# [time-nuts] Any simple way to get 200 MHz from 10 MHz?

dlewis dlewis6767 at austin.rr.com
Sun Sep 28 09:49:33 EDT 2014

```If you can use 90 MHz, .....

The A21- 90 MHz/10 MHz Board in an older HP3585A SA actually works quite
nicely in  'stand-alone' mode.   ( It brings lots of the 'glue' needed for
one of my analog GPSDOs.)

The schematic is readily available showing the HP 10 MHz-to-90 MHz
multiplier design.

I used this A21 board in a simple GPSDO along with an HP-10811 oscillator.
These pwbs are often available on eBay real cheap.

The board has ECL on it, so you have to supply some negative PS, ...but the
90 MHz multiplier is there, along with some lower frequency outputs (100
KHz), making it easier to interface to the 10 KHz -output from a GPS.

Don
KG5CID

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-----Original Message-----
From: Dr. David Kirkby (Kirkby Microwave Ltd)
Sent: Sunday, September 28, 2014 5:24 AM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Any simple way to get 200 MHz from 10 MHz?

I am looking for a quick & simple way to create a frequency of 200 MHz from
10 MHz.  Actually 100, 200, 300 or 400 MHz would all work,  but 200 MHz
would be my preference.

The input will be around 0 to +10 dBm and the output needs to be about +13
dBm.

I did think of a x5 & x4 frequency multipliers and amplifiers from
Minicircuits, but I don't know if the increase in phase noise might be a
problem.  The truth is I don't know how good it needs to be!

I am trying to find a way of building something that will allow my HP 8720D
VNA (50 MHz-20 GHz) to work below 50 MHz. My idea was to generate a 200 MHz
local oscillator to feed a mixer.
I was thinking of making it so as the VNA sweeps from 200.01-250 MHz, it
possible to analyse a DUT over the frequency range 0.01-50 MHz.

Having the  an integer multiple of 100 MHz is good, as it makes reading the
VNA easier. It is simpler to use if the VNA display shows the frequency 200
MHz off than if its 212.5564 MHz wrong.

I would rather not have to program anything to do it,  but maybe a VCO and
PLL is the only sensible approach.

I can't seem to find an off the shelf solution which I can lock to a 10 MHz
reference.  There are plenty of 200 MHz oscillators around based on a TCXO,
but I can't lock them to the 10 MHz oscillator the VNA uses.  Maybe someone
knows of a device I don't know of.

Dave.
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