5/11/16, Bruce Griffiths <bruce.griffi...@xtra.co.nz> wrote: > > Subject: Re: [time-nuts] DMTD was: high rev isolation amps > To: "Bob Stewart"

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-12 Thread Bob Camp
en wondering about how to build it out, but it > seems like each module should be on its own PCB for isolation. That keeps > the costs down, except for the numerous SMA jumpers - and the eventual big > box. > > Bob > > On Wed, 5/11/16, Bob Camp <kb...@n1k

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-12 Thread John Ackermann N8UR
wn, except for the numerous SMA jumpers - and the eventual big box. Bob On Wed, 5/11/16, Bob Camp <kb...@n1k.org> wrote: Subject: Re: [time-nuts] DMTD was: high rev isolation amps To: "Bob Stewart" <b...@evoria.net>, "Dis

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-12 Thread Attila Kinali
On Thu, 12 May 2016 05:51:50 + (UTC) Bruce Griffiths wrote: > The input noise of a 125 series gate will be far larger than the noise at the > mixer output at the beat frequency. A 125 may be useful as the output stage > of a Collins style limiter chain wherein

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-12 Thread Bruce Griffiths
ule should be on its own PCB for isolation.  That keeps the costs down, except for the numerous SMA jumpers - and the eventual big box. Bob On Wed, 5/11/16, Bob Camp <kb...@n1k.org> wrote: Subject: Re: [time-nuts] DMTD was: high rev isolat

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-12 Thread Bruce Griffiths
costs down, except for the numerous SMA jumpers - and the eventual big box. Bob On Wed, 5/11/16, Bob Camp <kb...@n1k.org> wrote: Subject: Re: [time-nuts] DMTD was: high rev isolation amps To: "Bob Stewart" <b...@evoria.net>, &

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-11 Thread Bob Stewart
olation.  That keeps the costs down, except for the numerous SMA jumpers - and the eventual big box. Bob On Wed, 5/11/16, Bob Camp <kb...@n1k.org> wrote: Subject: Re: [time-nuts] DMTD was: high rev isolation amps To: "Bob S

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-11 Thread Bruce Griffiths
its own PCB for isolation.  That keeps the costs down, except for the numerous SMA jumpers - and the eventual big box. Bob On Wed, 5/11/16, Bob Camp <kb...@n1k.org> wrote: Subject: Re: [time-nuts] DMTD was: high rev isolation amps To: "Bob St

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-11 Thread Bruce Griffiths
e-nuts] DMTD was: high rev isolation amps To: "Bob Stewart" <b...@evoria.net>, "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Date: Wednesday, May 11, 2016, 8:44 PM Hi For extra added “Time Nut” grade fun: Clip the collector lead o

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-11 Thread Bob Camp
Hi For extra added “Time Nut” grade fun: Clip the collector lead off of the SOT-223 packages (between emitter and base leads). You probably will gain a couple of db of isolation. (running common base). Bob > On May 11, 2016, at 8:24 PM, Bob Stewart wrote: > > Hi Bob et al,

Re: [time-nuts] DMTD was: high rev isolation amps

2016-05-11 Thread Bob Stewart
, 5/11/16, Bob Camp <kb...@n1k.org> wrote: Subject: Re: [time-nuts] DMTD was: high rev isolation amps To: "Bob Stewart" <b...@evoria.net>, "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Date: Wednesday, May 11, 2016, 8:44 PM

[time-nuts] DMTD was: high rev isolation amps

2016-05-11 Thread Bob Stewart
Hi Bob et al, I'm finally drawing up a schematic for a DMTD and I thought I'd use the NBS circuits for a lot of it. So, how about PZT3904 transistors in the isolation amps? They're in SOT-223 with the heat sink tab. I figure to use some version of the TUF-1 for the DBMs. The first version