[time-nuts] Phase noise measurement (was - no subject)

[Bob Camp]

Hi

I suspect you will have to hand wind the magnetics. 

The 5109 was still in production last time I shopped for them.

Bob



On Aug 21, 2010, at 1:52 PM, "Mark J. Blair" <nf6x at nf6x.net> wrote:

> 
> On Aug 20, 2010, at 11:17 AM, Rick Karlquist wrote:
>> The AMC-123 can also be homebrewed by reading the
>> patent, which is listed on the data sheet.
> 
> I found it here:
> 
> http://www.freepatentsonline.com/3624536.pdf
> 
> Having read the patent, I find I'm still weak enough in the area of discrete amplifier design that I'd have low confidence of creating an amplifier with the required phase noise, gain, isolation and compression specifications. Assuming the simple amplifier in Figure 1, I think I'm make or break the design (more likely the latter) by selecting a suitable in-production replacement for the 2N5109, figuring out the required turns ratio of autotransformer L1, biasing the transistor amplifier correctly, etc.
> 
> I'd have no problem building it; if I identified off-the-shelf magnetics then I could even build a whole bunch of them, as I design PCBs for a living (mostly GPS stuff; I can lay out the microwave stuff as long as a smart RF guy comes up with the necessary LNA circuit topology), and I even have a bit of experience designing mechanical stuff (i.e., in case it wanted to be in a nice machined aluminum shield/heat-sink box, though my CNC mill is presently in pieces so I'd need to farm out mechanical fabrication). I'm just weak in the analog/RF design area so far.
> 
> Since the "Q: Which amplifier? A: AMC-123!" thing appears to be a FAQ, and that patent may be old enough to have expired, I wonder if the world wants a nice plug-and-play TIME-NUTS-123 amplifier based on the Norton patent, designed with currently-available off-the-shelf components (aside from the custom PCB and possibly enclosure), which could be made in smallish batches, characterized by somebody with the right equipment, and sold at a reasonable price to help folks cobble together their home-brewed phase noise measurement and frequency reference distribution systems.
> 
> -- 
> Mark J. Blair, NF6X <nf6x at nf6x.net>
> Web page: http://www.nf6x.net/
> GnuPG public key available from my web page.
> 
> 
> 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>