Sunday, July 22, 2018

Open Source DIY Agilent 53132A 53131A 53181A OCXO Ultra High Stability Timebase Oven Upgrade

While i was working with my own GPSDO project. i need to have a frequency counter with descent stability so purchased my self a Agilent 53132A which is a 12 digit frequency counter , big brother to 53131A 10 Digit Counter. Both are really nice units.
But they unusable standard Timebase. So optional oven oscillator time base need to purchase. but 53132A and 53131A both unit are no longer available for sale. and neither of the Time base upgrades.

At first i decided to look around for time bases on online retail sites as already knew other people are selling them.
But i had few doubts , how well the whole thing is put together. what kind of parts they have used? How good is oven they are using? and Are they using same parts as per the original Agilent time base?
As it is quite normal for stuff listed on common online retail sites, It are quite cheaply made. and i found not even a single Time base who provides exact Bill of martial and give any specification details about the OCXO they are having. ofcourse OCXO is quite expensive so they all were using old OCXO which is totally fine but some data should be available.





Wednesday, July 18, 2018

TruePosition GPSDO 10Mhz Clock Standard Reference Distribution Board

As i am working on my own GPSDO project i had multiple of these Trueposition GPSDO modules, for using them correctly i put them into enclosure. here is how whole project goes.




Saturday, July 14, 2018

DIY Isolated 10Mhz Distribution Amplifier for GPSDO, Rubidium, TCXO Reference

while working on own GPS diciplined oscillator (GPSDO) project i needed few references so bought multiple of TruePosition GPSDO board form True Position LMU300 receiver unit. These Trueposition GPSDO are relly nice boards but they as usual only one single output, so made my self This little Distribution board to have up to 6 Isolated 10 Mhz sine wave output.

There is not many things in hardware but few LC filter to clean 10Mhz sine wave and few powerful opamp with isolation transformers to drive multiple 50Ohm load.


DIY Open Source 4.4Ghz RF Signal Generator AD4351 USB Cross Platform QT 5

A little while ago i was working a project for which i needed signal source in Ghz range , but my Arb Generator goes only upto 120Mhz. so i looked around a found many people having tiny little boards based on analog devices AD4351.

From AD4351 Datasheet

"The ADF4351 allows implementation of fractional-N or integer-N phase-locked loop (PLL) frequency synthesizers when used with an external loop filter and external reference frequency. The ADF4351 has an integrated voltage controlled oscillator (VCO) with a fundamental output frequency ranging from 2200 MHz to 4400 MHz. In addition, divide-by-1/-2/-4/-8/-16/-32/-64 circuits allow the user to generate RF output frequencies as low as 35 MHz. For applications that require isolation, the RF output stage can be muted. The mute function is both pin- and software-controllable. An auxiliary RF output is also available, which can be powered down when not in use. Control of all on-chip registers is through a simple 3-wire interface. The device operates with a power supply ranging from 3.0 V to 3.6 V and can be powered down when not in use  "

its basically a PLL which take a normal crystal oscillator frequency range of clock and can produce really high frequency in the range of 35 Mhz to 4.4 Ghz.

Hardware.




Hardware consist of a usb controller and AD4351 Board purchased off ebay .
I had made little USB board based on the PIC16F1459 , this board has nothing but a usb microcontroller , fuse and passives. this little board is part 3 of the USB IO boards i did in the past. More details  about this board are published in other post.