Locked Service Monitor - Testing and Validation

Paul Guido

Here a test of the equipment to generate and count frequencies with accuracy.

On the far left is the GPS disciplined oscillator that is connected to the frequency generator and the frequency counter.  

The frequency generator is set to 999.900 MHz and the frequency counter is reading  within 0.083 Hz of that frequency.  More then close enough for my hobby.

Scott Carlyon KD5TJJ

Paul --
Thanks for a great presentation!  Very interesting.
Would you mind sharing a list the equipment you used in the photo above, including the make and model of each?
Also, what value attenuator are you using -- or is it variable?
My email is scott@... if you'd rather just send the info direct to me.
I'll appreciate it very much!

Paul Guido


Thank you, I am glad that it was well received.  

Most of it I got on eBay.  Buyer Beware.  Twice I ordered and they did not have the product in stock.  I insisted they refund the money and one took two weeks before they did.  Stay alert.

The following was from eBay

The GPSDO https://www.ebay.com/itm/165475429558
PLL-GPSDO GPS BG7TBL Tame Disciplined Clock Sine Wave GPS Receiver 10M 1PPS Green #US
From California

The place I bought the Signal Generator is sold out but here are two links from eBay.
1Hz-8GHz Wideband Signal Generator w/ Make-Break Modulation + Power Adapter - US


The Frequency Counter was out of China and took weeks to get here.
FA-3-6G Frequency Counter Meter 1Hz-6G 11Bit/Sec High-Precision FREQ COUNTER

I will most likely get a Distribution amplifier to send the signal to many systems from the same GPSDO.
10MHz Distribution amplifier OCXO frequency standard 8 port output

The person that made the riser card is on eBay as well.

Liquid Tin to coat the copper on the riser card from Amazon.

The last item that I did not discuss:
TL431 voltage reference board TL431 voltage source for calibrating multimeter. So if you would like to check your multimeter, this is a very good tool.
This is a very accuracy source voltage reference for ~2.5, 5 and 10 volts on one board and some high precision resistors and capacitors on another.  
I have tested the voltages to the hundreth of a volt and they were spot on with my Fluke 8060A down to the hundredth of a volt.  The resistances look to be very accurate as well. 
I do not have an accurate way to test capacitance.  

This is an ok attenuator to about 45db and it does the job I need.  I saw a review and the test results and it was not great.  It did not go to 60db as stated but I do not have a great way to test it.
I am sure it would help in a fox hunt.  
BECEN 60db SMA Push-Button Step attenuator,50 ohmKey-Press Attenuator,DC to 2.5GHz

One service monitor was a Wavetek CT Systems Model 2100 from 1989 and the other was a Motorola R-2200 A built in 1984.

Have a great day,

Paul, N5IUT

Scott Carlyon KD5TJJ

Thanks very much, Paul!