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SG504: Difference between revisions
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Added service notes
Jaredcabot (talk | contribs) (Added service notes) |
Jaredcabot (talk | contribs) (Added service notes) |
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**L48 should always be completely compressed. | **L48 should always be completely compressed. | ||
**L45 may help harmonics by really playing with it. | **L45 may help harmonics by really playing with it. | ||
*SG504 HARMONIC DISTORTION AND LEVELING IMPROVEMENTS | |||
**The following changes have been made to improve performance and reliability of the SG504 from S/N B011080: | |||
***1. The two coax cables (P/N 175-0323-00) connecting the output of the low and high band oscillator cavities (A40) to the two input buffer transistors (A2070 , A2Q120) have been shortened from 3.0 inches to 2.687 inches. This improves the 550 MHz high band harmonics about 2dB. The new cable part number is 175-1870-00. | |||
***2. A 33pf capacitor, A2C1761 (P/N 281-0819-00) has been installed from the base of A2Q170 to ground as shown in Figure 1 below. This change improves output levelling at 1 GHz. | |||
**The above changes should be incorporated in any A2 RF boards with P/N 670-4038-00. | |||
==Pictures== | ==Pictures== | ||
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015-0282-00_7.jpg | Output head | 015-0282-00_7.jpg | Output head | ||
015-0282-00_8.jpg | Output head | 015-0282-00_8.jpg | Output head | ||
SG504_ServiceNote_Fig1.png|Service Note Fig.1 | |||
</gallery> | </gallery> | ||