Microwave Frequency Standard Jim Hudson WA5JAT HamCom June 2010 WA5JAT
Microwave Frequency Standard Why Do we Need a Frequency Standard? Remember the 100 KHz Calibrators on HF? The Same Issues Exist on the Microwave Bands Uncertainty in Frequency (+/-100 KHz at 24 GHz) High Gain Antennas for Microwave Bands <3 Degree Beam Width Uncertain Rover Station Locations Too Many Things to Monitor: Antenna Elevation/Azimuth Frequency Dial + Readout “Hopefully”, Copy a CW Signal “In The Noise” Doing All These at Once is “Not Fun” Having a Precision Frequency Standard and Eliminating the Frequency Uncertainty is a BIG Help WA5JAT
Microwave Frequency Standard Surplus Equipment is Available!!! Rubidium Std RFG-M-RB Crystal Oscillator RFG-M-XO Rubidium Std (RB) outputs to XO which locks to the RB RFG-M-RB & RFG-M-XO (EFRATOM Labels on PCBs / LUCENT on Panel) WA5JAT
Microwave Frequency Standard RFG-M-RB These Screws Release the Rb unit from the tray P1 = DB9 Male Power Connector Pin 1 = +24 VDC Pin 2 = Common 10 MHz Output 15 MHz Output WA5JAT
Microwave Frequency Standard RFG-M-RB Rear Panel Removed Rubidium Std House Keeping Sub-Unit WA5JAT
Microwave Frequency Standard RFG-M-RB These Screws Release the RB Sub-unit after Rear panel removal The RB Sub-Unit Slides Sidewise and Unplugs WA5JAT
Microwave Frequency Standard LPRO-101 10 MHz Sine Output WA5JAT
Microwave Frequency Standard Supplier Specification Sheet Source: http://www.datasheetarchive.com/ WA5JAT
Microwave Frequency Standard Comparison of Several Frequency Sources Source: http://www.leapsecond.com/museum/manyadev.gif WA5JAT
Microwave Frequency Standard Comparison of Several Rubidium Sources Source: http://www.leapsecond.com/museum/lpro/ WA5JAT
Microwave Frequency Standard How Do You Use 10 MHz for a Microwave Frequency Standard? Direct Digital Synthesis (DDS) Phase Locked Loop Followed by Multipliers to the Band of Interest WA5JAT
Microwave Frequency Standard Direct Digital Synthesis (DDS) 10 MHz In – 96 MHz Output Source: NTMS FEEDPOINT Vol. 21, Issue 2 / WW2R WA5JAT
Microwave Frequency Standard Phase Lock Loop (N5AC/Down East Microwave) 10 MHz in - 1152 MHz Output (And 49 Others Available) Frequency Selection Jumpers Source: http://www.downeastmicrowave.com/PDF/A32_pd.pdf Also See: http://www.n5ac.com/apolLO-32Operation.pdf WA5JAT
Microwave Frequency Standard Example of a Frequency Multiplier Source: http://www.w1ghz.org/MBT/multiband.htm WA5JAT
Microwave Frequency Standard Questions? WA5JAT
Microwave Frequency Standard RFG-M-XO Front View Back View (Rear Panel Removed) WA5JAT
Microwave Frequency Standard Top View RFG-M-XO WA5JAT
Microwave Frequency Standard Bottom View RFG-M-XO WA5JAT
Microwave Frequency Standard Internet Search Came Up with: ]> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.c Sent: Friday, December 29, 2006 6:44 AM Subject: Re: [time-nuts] Lucent RFG-M-RG and XO > Back when these Lucent units were first appearing GPS had not yet been > implemented at the cell sites here in Alaska. The rubidium was too noisy > for direct frequency synthesis, so the XO unit was phase locked to the rubidium > to provide the long-term stability needed, and the XO output was > up-converted for the system clock. By using the XO to smooth the rubidium > output the phase noise in the system clock was reduced due to better > short-term stability in the XO. As I remember it (It's been a while) the > 10M Rb disciplined the 10M XO, which was divided by 2, multiplied by 3, > filtered, and supplied as the 15M system clock. The XO was always > supplying the 15M system clock, and "standby" just meant the XO was locked to the > rubidium, which was acting as the primary frequency reference. When the > rubidium failed the system alarm output went high, XO PLL went into hold, > the standby light on the XO extinguished, and the undisciplined XO became > the source until the rubidium could be replaced. The GPS connection didn't > appear until later units and disciplined the XO during normal operation, > with failover on extended GPS loss to disciplining the XO from the > rubidium. WA5JAT
Microwave Frequency Standard Internet Search Also Came Up with: Sent: Monday, October 31, 2005 4:56 PM Subject: Re: [time-nuts] Unknown Efratom 10MHz Assy, information asked > The board you are describing is used in the Lucent RFG-M-XO reference > frequency generator. It takes in 10 MHz on J2 from a Rubidium oscillator and > disciplines the Efratom SC cut OCXO on the main board from the 10 MHz input. > The output from the OCXO is converted to 15 MHz and supplied as the reference output on J4. > The RFG-M-RB and RFG-M-XO normally mount together in a chassis (which I didn’t > get) and the modules are connected to the chassis by a harness with a > DB15 on the chassis end. The pin out for the harness is as follows: > DB15M TO/Pin# Description > Pin # > 1 RFG0 - P1-1 +24v 1.3A/0.6A > 2 RFG0 - P1-2 Common > 3 RFG1 - P1-1 +24v 0.6A/0.4A > 4 RFG1 - P1-2 Common > 10 RFG0 - J3-1 Alarm > 11 RFG0 - J3-2 Alarm > 12 RFG1 - J3-1 Alarm > 13 RFG1 - J3-2 Alarm > > A second interface cable ties the RB to the XO as follows: > RBJ5 XOJ5 > Pin # Pin# > 1 5 > 3 3 > > The male DB9 is P1 and pin 1 = +24v @ 400ma, Pin 2 = Common. This will power > up the board so you can verify operation of the OCXO. Unfortunately that is > all the information I have on the unit. WA5JAT
Microwave Frequency Standard Internet Search Also Came Up with: Repair of Rubidium Source Author, G Molenkamp, ( vk3fgjm@commtelns.com) WA5JAT
Microwave Frequency Standard Repair of Rubidium Source-Cont’d WA5JAT
Microwave Frequency Standard Repair of Rubidium Source-Cont’d WA5JAT