Kalaeloa KAL 16.046 MHz until 3/2/2014
Kakaako KAK 27.3 MHz starting 10/2014
Serial DDS-1-06
Last Updated: 01/04/16
- VECTRON serial number: 3076147-0017
- Novatech primary serial: 18
- Novatech secondary serial: 17
- LO-BUF board: 06
- LO-DIST board: 06
- power supply board: 06
1. Checklist
- DC input ferrite (tied down): V
- fan shroud (glued down): V
- clock grounding strap: V
- USB FTDI grounding strap: V
- VGA board clears LO-DIST board: V
- IQ cables from DDS-1 to LO-DIST same length: V
- remove auxilary heater regulator: V
- solid contacts at crimped connectors: V
- heatsink clued to each DDS: V
- thermal foam under and in front of clock bell: V
- heat shrink at 12 V splitter: V
- tape marking 12 V and 5 V on cables to LO-DIST and LO-BUF boards: V
- relay control connected to BNC: V
- front panel fiber optics blink: V
- fan and velcro, tied down at (11,11.5) cm: V
- jumpers
- serial enable, DDS1 and DDS2 boards: VV
- external clock, DDS1 and DDS2 boards: VV
- VCO disable, CLK board: V
- external clock, LO-BUF board: V
- triple, 2/22 dBm TX output, on 22 dBm, glued, LO-DIST board: VVV
- TUF source internal, LO-DIST board: V
- 0-Ohm resistance on divide by 2, LO-BUF board: V
2. Power supply measurements
(use EDAC 10953A 12 V 80 W adapter only)
- DC voltage 12 V input: 12.18 V
- DC voltage 5V PSU output (V): 4.96 V
- DC voltage -5V PSU output (V): -4.77 V
- DC current reading (A): 1.61 A (clock warmed up, chirping)
- AC power reading (A): 23.3 W
- temperature brass bell/air: 42/23 C
3. Program DDS
Connect USB to linux, check that /dev/ttyUSB{0,1,2,3} appear, open screen to each of them and check red/green LED blink on FTDI board. Verified: VVVV
For production, the Vectron clock is used /4 at 25 MHz, and the LO-BUF board is used to distribute the clock to the DDS boards. DO NOT connect the 50 MHz output of the Vectron directly to the DDS, as there may be issues with the correct KP setting at boot time.
Primary and secondary DDS, reset to factory default and clear parameter memory:
CLR
S
Power cycle and check with frequency meter that they both output 8.8817842 MHz, the default of 10 MHz scaled by the clock ratio. Then, proceed with programming.
Primary DDS, record commands:
F1 13.900482519779
Fd 0.000000002218
Td 1
Tr 52428800
M 3
A D
VQ 3600
VI 3600
S
QUE string:
000000000CA47552A2E30000000000000000000008AA03200000000001104A87600E100E10000FFF
Secondary DDS, record commands:
F0 13.900575577403
M 0
A D
S
QUE string:
000000000CA47ADE953B00000000000000000000000000000005000000104A00400FFF0FFF000FFF
4. Signals measurements and adjustments
Frequency meter:
Clock: temporarily set jumper to VCO on, using Rb external clock and frequency counter, set back to VCO off after tuning
- adjust VCO to 50.000000 MHz: V
- check auxiliary DDS1 and DDS2 clock output 25 MHz: V
- check Trig chirp length to match programmed DDS1: 3.178917 Hz
- check D-Tacq clock output 12.5 MHz: V
- check bandwidth on spectrum analyzer: 100 kHz centered at 12.000 MHz OK
RF power meter: Mini Circuits PWR-SEN-6G+ USB power sensor
Note: terminate all back panel open connectors with 50 Ohm while measuring
- probe on I1=I2, adjust DDS1 I channel so that output is -3 dBm
- probe on TX, adjust LO-DIST pot so that output is +18 dBm
- enable calib mode, adjust DDS2 so that output is +18 dBm
- probe on Q1=Q2, adjust DDS1 Q channel so that output is -3dBm, in software with VQ command:
VQ
S
QUE string
Oscilloscope on 1 MOhm input:
- Audio out adjust to max. gain CCW: 112 mVpp
- Trig, check pulse on SMA: 4 Vpp 980us
Disable clock VCO, power cycle and verify that it comes back with all the parameters OK: V
