[time-nuts] RFTG-m-XO disassembly photos

[Rex]

On Tue, 26 Dec 2006 22:06:28 -0600, "Bill Hawkins" <bill at iaxs.net>
wrote:

>What's all this about 15 MHz out?
>
>Bill Hawkins

I have an FRS-C rubidium (10 MHz) that I bought a couple years ago. It
came in a metal box that also contained a circuit board that provided 3
TNC output connectors. Two of those had 10 MHz square wave output. One
provided a strong (24.3 dBm into 50 ohms) 15 MHz sine wave output.

The board somehow used the 10 MHz from the rubidium to generate a 15 MHz
sine. I never figured out exactly how they were doing this; the board
had an an Altera EP610PC-25T PLD doing most of the interesting stuff. I
now suspect my box must have been for a similar setup to the Lucent
application.

In the FRS box I noticed a 15 MHz filter on the board. If you look at
John's picture rftg-m-xo-7.jpg, the metal can in the top-center (not the
Efratom oscillator) is a 15 MHz filter.