>>> LOA1K RF SOURCE <<<

  The assembly shown in Figure 1 and 2 is a broadband RF source that covers 265 to 1060 MHz with a single jumper setting of the onboard ECL Prescaler IC.   The LOA1K Circuit Diagram of Figure 3 is included to clarify assembly operation.  The frequencies in these bands are set by tuning the onboard VCO between 1060 and 2120 MHz  (1.0 V < V-T < 16.00 V).   Figures 4 through 6 show the LOA1K Output Power of each Band.  Tables 1 through 4 show the power level of the fundamental, 2nd , and 3rd harmonic of the LOA1K measured with a spectrum analyzer.  To use this RF source for receiver testing, add 60 to 120 dB of attenuation on the output, and, if necessary, connect a LOW PASS FILTER to the source output to attenuate the 2nd and 3rd harmonic.  To drive the LO Port on a double balanced mixer, add 3 dB to10 dB of attenuation between the LOA1K output and the input of a MWA23 or HUA23 VHF/UHF amplifier.  For swept frequency and FM applications, the VCO Driver, VCOTC, is required.  A  complete RF Generator can be viewed by clicking on this hyperlink, GA10C SWEEP/SIGNAL GENERATOR.

  Table 1 shows what frequency band is selected when the SW short of Figure 2 is installed or removed.  The SB short when installed puts the ECL Prescaler IC in the stand by mode (SB) resulting in no output until the jumper is removed.

Band Divide Ratio Jumper SW Jumper SB VCO @ 1060 MHz VCO @ 2120 MHz
A 4 ON OFF 260 MHz 530
B 2 OFF OFF 530 1060
-- -- -- ON No Output No Output

Table 1, Band Select

===

Figure 1, LOA1K Printed Circuit Assembly Side 1

===

Figure 2, LOA1K Printed Circuit Assembly Side 2

===

Figure 3, LOA1K Circuit Diagram

===

Figure 4, Divide Ratio 4 Output Power Plot

===

Figure 5, Divide Ratio 2 (Band C) Output Power Plot

===

  This first group of Spectrum Analyzer measurements were performed with the VCO set to 1060 MHz (V-T = 1.35 VDC)

 

FUNDAMENTAL

2ND HARMONIC

3RD HARMONIC

OUTPUT FREQUENCY (MHz)

265

530

795

OUTPUT POWER (dBm)

4.90

-17.81

-9.54

 Table 1, ECL Prescaler IC set to divide by 4

===

 

FUNDAMENTAL

2ND HARMONIC

3RD HARMONIC

OUTPUT FREQUENCY (MHz)

5.30

1060

1590

OUTPUT POWER (dBm)

0.23

-10.37

-20.07

 Table 2, ECL Prescaler IC set to divide by 2

===

  This next group of Spectrum Analyzer measurements were performed with the VCO set to 2000 MHz (V-T = 17.116 VDC).

 

FUNDAMENTAL

2ND HARMONIC

3RD HARMONIC

OUTPUT FREQUENCY (MHz)

530

1060

1590

OUTPUT POWER (dBm)

1.94

-19.88

-24.12

 Table 3, ECL Prescaler IC set to divide by 4

===

 

FUNDAMENTAL

2ND HARMONIC

3RD HARMONIC

OUTPUT FREQUENCY (MHz)

1060

2120

3180

OUTPUT POWER (dBm)

-3.94

 

 

 Table 4, ECL Prescaler IC set to divide by 2

===

GA10C SWEEP/SIGNAL GENERATOR

===

AZD HOME PAGE