[ARC5] Programmable Oscillators

[mstangelo at comcast.net]

If your experimenting with oscillators or replacing crystals in oscillators you may want use in a DDS oscillator such as WA1FFL's Direct Digital VFO based on the Analog Devices AD9951:

<http://www.wa1ffl.com/index.html>

The phase noise is much better than those microprocessor clock oscillators and they are tuneable.

I'd invest in one of these instead of purchasing crystals or single frequency crystal oscillators.

Mike N2MS

----- Original Message -----
From: Dennis Monticelli <dennis.monticelli at gmail.com>
To: David Stinson <arc5 at ix.netcom.com>
Cc: ARC-5 Maillist <arc5 at mailman.qth.net>
Sent: Wed, 13 Feb 2013 16:15:03 -0000 (UTC)
Subject: Re: [ARC5] Programmable Oscillators

Dave,

Keep in mind that these digital oscillators often have high phase noise in
addition to rich odd harmonics.  For harmonic filtering I would suggest a
simple two section LC low pass.  The output section of these oscillators
has a low Z so you can design the low pass for low Z terminations.
Unfortunately, there is nothing you can do about the phase except try to
buy those oscillators that have this noise specified or you know were
intended for a noise critical application.  For some of our uses the phase
noise won't be a big deal.  But if the oscillator is going to multiplied up
to VHF then the phase noise is going to rear its ugly head.

<snip>

Dennis AE6C


On Sun, Feb 10, 2013 at 7:50 AM, David Stinson <arc5 at ix.netcom.com> wrote:

> Here is a page from Digikey.  Lowest-price for through-hole
> oscillator, programmed to order by them is $4.10 in quantites of 1.
>
> <snip>
>
> 73 Dave AB5S.
>
>