Watkins-Johnson YIG Oscillator


Sean Breheny
Fri, 02 Oct 09 03:53:36 +0300
Hi all,

I recently bought a surplus microwave YIG oscillator made by
Watkins-Johnson. Model WJ6708-7DF. Date code 8521. 2-8GHz.
Unfortunately, I have no additional data on it. It uses a DB9 male
connector for all signals/power except for the SMA RF output. The
company I bought it from said that they do not have a datasheet. Does
anyone know where I might find at least a pinout?

Thanks,

Sean
2 replies folowing
Michael Rigby-Jones
Fri, 02 Oct 09 17:40:02 +0300


> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On

Behalf

> Of Sean Breheny
> Sent: 02 October 2009 01:54
> To: Microcontroller discussion list - Public.
> Subject: [EE] Watkins-Johnson YIG Oscillator
>
> Hi all,
>
> I recently bought a surplus microwave YIG oscillator made by
> Watkins-Johnson. Model WJ6708-7DF. Date code 8521. 2-8GHz.
> Unfortunately, I have no additional data on it. It uses a DB9 male
> connector for all signals/power except for the SMA RF output. The
> company I bought it from said that they do not have a datasheet. Does
> anyone know where I might find at least a pinout?
>
> Thanks,
>
> Sean


The Triquint website has a large number of technical documents from
Watkins-Johnson, though they are mostly very dark scans. Lots of stuff
on YIG tuned oscillators, so you might strike lucky.

http://www.triquint.com/prodserv/tech_info/WJ_tech_publications.cfm


A search through http://watkins-johnson.terryo.org/ may also yield
something.

Cheers

Mike

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Sean Breheny
Sat, 03 Oct 09 21:21:57 +0300
Thanks for your reply, Mike.

I looked at those sites but didn't find this model listed. I got some
help from a guy named John Miles who has a web site about microwave
experimentation. With his input, plus some reverse-engineering, I
finally got the device to work. Here is the pinout I was able to
determine:

1 - V tune +
2 - V tune -
3 - FM coil (polarity not yet determined - about 1 ohm resistance)
4 - FM coil
5 - +15V
6 - -5V
7 - Heater (using 22V just fine - drawing only about 20mA after warmup
of a few seconds)
8 - Heater
9 - Gnd

It seems that V tune + and V tune - are OK if isolated from ground,
and connecting V tune - to ground still works but alters the input
impedance of V tune + a bit.

I am getting oscillation when V tune is between 2.5V and 10V. Seems
like around 50 to 100K from V tune+ to V tune -.

The amplitude is fairly constant between about 7dBm and 10.5dBm.
Interestingly, the higher frequency end is higher amplitude, slightly.

I am puzzled, though, and a bit disappointed that I am only getting
output from 2.17 to 7 GHz (linear between 2.5V and 10V input). The
rating is 2 to 8 GHz on the top of the device. If anyone has any ideas
on what may be going on here, that would be great.

Sean



On Fri, Oct 2, 2009 at 10:40 AM, Michael Rigby-Jones
wrote:

>
>
>> -----Original Message-----
>> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On
> Behalf
>> Of Sean Breheny
>> Sent: 02 October 2009 01:54
>> To: Microcontroller discussion list - Public.
>> Subject: [EE] Watkins-Johnson YIG Oscillator
>>
>> Hi all,
>>
>> I recently bought a surplus microwave YIG oscillator made by
>> Watkins-Johnson. Model WJ6708-7DF. Date code 8521. 2-8GHz.
>> Unfortunately, I have no additional data on it. It uses a DB9 male
>> connector for all signals/power except for the SMA RF output. The
>> company I bought it from said that they do not have a datasheet. Does
>> anyone know where I might find at least a pinout?
>>
>> Thanks,
>>
>> Sean
>
> The Triquint website has a large number of technical documents from
> Watkins-Johnson, though they are mostly very dark scans. ´┐ŻLots of stuff
> on YIG tuned oscillators, so you might strike lucky.
>
> http://www.triquint.com/prodserv/tech_info/WJ_tech_publications.cfm
>
>
> A search through http://watkins-johnson.terryo.org/ may also yield
> something.
>
> Cheers
>
> Mike
>
> =======================================================================
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> information contained in it may be confidential and/or protected by
> law. If you are not the intended recipient of this message, you must
> not make any use of this information, or copy or show it to any
> person. Please contact us immediately to tell us that you have
> received this e-mail, and return the original to us. Any use,
> forwarding, printing or copying of this message is strictly prohibited.
> No part of this message can be considered a request for goods or
> services.
> =======================================================================
>
> --
> > > >