# [time-nuts] locking oscillators - an increase in power and/or stability ?

Dave Brown tractorb at ihug.co.nz
Wed Oct 8 21:56:44 UTC 2014

```What about impedance matching?
Will a magic tee output with two gunn sources driving it will look anything
like a single source -as far as the power measuring device is concerned?
And similarly -impedance wise- what will the inputs to the magic tee look
like compared to the power measurig device being directly connected to each
of the sources? I suspect there will be source impedance changes- depending
on the sources being injection locked or not- as well.
But its been quite a while since I worked with this stuff.........

DaveB, NZ

----- Original Message -----
From: "Dr. David Kirkby (Kirkby Microwave Ltd)"
<drkirkby at kirkbymicrowave.co.uk>
To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
Sent: Thursday, October 09, 2014 9:46 AM
Subject: Re: [time-nuts] locking oscillators - an increase in power and/or
stability ?

> On 8 Oct 2014 20:26, "Bob Camp" <kb8tq at n1k.org> wrote:
>>
>> Hi
>>
>> It’s called injection locking. The two oscillators (or what ever) lock up
> at exactly the same frequency and some arbitrary phase. Depending on the
> amplitude and phase at the sum point, the result can be anything from +6
> db
> to zero power. Anything that oscillates can injection lock if given the
> right feedback at the right point.
>>
>> The gotcha is that they are at the same frequency, so they add as
> voltages rather than power. In phase, equal amplitude, you get 6 db more
> power. Exactly 180 degrees out of phase and exactly equal power and you
> get
> nothing (no power at all) at the sum point. Off by a fraction of a degree
> or a fraction of a db and you still get roughly 6 db in the zero degree
> case.
>
> But while voltages could double,  that is not going to happen if something
> limits the current.
>
>> Bob
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